Cisco CVA122/CVA122E Cable Voice Adapter Features

This feature module describes the Cisco CVA120 Series Cable Voice Adapters, its major benefits, and how to configure it. This document includes the following major sections:

Feature Overview

The Cisco CVA120 Series Cable Voice Adapters is a residential voice-enabled cable modem that provides high-speed data and voice services to home offices and homes over an Internet Protocol (IP). The Cisco CVA120 Series Cable Voice Adapters can deliver data at speeds exceeding analog dial up or Integrated Services Digital Network (ISDN) lines. The supported telephony features allow the Multiple Service Operator (MSO) to provide primary line voice service and secondary line service, using a single coaxial cable connection.

The Cisco CVA120 Series Cable Voice Adapters functions at its most basic level as a cable modem—a modulator/demodulator that provides high-speed network access on the cable television system to residential and small office/home office (SOHO) subscribers.

The Cisco CVA120 Series Cable Voice Adapters can optionally provide Voice over IP (VoIP) services, allowing subscribers to make telephone, modem, and fax calls over TCP/IP networks such as the Internet. These calls can be made to other VoIP devices, or to telephone, modem, or fax devices on the regular telephone network (the Public Telephone Switched Network, commonly known as PTSN). Custom class features such as 3-way calling, caller id, call return, and distinctive ringing are supported.

The Cisco CVA120 Series Cable Voice Adapters is equipped with both an Ethernet port and USB port. An optional uninterruptible power supply (UPS) can also provide power to the unit when the main AC-input power supply fails. The cable voice adapter is also designed to configure easily after installation by automatically registering itself on the network.

Cisco CVA120 Series Cable Voice Adapter Models

The Cisco CVA120 Series Cable Voice Adapter is available in two models, depending on the cable networking standard that is being used:

Both models of the Cisco CVA120 Series Cable Voice Adapter feature one F-connector interface to the cable system, one RJ-45 (10BASE-T Ethernet) hub port, one USB device port, and two RJ-11 analog voice ports. The USB interface enables the cable voice adapter to connect to a PC with a USB interface, without having the user to open the unit and install an Ethernet network interface card (NIC). If supported by the PC and service provider, PCs can be connected to the cable voice adapter using both the Ethernet and USB interfaces.

The Cisco CVA120 Series Cable Voice Adapter uses its cable interface to connect to the CMTS over the Hybrid/Fiber Coax (HFC) cable system. A personal computer (PC) connects to the Cisco CVA120 Series Cable Voice Adapter through either the Ethernet or USB interface. The Cisco CVA120 Series Cable Voice Adapter then provides Internet access by forwarding traffic between the PC and the CMTS. Subscribers can use the Cisco CVA120 Series Cable Voice Adapter to create high-speed, permanent access to the Internet, without the need for telco-based services such as leased lines.

If supported by the service provider, the Cisco CVA120 Series Cable Voice Adapter can connect to multiple PCs by attaching a PC to each interface (Ethernet and USB). In addition, the Cisco CVA120 Series Cable Voice Adapter's Ethernet interface can connect to an Ethernet hub, and multiple computers can then be connected to the hub.

Bridging Operations

The Cisco CVA120 Series Cable Voice Adapter provides IP bridging for one or more PCs and other customer premises equipment (CPE) when acting as a DOCSIS/EuroDOCSIS-compliant cable modem. In bridging mode, traffic from the cable voice adapter's Ethernet and USB interfaces is transparently forwarded on to the cable interface for transmission to the CMTS. Similarly, the cable voice adapter receives traffic on the cable interface and forwards it to the PCs attached to the Ethernet and USB interfaces.

You can connect a PC directly to the Ethernet port or to the USB port. You can connect a PC to both the Ethernet and USB ports, if this configuration is supported by the service provider.

In bridging mode, if only one PC is connected to both the Ethernet and USB interface ports, the cable voice adapter learns which port is in operation first, puts that MAC address in the bridge table, and forwards traffic from that port to the cable interface. If CPE devices are connected to both the Ethernet and USB ports, both ports are active. In this case the first CPE device that generates an Address Resolution Protocol (ARP) request that maps its IP address to a MAC address is put into the bridge table first and that CPE device will have its traffic forwarded first.

Also, if supported by the service provider, you can connect an Ethernet hub directly to the Ethernet port and then connect multiple PCs to the hub. In bridging mode, the Cisco CVA120 Series Cable Voice Adapter supports a maximum 254 PCs, depending on the maximum number allowed by the CMTS.

By default, one PC is supported for each Cisco CVA120 Series Cable Voice Adapter. This PC can be connected to either the Ethernet port or the USB port. If two PCs are connected to each port, then only the first PC that is discovered is allowed to access the network. The service provider can change this limit by changing the MAX CPE parameter in the DOCSIS configuration file. However, the CMTS at the headend can also enforce its own limit on CPE devices, and the CMTS limit overrides the MAX CPE parameter. So if the headend allows only one PC per cable voice adapter, subscribers can connect only one PC to the cable voice adapter, even if the MAX CPE parameter is set to the maximum value of 254.

The Cisco CVA120 Series Cable Voice Adapter ships from the factory with a Cisco IOS software image stored in nonvolatile Flash memory that supports DOCSIS/EuroDOCSIS-compliant IP bridging data operations.

Voice Operations

The Cisco CVA120 Series Cable Voice Adapter supports Voice over IP (VoIP), which transmits voice, modem, and fax calls over a TCP/IP network such as the Internet. Depending on the services purchased from the cable service provider, subscribers can place and receive calls without using the local exchange carrier.

The cable voice adapter contains two voice ports, which support two simultaneous voice, modem, and fax calls. You can connect a single-line analog telephone, fax, or modem device to each voice port, or you can connect a dual-line telephone device to the first voice port.

You can also connect multiple telephones, modems, and fax devices to each of the voice ports. However, the multiple telephones act as extensions to each voice line, so that only one call at a time can be made per voice port.

Voice signals are packetized and transported in compliance with the following protocols:

The CMTS at the headend routes IP telephony calls from the point of origination to the destination, transmitting them along with other traffic (both voice and data). To route voice calls across the local IP network to a destination on the Internet or the Public Switched Telephone Network (PSTN), the Cisco CVA120 Series Cable Voice Adapter and CMTS deploy IP telephony as a local-loop bypass service.

One of the following call routing methods is then used, depending on the protocol being used:

The gateway at the destination typically interconnects the IP network to the Public Switched Telephone Network (PSTN) so that calls can be made to any phone, not just those that are part of the IP telephony network.

Voice calls are digitized, encoded, compressed, and packetized in an originating gateway; and then, decompressed, decoded, and reassembled in the destination gateway. A server maintains subscriber profiles and policy information. See the Cisco service provider voice documentation set if you have Cisco gatekeeper, gateway, or other applicable products.

Voice Handling

Typically, voice calls made using the Public Switched Telephone Network (PSTN) require 64 Kbps of bandwidth when transmitted across digital systems. With IP telephony, however, telephone calls can be delivered at rates as low as 8000 bps in a packet format using different compression algorithms. Depending on the Cisco IOS software image being used, the Cisco CVA120 Series Cable Voice Adapter supports the following algorithms:

To achieve acceptable voice quality and reduce network bandwidth usage, several voice processing techniques are used. Digital Signal Processors (DSPs) provide the stream-to-packet and packet-to-stream conversion, and voice processing capabilities. Typical voice processing services include echo cancellation, voice compression, Voice Activity Detection (VAD) or silence compression, and Dual Tone Multi-Frequency (DTMF) tone detection and generation.

Quality of Service Support

Data traffic typically is sent only on a "best effort" basis, and if a packet is lost or delayed, it can be easily retransmitted without significantly affecting the connection. Such delays and losses are unacceptable, however, for real-time traffic such as voice calls.

For this reason, the CMTS and cable voice adapter router assign separate service identifiers (SIDs) for the voice and data traffic flows. Each SID has a separate class of service (CoS) that determines how its traffic flow is handled, allowing voice traffic to have a higher priority than the data traffic.

The CMTS and router can use different traffic shaping mechanisms to ensure that the higher priority voice traffic always has the bandwidth it needs. This allows voice calls (and other real-time traffic) to share the same channel as data traffic, without the quality of the voice calls being degraded by bursty data transmissions.

The Cisco CVA120 Series Cable Voice Adapter supports the following service classes:

This service class is assigned to the primary SID for the cable voice adapter. In addition to being used for data traffic, the cable voice adapter uses this SID for all MAC message exchanges with the CMTS, and for SNMP management traffic.

All traffic using this SID is transmitted on a "best effort" basis, but data traffic within this class can be prioritized into eight different priority levels. Although all data traffic still has lower priority than the voice traffic, this allows certain data traffic (such as MAC messages) to be given higher priority than other data traffic. The CMTS system administrator defines the traffic priority levels and must include the traffic priority fields in the configuration file downloaded to the cable voice adapter.

The CMTS system administrator typically configures these secondary classes of service so that they have higher quality of service (QoS) classes for use by higher priority voice traffic. These classes should also have a minimum upstream data rate specified for the channel to guarantee a specific amount of bandwidth for the corresponding traffic flows. When static SIDs are used, that bandwidth is always reserved for voice calls; however, when dynamic multi-SID assignment is used, that bandwidth is reserved only when the voice calls are active.

H.323v2 Protocol

In architectures using the VoIP H.323v2 protocol stack, the session application manages two call legs for each call: a telephony leg managed by the voice telephony service provider, and the VoIP leg managed by the cable system operator—the VoIP service provider. Use of the H.323v2 protocol typically requires a dial plan and mapper at the headend or other server location to map IP addresses to telephone numbers.

When both legs of the call have been set up, the session application creates a conference between them. The opposite leg's transmit routine for voice packets is given to each provider. The CMTS router passes data to the gateway and gatekeeper. The H.323v2 protocol stack provides signaling using H.225 and feature negotiation using H.245.

To make and receive H.323 calls, the Cisco CVA120 Series Cable Voice Adapter must be configured for the following:

SGCP and MGCP Protocol Stack

The Cisco CVA120 Series Cable Voice Adapter supports the Simple Gateway Control Protocol (SGCP) and Media Gateway Control Protocol (MGCP). Both MGCP and SGCP are signaling protocols that interact with a remote call agent (CA) to provide call setup and teardown for VoIP calls.

Using the call agent, SGCP and MGCP communicate with the voice gateways, dynamically resolving and routing calls. This creates a distributed system that enhances performance, reliability, and scalability while still appearing as a single VoIP gateway to external clients.

The remote call agent also provides the signaling and feature negotiation that would otherwise be provided by the Cisco CVA120 Series Cable Voice Adapter when using the H.323v2 protocol. Similarly, the call agent also provides the mapping of IP addresses to telephone numbers, eliminating the dial plan mapper and static configurations that are required on the router when using the H.323v2 protocol.

The SGCP and MGCP protocols implement the gateway functionality using both trunk and residential gateways. The Cisco CVA120 Series Cable Voice Adapter functions in this mode as a residential gateway with two endpoints.

SGCP and MGCP can preserve Signaling System 7 (SS7) style call control information, and preserve additional network information such as routing information and authentication, authorization, and accounting (AAA) security information. SGCP and MGCP allow voice calls to originate and terminate on the Internet, and allow one end to terminate on the Internet and the other to terminate on a telephone on the PSTN.

IP Routing Operations

The Cisco CVA120 Series Cable Voice Adapter can be configured for IP routing mode. To operate in routing mode, the Cisco CVA120 Series Cable Voice Adapter supports:

Dynamic Host Configuration Protocol Proxy Support

When configured for DHCP proxy support, during startup the Cisco CVA120 Series Cable Voice Adapter sends a proxy DHCP request to the DHCP server using the Ethernet interface's MAC address. The DHCP server replies with a second IP address that the router assigns to either the Ethernet interface or to the NAT pool, depending on which option was specified.

Routing Information Protocol Version 2

When configured for routing mode, the Cisco CVA120 Series Cable Voice Adapter defaults to using the Routing Information Protocol Version 2 (RIPv2). In routing mode, the Cisco CVA120 Series Cable Voice Adapter automatically configures itself to use the headend's IP address as its IP default gateway. This allows the Cisco CVA120 Series Cable Voice Adapter to send packets not intended for the Ethernet interface to the headend.

RIPv2 routing is useful for small internetworks because it optimizes Network Interface Center (NIC)-assigned IP addresses by defining Variable-Length Subnet Masks (VLSMs) for network addresses, and it allows Classless Interdomain Routing (CIDR) addressing schema.

Upgrading the Software Image

When Cisco IOS images are updated to new releases, the service provider can download them as needed to Cisco CVA120 Series Cable Voice Adapters installed in the field (based on the software licenses purchased). See the Cisco CVA120 Series Cable Voice Adapter Release Notes for a complete list of features and Cisco IOS images that are currently supported.

Service providers can use the Cisco CVA120 Series Cable Voice Adapter's Media Access Controller (MAC) address to uniquely identify each particular unit in the field. The CMTS uses this value to download the proper DOCSIS configuration file to the Cisco CVA120 Series Cable Voice Adapter before beginning operation.

The DOCSIS configuration file can also contain the name of the software image that the Cisco CVA120 Series Cable Voice Adapter should be running. If necessary, the CMTS can also download the proper software image to the cable voice adapter and force it to reboot using the new image.

The download of the DOCSIS configuration file usually takes only a few seconds and is done every time the Cisco CVA120 Series Cable Voice Adapter reboots. The download of the software image can take several minutes to complete, during which time network connectivity is not available. However, the software image must be downloaded only once, until the subscriber needs to be updated with a new or updated image.

Downloading the Cisco IOS Software Image

A Cisco IOS software image is preloaded on the Cisco CVA120 Series Cable Voice Adapter before it is shipped from the factory. However, when updated software images are available, a new Cisco IOS software image can be downloaded to a cable voice adapter installed in the field.

The DOCSIS configuration file can contain a filename for the software image that the Cisco CVA120 Series Cable Voice Adapter runs. If this filename does not match the software image that is currently installed on the cable voice adapter, the cable voice adapter must use the TFTP protocol to download the new image from the server specified in the DOCSIS configuration file.

After the new software image has been downloaded, the Cisco CVA120 Series Cable Voice Adapter resets itself and repeats the entire power-on and provisioning process. This includes downloading the DOCSIS configuration file again. However, because the software image is stored in nonvolatile Flash memory, the cable voice adapter does not have to download it again—the software download occurs only when the service provider specifies a new software image filename in the DOCSIS configuration file.

If the Cisco CVA120 Series Cable Voice Adapter cannot download the new image, it retries the download, as many as 16 attempts. If the cable voice adapter still cannot download the image, it falls back to its previous software image and attempts to go online with that image.

The service provider can also force the Cisco CVA120 Series Cable Voice Adapter to download new software by putting a new image filename in the DOCSIS configuration file and resetting the cable voice adapter. This should be done only after warning the customer that the modem will be offline for several minutes.

Downloading the Cisco IOS Configuration File

The DOCSIS configuration file uses the type 43 Vendor-Specific Options field to specify that the Cisco CVA120 Series Cable Voice Adapter should download a Cisco IOS configuration file. See the "DOCSIS Configuration File" section for more information.

Upgrading the ROM Monitor Software

The Cisco CVA120 Series Cable Voice Adapter supports both a primary and secondary ROM Monitor (ROMMON). The primary ROMMON is permanently installed, but a secondary ROMMON is upgradable.

After power-on or a hard system reset, the primary ROMMON initially takes control. It then checks for the presence of a secondary ROMMON and if present, verifies that the secondary ROMMON has the correct checksum. If the secondary ROMMON passes these validation tests, the primary ROMMON then passes control to the secondary ROMMON, which then performs the power-on self-test and hardware initialization, and then loads and executes the Cisco IOS software image. Otherwise, the primary ROMMON remains in control and continues the boot process.

This approach allows the secondary ROMMON to be safely upgraded when new software is available. If the file transfer is interrupted, however, or if the new ROMMON software becomes corrupted, the primary ROMMON is still available to boot the cable voice adapter and load the Cisco IOS software image.

To upgrade the secondary ROMMON, use the copy tftp rommon: privileged EXEC command. See the following example:

If the download of the secondary ROMMON is successful, the cable voice adapter is automatically reloaded to transfer control to the new ROMMON.

Benefits

Voice Over IP

The multiple service operator (MSO) can offer telephony service to their customers, increasing the MSO's monthly revenues. Customers can receive additional services that are competitively priced with existing services. Since the Cisco CVA120 Series Cable Voice Adapter's software is Cisco IOS-based, it has been proven reliable and feature rich.

USB and Ethernet Ports

Having both USB and Ethernet ports, an MSO can meet the needs of the consumers. A home office consumer can connect multiple PCs or devices to the Cisco CVA120 Series Cable Voice Adapter using the Ethernet plug, and, simultaneously, another family member can use the USB port for a second computer.

Primary Line Support

By offering an Uninterruptible Power Supply (UPS) backup battery, the MSO allows the end user to place calls and receive calls through the Cisco CVA120 Series Cable Voice Adapter even though the power might be out. In the event of a power outage, the customer has phone service for two hours of continuous talk time or eight hours of stand-by. Additionally, the battery signals to the MSO if it needs service, so that the MSO can contact the customer to replace it. The battery also has an LED to alert the end customer if it is running low.

Plug-and-Play Registration

After the Cisco CVA120 Series Cable Voice Adapter is installed, it automatically registers itself on the network and retrieves an IP address. The cable voice adapter is easy to install and installs quickly, thus saving the MSO money.

Switched Interface

Because the USB and Ethernet can be configured as independent switched interfaces, consumers can protect their data. Where one user can access confidential information on a web site, the other user is incapable of interfering with that data. One end user could be on a corporate web site, while the other end user is in a chat room without compromising any corporate confidential information.

Investment Protection for the MSO

The MSO, knowing that Cisco supports the evolving standards, is able to offer new services. As the customer premises equipment (CPE) devices are roughly 50% of the network upgrade costs, the CPE has a software roadmap that supports new features and call controls. The Cisco CVA120 Series Cable Voice Adapter's hardware is designed with additional memory capacity that is adequate to plan for new features and call controls.

Restrictions

The DOCSIS 1.0 specification states that a CMTS cannot age-out MAC addresses for CPE devices, so the first PC that is connected to the Cisco CVA120 Series Cable Voice Adapter is normally the only one that the CMTS recognizes as valid. If a subscriber replaces an existing PC or changes its network interface card (NIC) to one that has a different MAC address, the CMTS does not allow the PC to come online because this exceeds the maximum number of CPE devices specified by the MAX CPE parameter. A similar result would occur if a user decides to move a PC from one Cisco CVA120 Series Cable Voice Adapter to another.

Related Documents

Refer to the following Cisco documents for related information. The documents can be found online at Cisco Connection Online (CCO) or on the Documentation CD-ROM. You can also order printed copies of most current documents.

Cisco CVA120 Series Cable Voice Adapter

CMTS Hardware Installation Publications

Cisco IOS Publications

Configuration Editor and Network Management Publications

Subscriber Publications

Supported Platforms

Supported Standards, MIBs, and RFCs

Standards

The Cisco CVA120 Series Cable Voice Adapter supports the following Data-Over-Cable Service Interface Specifications (DOCSIS) standards:

Information about these specifications is available at the CableLabs web site at http://www.cablelabs.com.

MIBs

Table 1 shows the cable-specific MIBs that are supported on the Cisco CVA120 Series Cable Voice Adapter.

RFCs

The Cisco CVA120 Series Cable Voice Adapter supports the following Request for Comments (RFC) specifications:

Prerequisites

Site Requirements

Before going to a subscriber site to install the Cisco CVA120 Series Cable Voice Adapter, verify that the following have been done:

Each service provider has its own recommendations and requirements for the CPE devices that are connected to the network. However, at the very minimum a PC should meet the requirements listed in Table 2.

Environmental

Follow the operating and nonoperating environmental site requirements for operation of the Cisco CVA120 Series Cable Voice Adapter, as specified in the Cisco CVA122/CVA122E Cable Voice Adapter Hardware Installation Guide.

Power

Follow the recommendations for power supply and power cord described in the Cisco CVA122 Cable Voice Adapter Hardware Installation Guide. Verify that the power source is within the values outlined in Appendix A of the Cisco CVA122/CVA122E Cable Voice Adapter Hardware Installation Guide.

Cabling

Follow the recommendations for radio interference, coaxial cable quality, and distance limitations described in the "Cabling" section of the Cisco CVA122/CVA122E Cable Voice Adapter Hardware Installation Guide.

Configuration Tasks

This section describes the tasks that must be done to configure the Cisco CVA120 Series Cable Voice Adapter for normal operation as a DOCSIS-compliant cable modem. Because of DOCSIS regulations and because of the size of most cable modem networks, configuring the cable voice adapter is not normally done manually. Instead, the following configuration files are created and made available to the cable voice adapter on servers running at the headend, so that it can automatically configure itself at system power-on and reset. Each task in the list indicates if the task is optional or required.

DHCP Server Configuration

The DOCSIS specification (SP-RFI-IO5-991105 or later revision) requires that a DOCSIS-compliant cable modem connect to a DHCP server at power-on or reset to establish temporary IP connectivity with the cable network. This enables the cable modem to download the additional configuration information needed to establish a permanent connection with the headend and cable network.

The DHCP server can be a CMTS with DHCP server capabilities (such as a Cisco uBR7200 series universal broadband router), or it can be a dedicated server located at the headend. The server can be configured manually for each cable modem, or the server can be part of an automated provisioning system such as Cisco Network Registrar (CNR).

After making a successful DHCP request, the cable modem contacts the ToD server to get the current date and time. The cable voice adapter also begins the TFTP download of the DOCSIS configuration file, which is described in the next section, "DOCSIS Configuration File."

DOCSIS Configuration File

The DOCSIS specification requires that a DOCSIS-compliant cable modem downloads a DOCSIS configuration file during its power-on or reset sequence. This file must be in the format described in the SP-RFI-IO5-991105 specification (or later revision) and must contain the information shown in Table 4.

Table 4 DOCSIS Configuration File Parameters

Parameter¹	Description
Radio Frequency Parameters
Downstream Frequency	Specifies the center frequency (in multiples of 62500 Hz) for the downstream channel to be used by the cable voice adapter. (This parameter does not need to be specified in the configuration file because the cable voice adapter will scan the downstream for available frequencies, but it can be specified to ensure that the cable voice adapter conforms to the provider's channel plan.)
Upstream Channel ID	Specifies channel ID for the upstream channel to be used by the cable voice adapter. (This parameter does not need to be specified in the configuration file because it can be set dynamically by the CMTS during provisioning.)
Network Access Configuration	Determines whether CPE devices attached to the cable modem are allowed access to the cable network. The default is to allow access for CPE devices (which is required for normal operations).
Class of Service
Class of Service ID	Specifies the ID for this class of service (1 through 16).
Maximum Downstream Rate	Specifies the maximum downstream data rate (in bits/sec) allowed for traffic associated with this class of service. (This is a limit, not a guarantee of service.)
Maximum Upstream Rate	Specifies the maximum upstream data rate (in bits/sec) allowed for traffic associated with this class of service. (This is a limit, not a guarantee of service.)
Upstream Channel Priority	Specifies the priority for upstream traffic (0 through 7, where 7 is highest priority).
Minimum Upstream Rate	Specifies the minimum upstream data rate (in bits/sec) that is guaranteed for traffic associated with this class of service.
Maximum Upstream Channel Burst	Specifies the maximum size of burst traffic to be allowed on this upstream channel. The size is specified in bytes, 0 through 65535, where 0 is no limit. If this field is set to a nonzero value, it should be set to at least 1800 so that it is greater than the maximum Ethernet frame size of 1518 plus the associated packet overhead).
Class of Service Privacy Enable	Specifies whether BPI encryption should be enabled on traffic associated with this class of service (1 enables BPI encryption, 0 disables BPI encryption).
Vendor Specific Options
Vendor ID	The three-byte Organization Unique Identifier for the vendor, which is also usually the first three bytes of the cable modem's MAC address. This value is usually expressed as a hexadecimal number. This field should be 00000C for Cisco Systems equipment.
Vendor-Specific Options	Contains any arbitrary values that are defined by the manufacturer of the cable modem. The Cisco CVA120 Series Cable Voice Adapter uses this field to identify the Cisco IOS configuration file that should be downloaded (if any). Arbitrary Cisco IOS commands can also be specified in this field.
SNMP Management
SNMP Write-Access Control and SNMP MIB Objects	Allows the service provider to set arbitrary SNMP attributes on the cable modem. For the Cisco CVA120 Series Cable Voice Adapter, these two fields are typically used to enable SNMP management of the cable voice adapter because SNMP management is disabled by default. Note If using the Cisco DOCSIS Cable Modem Configurator tool, you can enable SNMP management by filling in the IP address for the SNMP manager. The Configurator tool then prepares the proper MIB objects to enable SNMP access.
Baseline Privacy Interface Configuration
Authorize Wait Timeout	Specifies the retransmission interval, in seconds, of Authorization Request messages from the Authorize Wait state. Valid values are 2 through 30 seconds.
Reauthorize Wait Timeout	Specifies the retransmission interval, in seconds, of Reauthorization Request messages from the Authorize Wait state. Valid values are 2 through 30 seconds.
Authorization Grace Timeout	Specifies the grace period for re-authorization, in seconds. Valid values are 1 through 1800 seconds.
Operational Wait Timeout	Specifies the retransmission interval, in seconds, of Key Requests from the Operational Wait state. Valid values are 1 through 10 seconds.
Rekey Wait Timeout	Specifies the retransmission interval, in seconds, of Key Requests from the Rekey Wait state. Valid values are 1 through 10 seconds.
TEK Grace Time	Specifies the grace period for re-keying, in seconds. Valid values are 1 through 1800 seconds.
Authorize Reject Wait Timeout	Specifies how long, in seconds, a cable modem waits in the Authorize Reject Wait state after receiving an Authorization Reject. Valid values are 60 through 1800 seconds.
Customer Premises Equipment
Maximum Number of CPEs	Determines the maximum number of PCs and other CPE devices that can use the cable modem to connect to the cable network. The default value is 1. The Cisco CVA120 Series Cable Voice Adapter supports a maximum number of 254 CPE devices, but the CMTS can also impose its own limit on the number of CPE devices.
CPE Ethernet MAC Address	Configures the cable modem with the MAC addresses for one or more CPE devices that are allowed to connect to the cable network. Entering values in this field is optional because the cable modem can learn the MAC addresses of CPE devices dynamically, up to the maximum allowable number. However, DOCSIS cable modems give priority to the CPE devices whose MAC addresses are in the configuration file.
Software Upgrade
TFTP Software Server IP Address	Specifies the IP address for the TFTP server that will provide software images. This server does not necessarily have to be the same TFTP server that provided the DOCSIS configuration file.
Software Image Filename	Specifies the fully qualified path name for the software image that the cable modem should be running. If necessary, the cable modem uses TFTP to download this image from the software server.
Miscellaneous
Concatenation Support	Specifies whether the cable modem supports DOCSIS 1.1 concatenation of upstream packet requests.
Use RFC2104 HMAC-MD5	Specifies the algorithm used to compute the CMTS Message Integrity Check (MIC). If yes, the HMAC-MD5 algorithm specified in RFC 2104 is used; otherwise, the algorithm specified by RFC 1321 is used. (The algorithm used must match the one used on the CMTS.) Note Because the RFC 1321 algorithm can be reversed, Cisco strongly recommends the use of only the more secure HMAC-MD5 algorithm.

1 The DOCSIS configuration file also contains fields for one-way cable modems that use telco-return, but these fields do not apply to the Cisco CVA120 Series Cable Voice Adapter, which is a two-way cable modem.

Cisco IOS Configuration File and Commands

The DOCSIS configuration file uses the type 43 Vendor-Specific Options field to specify that the cable voice adapter should download a Cisco IOS configuration file. The Cisco IOS configuration file is an ASCII text file that contains the CLI commands needed to configure the Cisco CVA120 Series Cable Voice Adapter for advanced features that are not specified in the DOCSIS configuration file.

Downloading a Cisco IOS configuration file is not normally required for plug-and-play DOCSIS IP bridging. However, downloading a configuration file is required to configure the cable voice adapter for Voice over IP (VoIP) operations.

Table 5 shows the values that are entered in the Vendor-Specific Information Field (VSIF) to download a Cisco IOS configuration file.

An optional way of configuring the Cisco CVA120 Series Cable Voice Adapter is to specify individual CLI commands as part of the VSIF field in the DOCSIS configuration file. Table 6 shows the values that are entered to specify a CLI command that should be executed after the cable voice adapter processes the DOCSIS configuration file and comes online.

Configuration Examples

DOCSIS-Compliant IP Bridging (Data-Only Mode)

The DOCSIS-compliant IP bridging mode configures the Cisco CVA120 Series Cable Voice Adapter for data-only connection to the cable network and Internet. This is the default configuration.

This configuration example shows the following requirements for DOCSIS-compliant bridging:

Configuring for Routing Mode

The Cisco CVA120 Series Cable Voice Adapter must be configured for routing mode to use advanced features. The routing mode is also required if the PCs attached to the cable voice adapter are on a private network or on a different subnet than the subnet used by the CMTS.

The following steps are required to configure routing mode on the Cisco CVA120 Series Cable Voice Adapter:

To configure the Cisco CVA120 Series Cable Voice Adapter, log in to the router, enter global configuration mode, and enter the following commands:

To verify that routing is enabled, enter the show startup-config command. The following example shows a sample configuration file for basic data-only routing mode; the relevant commands are shown in bold.

Configuring Routing with DHCP Server

When in routing mode, the Cisco CVA120 Series Cable Voice Adapter can act as a DHCP server for the CPE devices it is connecting to the cable network. A service provider then does not have to be concerned about providing IP addresses to all of the PCs at a subscriber's site. Instead, the provider supplies a pool of IP addresses that the cable voice adapter then allocates to the PCs as needed.

To configure the Cisco CVA120 Series Cable Voice Adapter to act as a DHCP server, log in to the router, enter global configuration mode, and enter the following commands:

To verify that the DHCP server is enabled, enter the show startup-config command. A sample configuration file for a Cisco CVA120 Series Cable Voice Adapter acting as a DHCP server is displayed below. The relevant commands are shown in bold.

NAT/PAT Configuration

All Cisco IOS images for the Cisco CVA120 Series Cable Voice Adapter support both Network Address Translation (NAT) and Port Address Translation (PAT). This allows a private network that is connected to the cable voice adapter to use the same IP address when communicating through the cable interface to the Internet or other public networks.

With the Cisco CVA120 Series Cable Voice Adapter, the "inside" network is the private network connected to the cable voice adapter's Ethernet interface, and the "outside" network is the network accessed through the cable network (such as the Internet or a company Intranet). The inside addresses are translated to an external IP address that is valid in the outside network.

The following configuration shows an example of a Cisco CVA120 Series Cable Voice Adapter that performs NAT/PAT translation on all IP addresses connected to the cable voice adapter's Ethernet interface. The external IP address is overloaded so that multiple IP addresses on the internal network can use the same IP address over the cable interface; different port numbers are used to uniquely identify each device on the Ethernet interface. The relevant commands are shown in bold.

H.323v2 Static Bridging Configuration

The Cisco CVA120 Series Cable Voice Adapter can support voice calls using an H.323v2 static dialing map. This requires the following minimum configuration:

You must also specify the IP address for the destination host that will deliver the call to the telephony device (or if the destination device is an IP telephone, the IP address for that telephone). You can optionally specify an IP precedence level for the type of service (ToS) bits in the IP header to signify that these voice packets should be given higher priority in transit across the IP network.

You can also specify which coding/decoding (codec) algorithm should be used if it is not being done by the CoS.

These functions are done using the dial-peer command, as shown in the following table:

The following example shows a Cisco CVA120 Series Cable Voice Adapter set up to support bridging and a static H.323 dial map with the following characteristics:

H.323v2 Dynamic Mapping Configuration

The Cisco CVA120 Series Cable Voice Adapter supports using the Registration, Admission, and Status (RAS) protocol to allow a remote gatekeeper to translate phone numbers (E.164 addresses) to the IP addresses of specific dial peers. This allows the gatekeeper to maintain a central database of dial peers, so that this information does not have to be entered into static dial maps on every router that is acting as a voice gateway.

The example shown in this section assumes that Cisco Network Registrar (CNR) Version 3.0 or higher is being used as the DHCP server. CNR assigns the E.164 addresses to local voice ports and uses DHCP to define the E.164 addresses-to-port assignments.

The gatekeeper can be a Cisco router, such as the Cisco 3620, with a Cisco IOS image that supports the gatekeeper function. The Cisco CVA120 Series Cable Voice Adapter acts as the H.323v2 gateway and creates the dial peers, starts H.323 RAS gateway support, and registers the E.164 addresses with the gatekeeper. The gatekeeper resolves the remote peers' IP addresses when the cable voice adapter sends a request using RAS.

You must do the following to configure the Cisco CVA120 Series Cable Voice Adapter for dynamic mapping:

The following configuration shows a Cisco CVA120 Series Cable Voice Adapter configured for routing mode and using RAS dynamic mapping with the following characteristics:

SGCP Configuration

The Cisco CVA120 Series Cable Voice Adapter can use the SGCP protocol for routing voice calls. This transfers the dial mapping to an external call agent, so that the VoIP gateways do not have to be individually configured with the dial mappings.

You must do the following to configure the Cisco CVA120 Series Cable Voice Adapter for a dynamic mapping configuration:

The configuration functions are done using the commands shown in the following table:

The following configuration shows a Cisco CVA120 Series Cable Voice Adapter that uses SGCP for the routing of its voice calls. Two voice ports are defined. The relevant commands are shown in bold.

MGCP Configuration

The Cisco CVA120 Series Cable Voice Adapter supports the MGCP protocol for routing voice calls. This transfers the dial mapping to an external call agent or to a Media Gateway Controller, so that the VoIP gateways do not have to be individually configured with the dial mappings.

You must do the following to configure the Cisco CVA120 Series Cable Voice Adapter for MGCP routing of voice calls:

The configuration functions are done using the commands shown in the following table:

The following configuration shows a Cisco CVA120 Series Cable Voice Adapter configured in DOCSIS-bridging mode that uses MGCP for controlling its voice calls. The relevant commands are shown in bold.

Command Reference

This section describes the commands for the Cisco CVA120 Series Cable Voice Adapter that are new or changed from the commands described in the Cisco IOS Release 12.1 command reference publications. All other commands used with this feature are documented in the Cisco IOS Release12.1 command reference publications.

cable dhcp-proxy

To configure the Cisco CVA120 Series Cable Voice Adapter so that it configures its Ethernet interface or Network Address Translation (NAT) address pool with an IP address supplied by the DHCP server, use the cable dhcp-proxy cable interface command. To disable this feature (so that you can then manually assign an IP address to the Ethernet interface or NAT address pool), use the no form of this command.

When using this option, you must also use the following NAT configuration commands:

After configuring the Cisco CVA120 Series Cable Voice Adapter with the cable dhcp-proxy command, reboot the router. During the DOCSIS provisioning process, the router sends a DHCP client request to obtain an IP address for the cable interface.

The router then sends a proxy DHCP request to the DHCP server using the Ethernet interface's MAC address. The DHCP server replies with a second IP address that the router assigns to either the Ethernet interface or to the NAT pool, depending on which option was used in the cable dhcp-proxy command.

The following example configures the Cisco CVA120 Series Cable Voice Adapter so that it makes a proxy DHCP request to obtain an IP address for its Ethernet interface:

The following example creates a NAT address pool with the IP address assigned by the DHCP server; this IP address must be in the network attached to the Ethernet address (which in this case is 192.168.100.0).

cable-modem compliant bridge

To enable DOCSIS/EuroDOCSIS-compliant bridging for a cable access router interface at startup, use the cable-modem compliant bridge cable interface configuration command. To disable DOCSIS-compliant bridging (which is required to enable routing mode), use the no form of this command.

It is normally not necessary to enter this command in data-over-cable bridging applications because DOCSIS-compliant bridging is enabled by default. However, to configure the router for full transparent bridging or for routing mode, use the no form of the command and then configure the router as desired using the appropriate CLI commands.

The following example shows how to enter the cable-modem compliant bridge command for a cable access router interface, starting from global configuration mode:

cable-modem voip clock-internal

To enable the Cisco CVA120 Series Cable Voice Adapter's internal clock for VoIP calls, use the cable-modem voip clock-internal cable interface configuration command. To disable the cable voice adapter's internal clock, so that it uses the clock from the cable interface for VoIP calls, use the no form of this command.

This command enables the cable voice adapter's internal clock, allowing it to make VoIP calls over the Ethernet and USB interfaces even when the cable interface is down or disconnected. If the CMTS is a Cisco uBR7200 series with a Cisco Cable Clock Card, this command disables the use of that clock.

This command can be used when the cable voice adapter is in both DOCSIS IP bridging and routing mode. However, when the cable voice adapter is operating in DOCSIS IP bridging mode, VoIP packets are transmitted out only on the cable interface, so the router must be operating in routing mode to transmit voice packets out the Ethernet and USB interfaces.

dtmf-relay

To configure the Cisco CVA120 Series Cable Voice Adapter so that it transmits Dual-Tone Multifrequency (DTMF) tones as out of band signals during H.323 voice calls, use the dtmf-relay dial-peer voice configuration command. To return to the default configuration (which is to transmit DTMF tones as part of the voice traffic), use the no form of this command.

DTMF tones are generated when you press the keypad digits on a touch-tone phone. DTMF tones are most commonly used to dial calls, but they can also be used during a call to interact with an Interactive Voice Response (IVR) system, such as voicemail, automated banking services and so on. By default, DTMF tones are transmitted along with the regular voice traffic, but this can cause problems with some IVR systems.

In particular, IVR systems might not recognize DTMF tones when using highly compressed CODECs such as G.729a. These CODECs are highly optimized for voice frequencies, but they can distort DTMF tones, preventing IVR systems from recognizing the tones. To avoid this problem, use one or more of the following methods of transmitting DTMF tones in an out of band channel, separately from the voice traffic:

You can enable more than one DTMF relay option for a particular dial peer, to support multiple destinations that might use different methods. If you enable more than one option, and if the peer is capable of receiving DTMF in more than one of these formats, the router selects the DTMF format with the highest priority:

The following example configures an outgoing dial peer so that DTMF tones to that destination are transmitted using the Cisco RTP protocol, if this configuration is supported by the remote end; otherwise, the DTMF tones are transmitted using the H.245 signaling protocol.

The following example reconfigures the above dial peer and disables out of band DTMF signaling, so that the DTMF tones are sent inband, as part of the voice traffic:

h323-gateway voip bind srcaddr

To configure the Cisco CVA120 Series Cable Voice Adapter so that H.323 VoIP traffic is sent using the Ethernet interface's IP address, use the h323-gateway voip bind srcaddr interface configuration command. To return to the default configuration (which is to use the cable interface's IP address for H.323 VoIP traffic), use the no form of this command.

No defaults assigned. By default, H.323 traffic is transmitted with the IP address assigned to the cable interface.

The h323-gateway voip bind srcaddr command can be used with any interface, but it is primarily used with the Cisco CVA120 Series Cable Voice Adapter's Ethernet interface when configuring a virtual private network (VPN). In this configuration, the h323-gateway voip bind srcaddr command configures the router so that VoIP traffic is sent using the IP address of the Ethernet interface (as opposed to the default behavior, which is to use the IP address of the default outgoing interface, which is the cable interface).

The h323-gateway voip bind srcaddr command allows the enterprise network to maintain the H.323 gatekeeper and gateway in the enterprise network's address space. Without the h323-gateway voip bind srcaddr command, outgoing voice traffic uses the IP address of the cable interface. This requires that the H.323 gatekeeper and gateway be maintained in the cable service provider's address space, which is not desirable if the enterprise needs to control the voice network and VPN configuration.

The following example shows the Ethernet interface being configured with the IP address of 192.168.100.94, and that H.323 traffic will be transmitted using that IP address:

The following example disables the H.323 binding, so that H.323 voice traffic is transmitted using the cable interface's IP address:

interface cable-modem

To enter the interface configuration mode for the cable interface on a Cisco CVA120 Series Cable Voice Adapter, enter the interface cable-modem global configuration command.

When this command is entered, the Cisco CVA120 Series Cable Voice Adapter switches from global configuration mode to interface configuration mode.

The following example brings up cable access router interface 0 and displays the available cable-modem interface configuration commands:

interface usb

To enter the interface configuration mode for the Universal Serial Bus (USB) interface on a Cisco CVA120 Series Cable Voice Adapter, enter the interface usb global configuration command.

When this command is entered, the Cisco CVA120 Series Cable Voice Adapter switches from global configuration mode to interface configuration mode for the USB interface.

The following example enters the interface configuration mode for the USB interface:

ip address docsis

To specify that the cable access router should use the DHCP protocol to assign an IP address for its cable interface (as required by the DOCSIS specification), use the ip address docsis global configuration command. To disable the use of DHCP, use the no form of this command.

The cable access router uses the DHCP protocol, as required by the DOCSIS specification, to assign an IP address to its cable interface during system power-on.

The ip address docsis command configures the cable access router so that it obtains its IP address from a DHCP server at system power-on, which is a requirement for DOCSIS operation. Using the no ip address docsis command prevents the cable access router from operating in DOCSIS networks and should be used only in lab or test networks.

The cable access router defaults to configuring its cable interface with the ip address docsis command.

The following example configures the cable access router so that it obtains the IP address for its cable interface from a DHCP server:

ip http cable-monitor

To enable the Cisco CVA120 Series Cable Voice Adapter's onboard cable monitor web server, use the ip http cable-monitor global configuration command. To disable the cable monitor and turn off all access to the onboard Cisco web server, use the no form of this command.

This command enables the cable monitor, an onboard web server that displays current status, troubleshooting, and performance information. The cable monitor can be accessed in two ways:

Enabling the cable monitor also enables the Cisco web server that is onboard the Cisco CVA120 Series Cable Voice Adapter (which is the equivalent to giving the ip http server command). However, when the cable monitor is enabled, all other access, including CLI access, to the onboard web server is automatically disabled.

Disabling the cable monitor using the no ip http cable-monitor command also automatically disables the Cisco web server (which is the equivalent of giving the no ip http server command).

The URL-IP-address and URL-mask parameters also specify that the class C private network 192.168.100.0 is the default address pool for the temporary DHCP server that activates when the cable interface goes down.

The following example enables the cable monitor for advanced mode, in which all status and diagnostic pages are displayed:

The following example disables both the cable monitor and the Cisco web server, preventing all web server access to the Cisco CVA120 Series Cable Voice Adapter:

ping docsis

To determine whether a specific cable modem is online and reachable from the cable interface on the Cisco CVA120 Series Cable Voice Adapter, use the ping docsis privileged EXEC command.

The following example confirms that the cable modem at 172.00.00.00 is connected to the network and is operational:

show bridge cable-modem

To display bridging information for a Cisco CVA120 Series Cable Voice Adapter, enter the show bridge cable-modem privileged EXEC command.

show controllers cable-modem

To display high-level controller information about a Cisco CVA120 Series Cable Voice Adapter, use the show controllers cable-modem privileged EXEC command.

The show controllers cable-modem display begins with information from the first few registers of the Broadcom BCM3300 chip. Next is buffer information for the receive, receive MAC message, buffer descriptor, and packet descriptor rings. Then MIB statistics from the BCM3300 chip are shown, followed by DMA base registers to indicate where the rings start, global control and status information, and finally interrupts for the interrupt code.

When using this command, be sure to check the tx_count and the tx_head and tx_tail values for the buffer descriptor (TX BD) and packet descriptor (TX PD) rings. The tx_count should be greater than 0, and the tx_head and tx_tail values should not be equal. If these values do not change for a long period of time, this indicates there are packets stuck on the ring. This condition is often caused by the headend not giving grants.

Table 8 briefly describes some of the fields shown in the display. For more information, see the Broadcom documentation for the BCM3300 chip.

Table 8 show controllers cable-modem display

Field	Description
BCM3300 unit	The unit number of this BCM3300 chip.
idb	Interface description block number.
ds	Downstream channel.
regaddr	Indicates the start of the BCM3300 registers.
reset_mask	Indicates the bit to hit when resetting the chip.
station address	MAC address of this Cisco CVA120 Series Cable Voice Adapter interface.
default station address	Default MAC address assigned by the factory for this Cisco CVA120 Series Cable Voice Adapter.
PLD VERSION	PLD version of the BCM3300 chip.
MAC state	Current MAC state of the Cisco CVA120 Series Cable Voice Adapter.
Prev States	Number of states that have previously existed since initialization.
MAC mcfilter	MAC control filter for MAC messages.
data mcfilter	MAC control filter for data.
DS	Downstream Broadcom receiver chip number and ID.
US	Upstream Broadcom transmitter chip number and ID.
Tuner: status	Current status of the tuner.
Rx: tuner_freq	Downstream frequency (in Hz) that the Cisco CVA120 Series Cable Voice Adapter searched for and found.
symbol_rate	Downstream frequency in symbols per second.
local_freq	Frequency on which the transmitter and the tuner communicate.
snr_estimate	Estimate of signal-to-noise ratio (SNR) in Db X 1000.
ber_estimate	Estimate of bit error rate (always 0).
lock_threshold	Minimum signal-to-noise ratio (SNR) that the Cisco CVA120 Series Cable Voice Adapter will accept as a valid lock.
qam_mode	The modulation scheme used in the downstream direction.
Tx: tx_freq	Upstream frequency sent to the Cisco CVA120 Series Cable Voice Adapter by the CMTS in the UCD message.
power_level	Transmit power level as set in the hardware, expressed as a hexadecimal value. The units are unique to the hardware used. Use the show controllers cable-modem 0 mac state command to see the power level in dBmV.
symbol_rate	Upstream frequency in symbols per second.
TFTP server	IP address of the TFTP server at the headend.
TOD server	IP address of the time-of-day server at the headend.
Security server	IP address of the security server at the headend.
Timezone Offset	Correction received from the DHCP server to synchronize the Cisco CVA120 Series Cable Voice Adapter time clock with the CMTS.
Config filename	Name of the file stored on the cable company's TFTP server that contains operational parameters for the Cisco CVA120 Series Cable Voice Adapter.
buffer size	Size in bytes of the BCM3300 message buffers.
RX data PDU ring: rx_head rx_p	Indicates the memory location of the beginning of buffer information for the receive data ring. Indicates current head buffer descriptor. Indicates current head packet descriptor.
RX MAC message ring: rx_head_mac rx_p_mac	Indicates the memory location of the beginning of buffer information for the receive MAC message ring. Indicates current head buffer descriptor. Indicates current head packet descriptor.
TX BD ring: tx_count tx_head head_txp tx_tail tail_txp	Indicates the memory location of the beginning of buffer information for the transmit buffer descriptor ring. If tx_count is 0, or if tx_head and tx_tail are equal and there is no change for a period of time, this means there are packets stuck on the ring. This condition can be caused by the headend not giving grants. The next packet descriptor to get used, along with its index. The next packet descriptor to get sent, along with its index. When head_txp and tail_txp are the same, the transmit queue is empty.
TX PD ring: tx_head_pd tx_tail_pd ehdr	Indicates the memory location of the beginning of buffer information for the transmit packet descriptor ring. Indicates current head packet descriptor. Indicates current tail packet descriptor. Extended MCNS header.
MIB Statistics:
DS fifo full	Number of times the downstream input first-in first-out (FIFO) buffer became full on the Cisco CVA120 Series Cable Voice Adapter.
rerequests	Number of times a bandwidth request generated by the Cisco CVA120 Series Cable Voice Adapter was not responded to by the CMTS.
DS mac msg overruns	Number of times the Cisco CVA120 Series Cable Voice Adapter's DMA controller had a downstream MAC message and there were no free MAC message buffer descriptors to accept the message.
DS data overruns	Number of times the Cisco CVA120 Series Cable Voice Adapter' DMA controller had downstream data and there were no free data PDU buffer descriptors to accept the data.
Qualified maps	Number of times a MAP message passed all filtering requirements and was received by the Cisco CVA120 Series Cable Voice Adapter.
Qualified syncs	Number of times a timestamp message was received by the Cisco CVA120 Series Cable Voice Adapter.
CRC fails	Number of times a MAC message failed a cyclic redundancy (CRC) check.
HDR chk fails	Number of times a MAC header failed its 16-bit CRC check. The MAC header CRC is a 16-bit Header Check Sequence (HCS) field that ensures the integrity of the MAC header even in a collision environment.
Data pdus	Total number of data PDUs (protocol data units) of all types received by the Cisco CVA120 Series Cable Voice Adapter.
Mac msgs	Number of MAC messages received by the Cisco CVA120 Series Cable Voice Adapter.
Valid hdrs	Number of valid headers received by the Cisco CVA120 Series Cable Voice Adapter, including PDU headers, MAC headers, and headers only.
Global control and status:	Used to reset the BCM3300 chip.
interrupts:	Hexadecimal values of the pending IRQ interrupt and IRQ mask.

show controllers cable-modem bpkm

To display information about the baseline privacy key management exchange between the Cisco CVA120 Series Cable Voice Adapter and the headend CMTS, use the show controllers cable-modem bpkm privileged EXEC command.

Baseline privacy key management exchanges take place only when both the Cisco CVA120 Series Cable Voice Adapter and the CMTS are running code images that support baseline privacy, and the privacy class of service is enabled using the configuration file that is downloaded to the cable access router. Baseline privacy code images for the Cisco CVA120 Series Cable Voice Adapter contain k1 in the code image name.

The following output is displayed when the headend CMTS does not have baseline privacy enabled:

show controllers cable-modem des

To display information about the Data Encryption Standard (DES) engine registers, use the show controllers cable-modem des privileged EXEC command.

Table 10 briefly describes some of the fields shown in the display. For more information, see the Broadcom documentation for the BCM3300 chip.

show controllers cable-modem filters

To display the registers in the MAC hardware that are used for filtering received frames, use the show controllers cable-modem filters privileged EXEC command.

Some of the filtering parameters are MAC hardware addresses, Service IDs (SIDs), and upstream channel IDs.

Table 11 briefly describes some of the fields shown in the display. For more information, see the Broadcom documentation for the BCM3300 chip.

show controllers cable-modem lookup-table

To display the mini-slot lookup table inside a Cisco CVA120 Series Cable Voice Adapter, use the show controllers cable-modem lookup-table privileged EXEC command.

This command displays the details of the lookup table. The driver uses this table to convert the size of the packets that the Cisco CVA120 Series Cable Voice Adapter wants to transmit into a bandwidth request to the CMTS in mini-slots. The contents of this table are affected by the upstream symbol rate that is negotiated between the CMTS and the cable access router.

Use this table to look up the packet size and determine how many mini-slots are needed.

show controllers cable-modem mac

To display detailed MAC-layer information for a Cisco CVA120 Series Cable Voice Adapter, use the show controllers cable-modem mac command in privileged EXEC mode.

MAC log messages are written to a circular log file even when debugging is not turned on. These messages include timestamps, events, and information pertinent to these events. Use the show controllers cable-modem mac log command to view MAC log messages.

If the Cisco CVA120 Series Cable Voice Adapter interface fails to come up or resets periodically, the MAC log will capture what happened. For example, if an address is not obtained from the DHCP server, an error is logged, initialization starts over, and the Cisco CVA120 Series Cable Voice Adapter scans for a downstream frequency.

The most useful keywords for troubleshooting a Cisco CVA120 Series Cable Voice Adapter are log, errors, and resets. See the following examples for typical output.

Example 1

The following sample display shows the MAC log file for a cable-modem interface that has successfully registered with the CMTS:

If the DHCP server cannot not be reached, the error will look like this in the MAC log:

Example 2

MAC error log information is displayed in the following example, which is also reported using SNMP:

This output indicates that the Cisco CVA120 Series Cable Voice Adapter has acquired a downstream lock, successfully read a UCD, and successfully read a MAP. However, the cable voice adapter was unable to communicate with the CMTS after ranging through all upstream transmit power levels. The Cisco CVA120 Series Cable Voice Adapter tried to communicate with the CMTS 16 times without success, after which it reset the cable interface to try to find a better downstream frequency.

If the DHCP server could not be reached, the error would look like this in the MAC error display:

Example 3

The show controllers cable-modem 0 mac resets command shows only the entries in the MAC log that begin with the field CMAC_LOG_RESET. Collectively presenting these fields provides you with a summary of the most recent reasons why the cable interface was reset.

Reset messages and brief explanations are included in the following examples; however, the reset messages do not commonly occur.

In the following example, the configuration file downloaded from the TFTP server could not be read. The file might not exist, or the file might have incorrect permissions.

The following example shows that the DHCP server could not be reached, or that it took too long to respond.

The following example indicates that an event in the cable interface driver caused the interface to reset. This often occurs because the interface has just been shutdown or cleared.

Table 12 lists the fields displayed by the show controllers cable-modem mac resets command:

Table 12 show controllers cable-modem mac resets display

Message	Description
`CMAC_LOG_RESET_CONFIG_FILE_PARSE_FAILED`	The format of the DOCSIS configuration file acquired from the TFTP server is not acceptable.
`CMAC_LOG_RESET_LOSS_OF_SYNC`	Synchronization with the CMTS has been lost (SYNC messages are not being received).
`CMAC_LOG_RESET_T4_EXPIRED`	Maintenance ranging opportunities for this Cisco CVA120 Series Cable Voice Adapter are not being received from the CMTS.
`CMAC_LOG_RESET_DHCP_WATCHDOG_EXPIRED`	The DHCP server took too long to respond.
`CMAC_LOG_RESET_TOD_WATCHDOG_EXPIRED`	The Time Of Day server took too long to respond.
`CMAC_LOG_RESET_PRIVACY_WATCHDOG_EXPIRED`	The baseline privacy exchange with the CMTS took too long.
`CMAC_LOG_RESET_CHANGE_US_WATCHDOG_EXPIRED`	The Cisco CVA120 Series Cable Voice Adapter was unable to transmit a response to a UCC-REQ message.
`CMAC_LOG_RESET_SECURITY_WATCHDOG_EXPIRED`	The "full security" exchange with the CMTS took too long.
`CMAC_LOG_RESET_CONFIG_FILE_WATCHDOG_EXPIRED`	The TFTP server took too long to respond.
`CMAC_LOG_RESET_ALL_FREQUENCIES_SEARCHED`	All downstream frequencies to be searched have been searched. Note This message indicates that downstream frequencies were found, but the Cisco CVA120 Series Cable Voice Adapter failed to acquire a downstream lock.
`CMAC_LOG_RESET_T2_EXPIRED`	Initial ranging opportunities are not being received.
`CMAC_LOG_RESET_T3_RETRIES_EXHAUSTED`	The CMTS failed too many times to respond to a RNG-REQ message. Note After 16 T3 timeouts, the Cisco CVA120 Series Cable Voice Adapter will reset the cable interface.
`CMAC_LOG_RESET_RANGING_ABORTED`	The CMTS commanded the Cisco CVA120 Series Cable Voice Adapter to abort the ranging process.
`CMAC_LOG_RESET_NO_MEMORY`	The Cisco CVA120 Series Cable Voice Adapter has run out of memory.
`CMAC_LOG_RESET_CANT_START_PROCESS`	The Cisco CVA120 Series Cable Voice Adapter was unable to start an internal process necessary to complete ranging and registration.
`CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED`	The reading of the configuration file from the TFTP server failed. Note The file might not exist, or it might have incorrect permissions.
`CMAC_LOG_RESET_AUTHENTICATION_FAILURE`	The Cisco CVA120 Series Cable Voice Adapter failed authentication as indicated in a REG-RSP message from the CMTS.
`CMAC_LOG_RESET_SERVICE_NOT_AVAILABLE`	The CMTS has failed the Cisco CVA120 Series Cable Voice Adapter's registration because a required or requested class of service is not available.
`CMAC_LOG_RESET_T6_RETRIES_EXHAUSTED`	The CMTS failed too many times to respond to a REG-REQ message.
`CMAC_LOG_RESET_MAINTENANCE_WATCHDOG_DRIVER`	The Cisco CVA120 Series Cable Voice Adapter MAC layer failed to detect a change in the interface driver.
`CMAC_LOG_RESET_NET_ACCESS_MISSING`	The Network Access parameter is missing from the DOCSIS configuration file.
`CMAC_LOG_RESET_FAILED_WRITE_ACCESS_CONTROL`	The Cisco CVA120 Series Cable Voice Adapter was unable to set the Write Access Control for an SNMP parameter as specified by the DOCSIS configuration file.
`CMAC_LOG_RESET_DHCP_FAILED`	The DHCP server did not respond with all the required values. The required values are: IP address Network mask TFTP server IP address TOD server IP address DOCSIS configuration file name Time zone offset
`CMAC_LOG_RESET_CANT_START_DS_TUNER_PRCESS`	The Cisco CVA120 Series Cable Voice Adapter was unable to start the internal process that is used to manage the downstream tuner.
`CMAC_LOG_RESET_TOO_MANY_DS_LOCKS_LOST`	Downstream QAM/FEC lock has been lost too many times.
`CMAC_LOG_RESET_NO_SEND_TO_DS_TUNER_PROCESS`	The Cisco CVA120 Series Cable Voice Adapter MAC-layer process was unable to communicate with the downstream tuner management process.
`CMAC_LOG_RESET_DS_TUNER_WATCHDOG`	The downstream tuner process failed to report its continuing operation for a long period of time.
`CMAC_LOG_RESET_UNABLE_TO_SET_MIB_OBJECT`	The Cisco CVA120 Series Cable Voice Adapter was unable to set an SNMP parameter as specified by the DOCSIS configuration file.
`CMAC_LOG_RESET_MIB_OBJECT_PROCESS_WATCHDOG`	The internal MIB object took too long to process the entries in the DOCSIS configuration file.

Example 4

The following example display for the show controllers cable-modem 0 mac hardware command shows the detailed configuration of the interface driver and the MAC-layer hardware. The most informative piece of data is the station address (hardware address). The MIB statistics reflect the MAC hardware counters for various events, but these counters are typically reset every few seconds, so their contents are not accurate in this display.

Most of the fields in this display are described in Table 18; Table 13 describes the MIB statistics shown in the display.

Below the MIB statistics in the show controllers cable-modem 0 mac hardware display, the BCM3300 registers section shows the DMA locations of the indicated processing routines of the Broadcom 3220 MAC chip within the Cisco CVA120 Series Cable Voice Adapter.

Example 5

The show controllers cable-modem mac state command summarizes the state of the cable MAC layer and provides a list of downstream search frequency bands and the order in which they are searched. If the cable MAC layer is in the wait_for_link_up_state, the information shown in the display corresponds to the last time the interface was up. This allows useful information to be acquired from this display even though the modem has not been able to range and register. The normal operational state of the interface is the maintenance_state.

Table 14 show controller cable-modem mac state Display

Field	Description
MAC State	Current operational state of the MAC layer of the Cisco CVA120 Series Cable Voice Adapter.
Ranging SID	Service ID used for ranging requests.
Registered	Indicates whether or not the Cisco CVA120 Series Cable Voice Adapter is currently registered with the CMTS.
Privacy Established	Indicates whether or not keys for baseline privacy have been exchanged between the Cisco CVA120 Series Cable Voice Adapter and the CMTS, establishing privacy.
Mac Resets	Number of times the Cisco CVA120 Series Cable Voice Adapter reset or initialized this interface.
Sync lost	Number of times the Cisco CVA120 Series Cable Voice Adapter lost synchronization with the downstream channel.
Invalid Maps	Number of times the Cisco CVA120 Series Cable Voice Adapter received invalid MAP messages.
Invalid UCDs	Number of times the Cisco CVA120 Series Cable Voice Adapter received invalid UCD messages.
Invalid Rng Rsp	Number of times the Cisco CVA120 Series Cable Voice Adapter received invalid ranging response messages.
Invalid Reg Rsp	Number of times the Cisco CVA120 Series Cable Voice Adapter received invalid registration response messages.
T1 Timeouts	Number of timeouts caused by the Cisco CVA120 Series Cable Voice Adapter not receiving a valid upstream channel descriptor (UCD) from the CMTS within the specified time.
T2 Timeouts	Number of timeouts caused by the Cisco CVA120 Series Cable Voice Adapter not receiving a maintenance broadcast for ranging opportunities from the CMTS within a specified time.
T3 Timeouts	Number of timeouts caused by the Cisco CVA120 Series Cable Voice Adapter not receiving a response within a specified time from the CMTS to a RNG-REQ message during initial maintenance.
T4 Timeouts	Number of timeouts caused by the Cisco CVA120 Series Cable Voice Adapter not receiving a response within a specified time from the CMTS to a periodic maintenance request.
Range Aborts	Number of times the ranging process was aborted by the CMTS.
DS ID	Identifier of the downstream channel on which this MAC management message has been transmitted. This identifier is arbitrarily chosen by the CMTS and is only unique within the MAC-sublayer domain.
DS Frequency	Downstream frequency acquired by the Cisco CVA120 Series Cable Voice Adapter during its last initialization sequence.
DS Symbol Rate	Downstream frequency in symbols per second.
DS QAM Mode	Downstream modulation scheme being used by the Cisco CVA120 Series Cable Voice Adapter.
DS Search	Frequency bands scanned by the Cisco CVA120 Series Cable Voice Adapter when searching for a downstream channel. The Cisco CVA120 Series Cable Voice Adapter's default frequency bands correspond to the North American EIA CATV channel plan for 6 MHz channel slots between 90 MHz and 858 MHz.
US ID	Identifier of the upstream channel to which this MAC management message refers. This identifier is arbitrarily chosen by the CMTS and is only unique within the MAC-sublayer domain.
US Frequency	Transmission frequency used by the Cisco CVA120 Series Cable Voice Adapter in the upstream direction.
US Power Level	Transmit power level of the Cisco CVA120 Series Cable Voice Adapter in the upstream direction.
US Symbol Rate	Upstream frequency in symbols per second.
Ranging Offset	Delay correction (in increments of 6.25 milliseconds/64) applied by the Cisco CVA120 Series Cable Voice Adapter to the CMTS upstream frame time, derived at the Cisco CVA120 Series Cable Voice Adapter. Used to synchronize the upstream transmissions in the time division multiple access (TDMA) scheme, this value is roughly equal to the round-trip delay of the Cisco CVA120 Series Cable Voice Adapter from the CMTS.
Mini-Slot Size	Size T of the mini-slot for this upstream channel in units of the timebase tick of 6.25 µs. Allowable values are 2, 4, 8, 16, 32, 64, or 128.
Change Count	Incremented by 1 by the CMTS whenever any of the values of this channel descriptor change. If the value of this count in a subsequent upstream channel descriptor (UCD) remains the same, the Cisco CVA120 Series Cable Voice Adapter can quickly decide that the remaining fields have not changed, and can disregard the remainder of the message.
Preamble Pattern	Byte pattern used for the preamble.
Burst Descriptor: Interval Usage Code	A compound type/length/value (TLV) encoding that defines, for each type of upstream usage interval, the physical-layer characteristics that are used during that interval. Each burst descriptor is given an identifying number. Each upstream transmit burst belongs to a class which is given a number called the IUC (interval usage code). Bandwidth MAP messages are used by IUC codes to allocate upstream time slots. The following types are currently defined: 1. Request: bandwidth request slot 2. Request/Data: bandwidth request or data slot 3. Initial Maintenance: initial link registration contention slot 4. Station Maintenance: link keep-alive slot 5. Short Data Grant: short data burst slot 6. Long Data Grant: long data burst slot
Modulation Type	Upstream modulation format. (1 = QPSK; 2 = 16QAM)
Differential Encoding	Indicates whether or not differential encoding is used. (1 = yes; 2 = no)
Preamble Length	Length of the preamble in bits. This value must be an integral number of symbols—a multiple of 2 for QPSK; a multiple of 4 for 16QAM.
FEC Error Correction	Length of the forward error correction in bytes. The range is 0 through 10 bytes; a value of 0 implies no forward error correction.
FEC Codeword Info Bytes	Number of information bytes in the FEC codeword.
Scrambler Seed	15-bit seed value loaded at the beginning of each burst after the register has been cleared. Not used if scrambler is off.
Maximum Burst Size	Maximum number of mini-slots that can be transmitted during this burst type. When the interval type is Short Data Grant, this value must be greater than 0. If this value is 0, the burst size is limited elsewhere.
Guard Time Size	Amount of time in symbols between the center of the last symbol of a burst and the center of the first symbol of the preamble of an immediately following burst in an upstream transmission from the Cisco CVA120 Series Cable Voice Adapter to the CMTS.
Last Codeword Length	Indicates whether or not the length of the last codeword is fixed or shortened. (1 = fixed; 2 = shortened)
Scrambler on/off	Indicates whether or not a scrambler is enabled in the upstream modulator. (1 = on; 2 = off)
Network Access	Indicates whether or not the Cisco CVA120 Series Cable Voice Adapter has access to the HFC network.
Vendor ID	Unique identifier specifying the cable modem manufacturer.
Auth. Wait Timeout	Number of seconds the Cisco CVA120 Series Cable Voice Adapter waits for a reply after sending the Authorization Request message to the CMTS.
Reauth. Wait Timeout	Number of seconds the Cisco CVA120 Series Cable Voice Adapter waits for a reply after it has sent an Authorization Request message to the CMTS in response to a reauthorization request or an Authorization Invalid message from the CMTS.
Auth. Grace Time	Number of seconds before the current authorization is set to expire that the grace timer begins, signaling the Cisco CVA120 Series Cable Voice Adapter to begin the reauthorization process.
Op. Wait Timeout	Number of seconds the TEK state machine waits for a reply from the CMTS after sending its initial Key Request for its SID's keying material.
Retry Wait Timeout	Number of seconds the TEK state machine waits for a replacement key for this SID after the TEK grace timer has expired and the request for a replacement key has been made.
TEK Grace Time	Number of seconds before the current TEK is set to expire that the TEK grace timer begins, signaling the TEK state machine to request a replacement key.
Auth. Reject Wait Time	Number of seconds the Cisco CVA120 Series Cable Voice Adapter waits before sending another Authorization Request message to the CMTS after it has received an Authorization Reject message.
Assigned SID	Service ID assigned by the CMTS for the corresponding service class.
Max Downstream Rate	Maximum downstream rate in bits per second that the CMTS is permitted to forward to CPE unicast MAC addresses learned or configured as mapping to this Cisco CVA120 Series Cable Voice Adapter. (This does not include MAC packets addressed to broadcast or multicast MAC addresses.)
Max Upstream Rate	Maximum upstream rate in bits per second that the Cisco CVA120 Series Cable Voice Adapter is permitted to forward to the RF network. This includes PDU data packets addressed to broadcast or multicast addresses.
Upstream Priority	Relative priority assigned to this service class for data transmission in the upstream channel. Higher numbers indicate higher priority.
Min Upstream Rate	Date rate in bits per second that are guaranteed to this service class on the upstream channel.
Max Upstream Burst	Maximum transmit burst in bytes allowed for this service class on the upstream channel.
Privacy Enable	Indicates whether or not Baseline Privacy is enabled for this service class.
Ranging Backoff Start	Initial back-off window for initial ranging contention, expressed as a power of 2. Valid values are from 0 to 15.
Ranging Backoff End	Final back-off window for initial ranging contention, expressed as a power of 2. Valid values are from 0 to 15.
Data Backoff Start	Initial back-off window for contention data and requests, expressed as a power of 2. Valid values are from 0 to 15.
Data Backoff End	Final back-off window for contention data and requests, expressed as a power of 2. Valid values are from 0 to 15.
IP Address	IP address of the cable interface.
Net Mask	Subnet mask of the cable interface.
TFTP Server IP Address	IP address of the CMTS TFTP server.
Time Server IP Address	IP address of the CMTS Time of Day (TOD) server.
Config File Name	Name of the configuration file that is downloaded from the TFTP server to provide the Cisco CVA120 Series Cable Voice Adapter with operational parameters.
Time Zone Offset	Correction received from the DHCP server to synchronize the Cisco CVA120 Series Cable Voice Adapter's time clock with the CMTS.

show controllers cable-modem phy

To display the contents of the registers used in the downstream physical hardware of the Cisco CVA120 Series Cable Voice Adapter, use the show controllers cable-modem phy privileged EXEC command.

To understand the output from this command, consult the Broadcom specifications for the BCM3116 and BCM3037 chips.

show controllers cable-modem qos

To display detailed information about the Quality of Service (QoS) configuration for the Cisco CVA120 Series Cable Voice Adapter, use the show controllers cable-modem qos privileged EXEC command.

This command displays the four possible stream queues, the SID associated with each queue (if the queue is currently in use), and whether the SID is the primary SID, a secondary (static) SID, or a dynamic (on demand) SID. The display also shows the packets and bytes that have been transmitted and received on each stream.

The following example displays the current QoS statistics for each of the router's four queues:

show controllers cable-modem tuner

To display the settings for the upstream and downstream tuners used by a Cisco CVA120 Series Cable Voice Adapter, use the show controllers cable-modem tuner privileged EXEC command.

Typical Cisco CVA120 Series Cable Voice Adapter tuner settings are displayed in the following example.

show controllers usb

To display high-level controller information for the USB interface on the Cisco CVA120 Series Cable Voice Adapter, use the show controllers usb privileged EXEC command.

The show controllers usb command displays the current state information for the USB interface and its controller.

The following example displays typical output for the show controllers usb 0 command:

show dhcp

To display the current Dynamic Host Configuration Protocol (DHCP) settings on point-to-point interfaces, use the show dhcp privileged EXEC command.

You can use this command on any point-to-point type of interface that uses DHCP for temporary IP address allocation.

show interfaces cable-modem

To display information about the Cisco CVA120 Series Cable Voice Adapter cable interface, use the show interfaces cable-modem command in either user EXEC mode or privileged EXEC mode.

When this command is entered without a keyword, general information about the cable interface is displayed.

Traffic passing through the cable access router interface is shown in the following example:

Table 19 show interfaces cable-modem Field Descriptions

Field	Description
cable-modem0 is up	Indicates that the interface is currently active. "Disabled" indicates the interface has received more than 5000 errors in one keepalive interval (10 seconds by default if keepalive is set); "administratively down" indicates the interface has been taken down by an administrator.
line protocol is up	Indicates that the software processes that handle the line protocol believe the interface is usable.
Hardware	Hardware type and MAC address.
Internet address	Internet address followed by the shorthand notation for the subnet mask.
MTU	Maximum Transmission Unit (equivalent of the maximum packet size) for the interface.
BW	Bandwidth of the interface in kilobits per second.
DLY	Delay of the interface in microseconds.
reliability	Reliability of the interface, expressed as a fraction of 255, calculated as an exponential average over a 5-minute period. (255/255 equals 100% reliability.)
tx load/rx load	Load on the interface caused by transmitting and receiving, expressed as a fraction of 255, calculated as an exponential average over a 5 minute period.
Encapsulation/loopback/keepalive	Encapsulation method assigned to the interface.
loopback	Indicates whether or not loopback is set.
keepalive	Indicates whether or not keepalives are set.
ARP type	Type of Address Resolution Protocol configured for the interface.
ARP Timeout	Number of hours, minutes, and seconds an ARP cache entry stays in the cache.
Last input/output	Number of hours, minutes, and seconds since the last packet was successfully received/transmitted by the interface.
output hang	Number of hours, minutes, and seconds since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "Last..." fields exceeds 24, the number of days and hours is displayed. If the field overflows, asterisks are printed.
Last clearing of "show interface" counters	Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared. *** indicates the elapsed time is too large to be displayed. 0:00:00 indicates the counters were cleared more than 231 milliseconds (and less than 232 milliseconds) ago.
Queueing strategy	Type of queueing strategy in effect on the interface.
Output queue/drops	Number of packets in the output queue followed by the size of the queue, and the number of packets dropped due to a full queue.
input queue/drops	Number of packets in the input queue followed by the size of the queue, and the number of packets dropped due to a full queue.
5 minute input rate 5 minute output rate	Average number of bits and packets received and transmitted per second in the last 5 minutes. If the interface is not in promiscuous mode, it senses network traffic that it sends and receives (rather than all network traffic). The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average is within two percent of the instantaneous rate of a uniform stream of traffic over that period.
packets input	Total number of error-free packets received by the system.
bytes input	Total number of bytes, including data and MAC encapsulation, in the error-free packets received by the system.
no buffer	Number of received packets discarded because there is no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernet networks and bursts of noise on serial lines are often responsible for no input buffer events.
Received broadcasts	Total number of broadcast or multicast packets received by the interface.
runts	Number of packets discarded because they were smaller than the medium's minimum packet size. For example, any Ethernet packet less than 64 bytes is considered a runt.
giants	Number of packets discarded because they were larger than the medium's maximum packet size. For example, any Ethernet packet larger than 1518 bytes is considered a giant.
throttles	Number of times the receiver on the port was disabled, possibly due to buffer or processor overload.
input errors	Includes runts, giants, no buffer, CRC, frame, overrun, and ignored counts. Other input-related errors can also cause the input errors count to be increased, and some datagrams can have more than one error; therefore, this sum might not balance with the sum of enumerated input error counts.
CRC	Number of cyclic redundancy checksums (CRCs) generated by the originating LAN station or far-end device that do not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station sending bad data.
frame	Number of packets received incorrectly, having a CRC error and a noninteger number of octets. On a LAN, this is usually the result of collisions or a malfunctioning Ethernet device.
overrun	Number of times the receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored	Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different from the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be increased.
abort	Number of packets whose receipt was aborted.
packets output	Total number of messages sent by the system.
bytes	Total number of bytes, including data and MAC encapsulation, sent by the system.
underruns	Number of times the transmitter has been running faster than the router can handle.
output errors	Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, because some datagrams might have more than one error, and other datagrams might have errors that do not fall into any of the specifically tabulated categories.
collisions	Number of messages retransmitted due to an Ethernet collision. This is usually the result of an overextended LAN (Ethernet or transceiver cable too long, more than two repeaters between stations, or too many cascaded multiport transceivers). A packet that collides is counted only once in output packets.
interface resets	Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds. On a serial line, this can be caused by a malfunctioning modem that is not supplying the transmit clock signal, or by a cable problem. If the system notices that the carrier detect line of a serial interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an interface is looped back or shut down.
output buffer failures	Number of times the output buffer has failed.
output buffers swapped out	Number of times the output buffer has been swapped out.

To display the number of packets and bytes of each protocol type passing through the cable access router interface, use the accounting option with the show interfaces cable-modem command:

Information about routing and bridging protocols and filtering on the cable access router interface is displayed in the following example:

Table 22 describes the software MAC address filter information for the cable access router interface.

show interfaces usb

To display configuration information about the USB interface, use the show interfaces usb privileged EXEC command.

Use the show interfaces usb privileged EXEC command to display configuration and status information for the USB interface.

The following is sample output from the show interfaces usb command for the Cisco CVA120 Series Cable Voice Adapter:

show voice port

To display configuration information about a specific voice port, use the show voice port privileged EXEC command.

This command applies to Voice over IP on the Cisco CVA120 Series Cable Voice Adapter.

Use this command to display configuration and voice interface card-specific information about a specific port.

The following is sample output from the show voice port command for the Cisco CVA120 Series Cable Voice Adapter:

voice-port

To enter the voice-port configuration mode, use the voice-port command in global configuration mode.

Use the voice-port global configuration command to switch to the voice-port configuration mode from the global configuration mode. Use the exit command to exit the voice-port configuration mode and return to the global configuration mode. See the Cisco IOS Release 12.1 Multiservice Applications Command Reference , available on CCO and the Documentation CD-ROM, for a list of subcommands that are supported by the voice-port global configuration command.

The following example accesses the voice-port configuration mode for port 0, the first voice port (labeled "V1+V2") on the Cisco CVA120 Series Cable Voice Adapter.

Debug Commands

This section documents the following debug commands, which are not normally needed to install or configure the Cisco CVA120 Series Cable Voice Adapter:

Additional debug commands are documented in the Cisco IOS Release 12.1 Debug Command Reference , available on CCO and the Documentation CD-ROM.

debug cable-modem bpkm

To display Baseline Privacy Interface (BPI) information, use the debug cable-modem bpkm command in privileged EXEC mode. To disable the debugging output, use the no form of this command.

This command should be used only while debugging cable modem operation. Displaying debugging messages consumes system resources, and turning on too many messages could negatively affect system performance.

The following example shows typical debug output when the headend does not have privacy enabled:

debug cable-modem bridge

The debug cable-modem bridge privileged EXEC command displays bridge filter processing information on a cable modem. To disable the debugging output, use the no form of this command.

: debug cable-modem bridge
: no debug cable-modem bridge

Syntax Description

This command has no keywords or arguments.

Defaults

The default is not to display any debugging messages.

Command History

Release Modification

11.3(4)NA

This command was introduced for the Cisco uBR904 cable access router.

12.0(4)XI1

Support was added for the Cisco uBR924 cable access router.

12.1(1)XD

Support was added for the Cisco uBR914 cable DSU.

12.1(3)XL

Support was added for the Cisco uBR905 cable access router.

12.1(5)XU2

Support was added for the Cisco CVA120 Series Cable Voice Adapter.

Usage Guidelines

When the interface is down, all bridge table entries learned on the Ethernet interface are set to discard because traffic is not bridged until the cable interface has completed initialization. After the interface (the line protocol) is completely up, bridge table entries learned on the Ethernet interface program the cable's MAC data filters. The cable MAC hardware filters out any received packets whose addresses are not in the filters. In this way, the cable interface only receives packets addressed to its own MAC address or an address it has learned on the Ethernet interface.

Examples

The following shows sample display output for the debug cable-modem bridge command.

cva120# debug cable-modem bridge

%LINEPROTO-5-UPDOWN: Line protocol on Interface cable-modem0, changed state to downshut

cm_tbridge_add_entry(): MAC not initialized, discarding entry: 00e0.fe7a.186fno shut

cm_tbridge_add_entry(): MAC not initialized, discarding entry: 00e0.fe7a.186f

%LINEPROTO-5-UPDOWN: Line protocol on Interface cable-modem0, changed state to up

cm_tbridge_add_entry(): Adding entry 00e0.fe7a.186f to filter 2

Related Commands

Command Description

debug cable-modem bpkm

Displays Baseline Privacy Interface (BPI) information.

debug cable-modem error

Displays debugging messages for the cable interface driver.

debug cable-modem interrupts

Displays information about cable modem interrupts.

debug cable-modem mac

Displays information about the cable modem MAC layer.

debug cable-modem map

Displays the timing of MAP and sync messages.

debug cable-modem error

The debug cable-modem error privileged EXEC command displays debugging messages for the cable interface driver. To disable the debugging output, use the no form of this command.

: debug cable-modem error
: no debug cable-modem error

Syntax Description

This command has no keywords or arguments.

Defaults

The default is not to display any debugging messages.

Command History

Usage Guidelines

This command displays detailed output about the sanity checking of received frame formats, the acquisition of downstream QAM/FEC lock, the receipt or nonreceipt of SYNC messages from the CMTS, reception errors, and bandwidth request failures.

Examples

The following shows sample display output for the debug cable-modem error command.

cva120# debug cable-modem error

*Mar  7 20:16:29: AcquireSync(): Update rate is 100 Hz

*Mar  7 20:16:30: 1st Sync acquired after 1100 ms.

*Mar  7 20:16:30: Recovery loop is locked (7/9)

*Mar  7 20:16:30: 2nd Sync acquired after 100 ms.

*Mar  7 20:16:30: Recovery loop is locked (10/15)

Related Commands

Command Description

debug cable-modem bpkm

Displays Baseline Privacy Interface (BPI) information.

debug cable-modem bridge

Displays bridge filter processing information.

debug cable-modem interrupts

Displays information about cable modem interrupts.

debug cable-modem mac

Displays information about the cable modem MAC layer.

debug cable-modem map

Displays the timing of MAP and sync messages.

debug cable-modem interrupts

The debug cable-modem interrupts privileged EXEC command displays information about cable modem interrupts. To disable the debugging output, use the no form of this command.

: debug cable-modem interrupts
: no debug cable-modem interrupts

Syntax Description

This command has no keywords or arguments.

Defaults

The default is not to display any debugging messages.

Command History

Usage Guidelines

Examples

The following shows sample debug output for cable modem interrupts.

cva120# debug cable-modem interrupts

*** bcm3220_rx_mac_msg_interrupt ***

*** bcm3220_rx_mac_msg_interrupt ***

### bcm3220_tx_interrupt ###

*** bcm3220_rx_mac_msg_interrupt ***

### bcm3220_tx_interrupt ###

*** bcm3220_rx_mac_msg_interrupt ***

### bcm3220_tx_interrupt ###

### bcm3220_tx_interrupt ###

### bcm3220_tx_interrupt ###

### bcm3220_tx_interrupt ###

Related Commands

Command Description

debug cable-modem bpkm

Displays Baseline Privacy Interface (BPI) information.

debug cable-modem bridge

Displays bridge filter processing information.

debug cable-modem error

Displays debugging messages for the cable interface driver.

debug cable-modem mac

Displays information about the cable modem MAC layer.

debug cable-modem map

Displays the timing of MAP and sync messages.

debug cable-modem mac

The debug cable-modem mac privileged EXEC command displays information about the cable modem MAC layer. To disable the debugging output, use the no form of this command.

: debug cable-modem mac {log [verbose] | messages}
: no debug cable-modem mac {log [verbose] | messages}

Syntax Description :

log

Real time MAC log display.

verbose

Displays periodic MAC layer events, such as ranging.

messages

MAC layer management messages.

Defaults

The default is not to display any debugging messages.

Command History

Release Modification

11.3(4)NA

This command was introduced for the Cisco uBR904 cable access router.

12.0(4)XI1

Support was added for the Cisco uBR924 cable access router.

12.1(1)XD

Support was added for the Cisco uBR914 cable DSU.

12.1(3)XL

Support was added for the Cisco uBR905 cable access router.

12.1(5)XU2

Support was added for the Cisco CVA120 Series Cable Voice Adapter.

Usage Guidelines

Of all the available debug cable modem commands, the most useful is debug cable-modem mac log.

Mac log messages are written to a circular log file even when debugging is not turned on. These messages include timestamps, events, and information pertinent to these events. Enter the debug cable-modem mac log command to view Mac log messages. If you want to view this information without entering debug mode, enter the show controllers cable-modem number mac log command. The same information is displayed by both commands.

If the Cisco CVA120 Series Cable Voice Adapter interface fails to come up or resets periodically, the Mac log will show what happened. For example, if an address is not obtained from the DHCP server, an error is logged, initialization starts over, and the cable modem scans for a downstream frequency. The debug cable-modem mac log command displays the log from oldest entry to newest entry.

After initial ranging is successful (dhcp_state has been reached), further RNG-REQ/RNG-RSP messages and watchdog timer entries are suppressed from output unless the verbose keyword is used. Note that CMAC_LOG_WATCHDOG_TIMER entries while in the maintenance_state are normal when using the verbose keyword.

Examples

Example 1

This example shows sample display output from the debug cable-modem mac log command. The fields of the output are the time since bootup, the log message, and in some cases a parameter that gives more detail about the log entry.

cva120# debug cable-modem mac log

*Mar  7 01:42:59: 528302.040 CMAC_LOG_LINK_DOWN                          

*Mar  7 01:42:59: 528302.042 CMAC_LOG_RESET_FROM_DRIVER                  

*Mar  7 01:42:59: 528302.044 CMAC_LOG_STATE_CHANGE                       wait_for_link_up_state

*Mar  7 01:42:59: 528302.046 CMAC_LOG_DRIVER_INIT_IDB_SHUTDOWN           0x08098D02

*Mar  7 01:42:59: 528302.048 CMAC_LOG_LINK_DOWN                          

*Mar  7 01:43:05: 528308.428 CMAC_LOG_DRIVER_INIT_IDB_RESET              0x08098E5E

*Mar  7 01:43:05: 528308.432 CMAC_LOG_LINK_DOWN                          

*Mar  7 01:43:05: 528308.434 CMAC_LOG_LINK_UP                            

*Mar  7 01:43:05: 528308.436 CMAC_LOG_STATE_CHANGE                       ds_channel_scanning_state

*Mar  7 01:43:05: 528308.440 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      88/453000000/855000000/6000000

*Mar  7 01:43:05: 528308.444 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      89/93000000/105000000/6000000

*Mar  7 01:43:05: 528308.448 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      90/111250000/117250000/6000000

*Mar  7 01:43:05: 528308.452 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      91/231012500/327012500/6000000

*Mar  7 01:43:05: 528308.456 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      92/333015000/333015000/6000000

*Mar  7 01:43:05: 528308.460 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      93/339012500/399012500/6000000

*Mar  7 01:43:05: 528308.462 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      94/405000000/447000000/6000000

*Mar  7 01:43:05: 528308.466 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      95/123015000/129015000/6000000

*Mar  7 01:43:05: 528308.470 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      96/135012500/135012500/6000000

*Mar  7 01:43:05: 528308.474 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      97/141000000/171000000/6000000

*Mar  7 01:43:05: 528308.478 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      98/219000000/225000000/6000000

*Mar  7 01:43:05: 528308.482 CMAC_LOG_WILL_SEARCH_DS_FREQUENCY_BAND      99/177000000/213000000/6000000

*Mar  7 01:43:05: 528308.486 CMAC_LOG_WILL_SEARCH_SAVED_DS_FREQUENCY     663000000

*Mar  7 01:43:05: 528308.488 CMAC_LOG_WILL_SEARCH_USER_DS_FREQUENCY      663000000

*Mar  7 01:43:07: 528310.292 CMAC_LOG_DS_64QAM_LOCK_ACQUIRED             663000000

.

.

.

528383.992 CMAC_LOG_STATE_CHANGE                       registration_state

528384.044 CMAC_LOG_REG_REQ_MSG_QUEUED                 

528384.050 CMAC_LOG_REG_REQ_TRANSMITTED                

528384.052 CMAC_LOG_REG_RSP_MSG_RCVD                   

528384.078 CMAC_LOG_COS_ASSIGNED_SID                   1/4

528384.102 CMAC_LOG_RNG_REQ_QUEUED                     4

528384.102 CMAC_LOG_REGISTRATION_OK                    

528384.102 CMAC_LOG_STATE_CHANGE                       establish_privacy_state

528384.102 CMAC_LOG_STATE_CHANGE                       maintenance_state

528388.444 CMAC_LOG_RNG_REQ_TRANSMITTED                

528388.444 CMAC_LOG_RNG_RSP_MSG_RCVD                   

528398.514 CMAC_LOG_RNG_REQ_TRANSMITTED                

528398.516 CMAC_LOG_RNG_RSP_MSG_RCVD                   

528408.584 CMAC_LOG_RNG_REQ_TRANSMITTED                

528408.586 CMAC_LOG_RNG_RSP_MSG_RCVD                   

528414.102 CMAC_LOG_WATCHDOG_TIMER                     

528418.654 CMAC_LOG_RNG_REQ_TRANSMITTED                

528418.656 CMAC_LOG_RNG_RSP_MSG_RCVD                   

528428.726 CMAC_LOG_RNG_REQ_TRANSMITTED                

528428.728 CMAC_LOG_RNG_RSP_MSG_RCVD                   

528438.796 CMAC_LOG_RNG_REQ_TRANSMITTED                

528438.798 CMAC_LOG_RNG_RSP_MSG_RCVD                   

528444.102 CMAC_LOG_WATCHDOG_TIMER                     

528444.492 CMAC_LOG_LINK_DOWN                          

528444.494 CMAC_LOG_RESET_FROM_DRIVER                  

528444.494 CMAC_LOG_STATE_CHANGE                       wait_for_link_up_state

528444.494 CMAC_LOG_DRIVER_INIT_IDB_SHUTDOWN           0x08098D02

528444.494 CMAC_LOG_LINK_DOWN                          

528474.494 CMAC_LOG_WATCHDOG_TIMER                     

528504.494 CMAC_LOG_WATCHDOG_TIMER                     

528534.494 CMAC_LOG_WATCHDOG_TIMER                     

0 events dropped due to lack of a chunk

Note The line "0 events dropped due to lack of a chunk" at the end of the display indicates that no log entries were discarded due to a temporary lack of memory. This means the log is accurate and reliable.

Example 2

The following example compares the output of the debug cable-modem mac log command with the debug cable-modem mac log verbose command. The verbose keyword displays periodic events such as ranging.

cva120# debug cable-modem mac log

Cable Modem mac log debugging is on

cva120#

cva120# debug cable-modem mac log verbose

Cable Modem mac log debugging is on (verbose)

cva120#

574623.810 CMAC_LOG_RNG_REQ_TRANSMITTED                

574623.812 CMAC_LOG_RNG_RSP_MSG_RCVD                   

574627.942 CMAC_LOG_WATCHDOG_TIMER                     

574633.880 CMAC_LOG_RNG_REQ_TRANSMITTED                

574633.884 CMAC_LOG_RNG_RSP_MSG_RCVD                   

574643.950 CMAC_LOG_RNG_REQ_TRANSMITTED                

574643.954 CMAC_LOG_RNG_RSP_MSG_RCVD                   

574654.022 CMAC_LOG_RNG_REQ_TRANSMITTED                

574654.024 CMAC_LOG_RNG_RSP_MSG_RCVD                   

574657.978 CMAC_LOG_WATCHDOG_TIMER                     

574664.094 CMAC_LOG_RNG_REQ_TRANSMITTED                

574664.096 CMAC_LOG_RNG_RSP_MSG_RCVD                   

574674.164 CMAC_LOG_RNG_REQ_TRANSMITTED                

574674.166 CMAC_LOG_RNG_RSP_MSG_RCVD                   

cva120# no debug cable-modem mac log verbose

Cable Modem mac log debugging is off

cva120#

574684.234 CMAC_LOG_RNG_REQ_TRANSMITTED                

574684.238 CMAC_LOG_RNG_RSP_MSG_RCVD                   

Example 3

The following example shows display output for the debug cable-modem mac messages command. This command causes received cable MAC management messages to be displayed in a verbose format. The messages that are displayed are shown below:

cva120# debug cable-modem mac messages?

  dynsrv   dynamic service mac messages

  map      map messages received

  reg-req  reg-req  messages transmitted

  reg-rsp  reg-rsp messages received

  rng-req  rng-req  messages transmitted

  rng-rsp  rng-rsp messages received

  sync     Sync messages received

  ucc-req  ucc-req messages received

  ucc-rsp  ucc-rsp messages transmitted

  ucd      UCD messages received

  <cr>

The dynsrv keyword displays Dynamic Service Add (DSA) or Dynamic Service Delete (DSD) messages during the off-hook/on-hook transitions of a phone connected to the Cisco CVA120 Series Cable Voice Adapter.

In addition, transmitted REG-REQs are displayed in hex dump format. The output from this command is very verbose and is usually not needed for normal interface debugging. The command is most useful when attempting to attach a Cisco CVA120 Series Cable Voice Adapter to a CMTS that is not DOCSIS-qualified.

For a description of the displayed fields of each message, refer to the DOCSIS Radio Frequency Interface Specification, v1.0 (SP-RFI-I04-980724).

cva120# debug cable-modem mac messages

*Mar  7 01:44:06: 

*Mar  7 01:44:06: UCD MESSAGE

*Mar  7 01:44:06: -----------

*Mar  7 01:44:06:   FRAME HEADER

*Mar  7 01:44:06:     FC                        - 0xC2 == MAC Management

*Mar  7 01:44:06:     MAC_PARM                  - 0x00

*Mar  7 01:44:06:     LEN                       - 0xD3

*Mar  7 01:44:06:   MAC MANAGEMENT MESSAGE HEADER

*Mar  7 01:44:06:     DA                        - 01E0.2F00.0001

*Mar  7 01:44:06:     SA                        - 00E0.1EA5.BB60

*Mar  7 01:44:06:     msg LEN                   - C1  

*Mar  7 01:44:06:     DSAP                      - 0

*Mar  7 01:44:06:     SSAP                      - 0

*Mar  7 01:44:06:     control                   - 03

*Mar  7 01:44:06:     version                   - 01

*Mar  7 01:44:06:     type                      - 02 == UCD

*Mar  7 01:44:06:     RSVD                      - 0

*Mar  7 01:44:06:   US Channel ID               - 1

*Mar  7 01:44:06:   Configuration Change Count  - 4

*Mar  7 01:44:06:   Mini-Slot Size              - 8

*Mar  7 01:44:06:   DS Channel ID               - 1

*Mar  7 01:44:06:   Symbol Rate                 - 8

*Mar  7 01:44:06:   Frequency                   - 20000000

*Mar  7 01:44:06:   Preamble Pattern            - CC CC CC CC CC CC CC CC CC CC CC 0D 0D 

*Mar  7 01:44:06:   Burst Descriptor 0

*Mar  7 01:44:06:     Interval Usage Code       - 1

*Mar  7 01:44:06:     Modulation Type           - 1 == QPSK

*Mar  7 01:44:06:     Differential Encoding     - 2 == OFF

*Mar  7 01:44:06:     Preamble Length           - 64

*Mar  7 01:44:06:     Preamble Value Offset     - 56

*Mar  7 01:44:06:     FEC Error Correction      - 0

*Mar  7 01:44:06:     FEC Codeword Info Bytes   - 16

*Mar  7 01:44:06:     Scrambler Seed            - 0x0152

*Mar  7 01:44:06:     Maximum Burst Size        - 1

*Mar  7 01:44:06:     Guard Time Size           - 8

*Mar  7 01:44:06:     Last Codeword Length      - 1 == FIXED

*Mar  7 01:44:06:     Scrambler on/off          - 1 == ON

*Mar  7 01:44:06:   Burst Descriptor 1

*Mar  7 01:44:06:     Interval Usage Code       - 3

*Mar  7 01:44:06:     Modulation Type           - 1 == QPSK

*Mar  7 01:44:06:     Differential Encoding     - 2 == OFF

*Mar  7 01:44:06:     Preamble Length           - 128

*Mar  7 01:44:06:     Preamble Value Offset     - 0

*Mar  7 01:44:06:     FEC Error Correction      - 5

*Mar  7 01:44:06:     FEC Codeword Info Bytes   - 34

*Mar  7 01:44:06:     Scrambler Seed            - 0x0152

*Mar  7 01:44:06:     Maximum Burst Size        - 0

*Mar  7 01:44:06:     Guard Time Size           - 48

*Mar  7 01:44:06:     Last Codeword Length      - 1 == FIXED

*Mar  7 01:44:06:     Scrambler on/off          - 1 == ON

*Mar  7 01:44:06:   Burst Descriptor 2

*Mar  7 01:44:06:     Interval Usage Code       - 4

*Mar  7 01:44:06:     Modulation Type           - 1 == QPSK

*Mar  7 01:44:06:     Differential Encoding     - 2 == OFF

*Mar  7 01:44:06:     Preamble Length           - 128

*Mar  7 01:44:06:     Preamble Value Offset     - 0

*Mar  7 01:44:06:     FEC Error Correction      - 5

*Mar  7 01:44:06:     FEC Codeword Info Bytes   - 34

*Mar  7 01:44:06:     Scrambler Seed            - 0x0152

*Mar  7 01:44:06:     Maximum Burst Size        - 0

*Mar  7 01:44:06:     Guard Time Size           - 48

*Mar  7 01:44:06:     Last Codeword Length      - 1 == FIXED

*Mar  7 01:44:06:     Scrambler on/off          - 1 == ON

*Mar  7 01:44:06:   Burst Descriptor 3

*Mar  7 01:44:06:     Interval Usage Code       - 5

*Mar  7 01:44:06:     Modulation Type           - 1 == QPSK

*Mar  7 01:44:06:     Differential Encoding     - 2 == OFF

*Mar  7 01:44:06:     Preamble Length           - 72

*Mar  7 01:44:06:     Preamble Value Offset     - 48

*Mar  7 01:44:06:     FEC Error Correction      - 5

*Mar  7 01:44:06:     FEC Codeword Info Bytes   - 75

*Mar  7 01:44:06:     Scrambler Seed            - 0x0152

*Mar  7 01:44:06:     Maximum Burst Size        - 0

*Mar  7 01:44:06:     Guard Time Size           - 8

*Mar  7 01:44:06:     Last Codeword Length      - 1 == FIXED

*Mar  7 01:44:06:     Scrambler on/off          - 1 == ON

*Mar  7 01:44:06: 

*Mar  7 01:44:06: 

*Mar  7 01:44:06: MAP MESSAGE

*Mar  7 01:44:06: -----------

*Mar  7 01:44:06:   FRAME HEADER

*Mar  7 01:44:06:     FC                        - 0xC3 == MAC Mement with Extended Header

*Mar  7 01:44:06:     MAC_PARM                  - 0x02

*Mar  7 01:44:06:     LEN                       - 0x42

*Mar  7 01:44:06:     EHDR                      - 0x00 0x00 

*Mar  7 01:44:06:   MAC MANAGEMENT MESSAGE HEADER

*Mar  7 01:44:06:     DA                        - 01E0.2F00.0001

.

*Mar  7 01:44:17: RNG-RSP MESSAGE

*Mar  7 01:44:17: ---------------

*Mar  7 01:44:17:   FRAME HEADER

*Mar  7 01:44:17:     FC                        - 0xC2 == MAC Management

*Mar  7 01:44:17:     MAC_PARM                  - 0x00

*Mar  7 01:44:17:     LEN                       - 0x2B

*Mar  7 01:44:17:   MAC MANAGEMENT MESSAGE HEADER

*Mar  7 01:44:17:     DA                        - 00F0.1EB2.BB61

.

*Mar  7 01:44:20: REG-REQ MESSAGE

*Mar  7 01:44:20: ---------------

*Mar  7 01:44:20: C20000A5 000000E0  1EA5BB60 00F01EB2

*Mar  7 01:44:20: BB610093 00000301  06000004 03010104

*Mar  7 01:44:20: 1F010101 0204003D  09000304 001E8480

*Mar  7 01:44:20: 04010705 04000186  A0060200 0C070101

*Mar  7 01:44:20: 080300F0 1E112A01  04000000 0A020400

*Mar  7 01:44:20: 00000A03 04000002  58040400 00000105

*Mar  7 01:44:20: 04000000 01060400  00025807 04000000

*Mar  7 01:44:20: 3C2B0563 6973636F  06105E4F C908C655

*Mar  7 01:44:20: 61086FD5 5C9D756F  7B730710 434D5453

*Mar  7 01:44:20: 204D4943 202D2D2D  2D2D2D2D 0C040000

*Mar  7 01:44:20: 00000503 010100

*Mar  7 01:44:20: 

*Mar  7 01:44:20: 

*Mar  7 01:44:20: REG-RSP MESSAGE

*Mar  7 01:44:20: ---------------

*Mar  7 01:44:20:   FRAME HEADER

*Mar  7 01:44:20:     FC                        - 0xC2 == MAC Management

*Mar  7 01:44:20:     MAC_PARM                  - 0x00

*Mar  7 01:44:20:     LEN                       - 0x29

*Mar  7 01:44:20:   MAC MANAGEMENT MESSAGE HEADER

*Mar  7 01:44:20:     DA                        - 00F0.1EB2.BB61

Related Commands

Command Description

debug cable-modem bpkm

Displays Baseline Privacy Interface (BPI) information.

debug cable-modem bridge

Displays bridge filter processing information.

debug cable-modem error

Displays sdebugging messages for the cable interface driver.

debug cable-modem interrupts

Display information about cable modem interrupts.

debug cable-modem map

Displays the timing of MAP and sync messages.

debug cable-modem mac messages dynsrv

To display debug messages for the dynamic service MAC-layer messages that are generated when voice calls are made using the dynamic SID feature, use the debug cable-modem mac messages dynsrv privileged EXEC command. To disable the debugging output, use the no form of this command.

: debug cable-modem mac messages dynsrv
: no debug cable-modem mac messages dynsrv

Syntax Description

This command has no keywords or arguments.

Defaults

No default behavior or values.

Command History

Release Modification

12.0(7)XR and 12.1(1)T

This command was introduced for the Cisco uBR924 cable access router.

12.1(1)XD

Support was added for the Cisco uBR914 cable DSU.

12.1(3)XL

Support was added for the Cisco uBR905 cable access router.

12.1(5)XU2

Support was added for the Cisco CVA120 Series Cable Voice Adapter.

Usage Guidelines

This command begins the display of debug messages that show the dynamic service MAC messages that are generated when a voice call is made using the dynamic SID feature. Dynamic SIDs use the following DOCSIS MAC-layer messages to create a new SID when a voice call is made, and to delete it when the call is over:

DSA-REQ—Dynamic Service Addition Request, sent to establish a new service flow.
DSA-RSP—Dynamic Service Addition Response, sent in reply to DSA-REQ to confirm or deny the new service flow.
DSA-ACK—Dynamic Service Addition Acknowledge, sent in reply to DSA-RSP to acknowledge the creation of the service flow.
DSD-REQ—Dynamic Service Deletion Request, sent to delete an existing service flow when it is no longer needed (for example, when a voice call has terminated).
DSD-RSP—Dynamic Service Deletion Response, sent in response to DSD-REQ to delete an existing service flow.

Note Dynamic Services are described in the DOCSIS 1.1 specification (SP-RFIv1.1-I03-991105 or later revision).

Examples

The following example enables the display of debug messages related to dynamic service operations:

cva120# debug cable-modem mac messages dynsrv 

cva120# 

The following example turns off the display of debug messages related to dynamic service operations:

cva120# no debug cable-modem mac messages dynsrv 

cva120# 

The following are examples of the types of debug messages that are displayed when a voice call is made. This example shows that dynamic SID 52 is created for this particular call.

DSA-REQ TLV's: 

--------------

US Flow Scheduler(24):

 Unsolicited Grant Size               - 19:2:89

 Nominal Grant Interval               - 20:4:20000

Created New Dynamic Service State, Transaction_id = 3

DSA-REQ MESSAGE TLVS

--------------------

C2000026 00010010  07DF6854 00507366

23270014 00000301  0F000003 180A1302

00591404 00004E20  

   597.721 CMAC_LOG_DSA_REQ_MESSAGE_EVENT 

DSA-REQ MESSAGE

---------------

  FRAME HEADER

    FC                        - 0xC2 == MAC Management

    MAC_PARM                  - 0x00

    LEN                       - 0x26

  MAC MANAGEMENT MESSAGE HEADER

    DA                        - 0010.abcd.ef00

    SA                        - 0050.abcd.ef00

    msg LEN                   - 14  

    DSAP                      - 0

    SSAP                      - 0

    control                   - 03

    version                   - 01

    type                      - 0F == DSA-REQ

    RSVD                      - 0

  Transaction ID              - 3

   597.725 CMAC_LOG_DSA_RSP_MSG_RCVD 

DSA-RSP MESSAGE

---------------

  FRAME HEADER

    FC                        - 0xC2 == MAC Management

    MAC_PARM                  - 0x00

    LEN                       - 0x26

  MAC MANAGEMENT MESSAGE HEADER

    DA                        - 0050.abcd.ef00

    SA                        - 0010.abcd.ef00

    msg LEN                   - 14  

    DSAP                      - 0

    SSAP                      - 0

    control                   - 03

    version                   - 01

    type                      - 10 == DSA-RSP

    RSVD                      - 0

  Transaction ID              - 3

  Response                    - 0 == DSA-RSP-OK

  SID                         - 52

Adding sid = 52 to sid_index = 1

   597.729 CMAC_LOG_QOS_ADD_FLOW_SID                   52

Related Commands

Command Description

debug cable-modem mac messages

Displays debug messages for other types of MAC-layer messages, including MAP messages, upstream request messages, and sync messages.

show controllers cable-modem qos

Displays current statistics for each primary, secondary, and dynamic SIDs.

debug cable-modem map

The debug cable-modem map privileged EXEC command displays the timing from MAP messages to sync messages and the timing between MAP messages. To disable the debugging output, use the no form of this command.

: debug cable-modem map
: no debug cable-modem map

Syntax Description

This command has no keywords or arguments.

Defaults

The default is not to display any debugging messages.

Command History

Usage Guidelines

Examples

The following shows display output for the debug cable-modem map command.

cva120# debug cable-modem map

Cable Modem MAP debugging is on

cva120#

*Mar  7 20:12:08: 595322.942: Min MAP to sync=72

*Mar  7 20:12:08: 595322.944: Max map to map time is 40

*Mar  7 20:12:08: 595322.982: Min MAP to sync=63

*Mar  7 20:12:08: 595323.110: Max map to map time is 41

*Mar  7 20:12:08: 595323.262: Min MAP to sync=59

*Mar  7 20:12:08: 595323.440: Max map to map time is 46

*Mar  7 20:12:09: 595323.872: Min MAP to sync=58

Related Commands

Command Description

debug cable-modem bpkm

Displays Baseline Privacy Interface (BPI) information.

debug cable-modem bridge

Displays bridge filter processing information.

debug cable-modem error

Displays debugging messages for the cable interface driver.

debug cable-modem interrupts

Displays information about cable modem interrupts.

debug cable-modem mac

Displays information about the cable modem MAC layer.

debug usb

The debug usb privileged EXEC command displays debugging messages about the USB interface. To disable the debugging output, use the no form of this command.

: debug usb { rx | tx }
: no debug usb { rx | tx }

Syntax Description

rx

Displays receive packet events.

tx

Displays transmit packet events.

Defaults

The default is not to display any debugging messages.

Command History

Release Modification

12.1(5)XU2

This command was introduced for the Cisco CVA120 Series Cable Voice Adapter.

Usage Guidelines

This command should be used only while debugging cable modem operation. Displaying debugging messages consumes system resources. Turning on too many messages could negatively affect system performance.

Examples

The following shows display output for the debug usb command.

cva120# debug usb rx

USB Rx debugging is on

cva120# debug usb tx

USB Tx debugging is on

Related Commands

Command Description

debug cable-modem bpkm

Displays Baseline Privacy Interface (BPI) information.

debug cable-modem bridge

Displays bridge filter processing information.

debug cable-modem error

Displays debugging messages for the cable interface driver.

debug cable-modem interrupts

Displays information about cable modem interrupts.

debug cable-modem mac

Displays information about the cable modem MAC layer.

Glossary

To fully understand the content of this guide, you should be familiar with the acronyms and terms listed in this section. These terms are specific to the operation of a data cable network; more general networking acronyms and terms can be found in Internetworking Terms and Acronyms, available on CCO and the Documentation CD-ROM.

3DES—Triple Data Encryption Standard.

ASIC—Application Specific Integrated Circuit.

BPI—Baseline Privacy Interface.

BPI+ —Extension to the initial BPI standard with improved authentication and encryption.

CM—Cable modem.

CMTS—Cable Modem Termination System (headend).

CoS—Class of service.

CPE—Customer Premises Equipment.

DES—Data Encryption Standard.

DOCSIS 1.0—Data Over Cable Service Interface Specification.

DOCSIS 1.0+ —Extension of the DOCSIS 1.0 standard with features that support quality of service (QoS) options to offer better than best effort, low latency, and low jitter services.

downstream—Transmission of traffic from the CMTS (headend) to the CM (cable modem).

IPSec—IP network security.

Kbps—Kilobits per second.

MAC—Media Access Control.

Mbps—Megabits per second.

modem—modulator/demodulator.

MSO—Multiple Systems Operator.

NIU/STB—Network Interface Unit/Set-Top Box.

PPS—Packets per second.

QAM—Quadrature Amplitude Modulation.

QoS—Quality of service.

QPSK—Quadrature Phase Shift Keying.

RF—Radio frequency.

SID—Service Identifier (DOCSIS MAC-level service flow identifier)

SM—Subscriber Modem or Spectrum Manager.

uBR—Universal broadband router.

upstream—Transmission of traffic from CM (cable modem) to the CMTS (headend).

VoIP—Voice over IP.

Command	Description
show controllers cable-modem	Displays high-level controller information about a Cisco CVA120 Series Cable Voice Adapter.
show controllers cable-modem bpkm	Displays information about the baseline privacy key management exchange between the Cisco CVA120 Series Cable Voice Adapter and the CMTS.
show controllers cable-modem des	Displays information about the Data Encryption Standard (DES) engine registers.
show controllers cable-modem filters	Displays the registers in the MAC hardware that are used for filtering received frames.
show controllers cable-modem lookup-table	Displays the mini-slot lookup table inside a Cisco CVA120 Series Cable Voice Adapter.
show controllers cable-modem mac	Displays detailed MAC-layer information for a Cisco CVA120 Series Cable Voice Adapter.
show controllers cable-modem tuner	Displays the settings for the upstream and downstream tuners used by a Cisco CVA120 Series Cable Voice Adapter.

Command	Description
show controllers cable-modem	Displays high-level controller information about a Cisco CVA120 Series Cable Voice Adapter.
show controllers cable-modem bpkm	Displays information about the baseline privacy key management exchange between the Cisco CVA120 Series Cable Voice Adapter and the CMTS.
show controllers cable-modem des	Displays information about the Data Encryption Standard (DES) engine registers.
show controllers cable-modem filters	Displays the registers in the MAC hardware that are used for filtering received frames.
show controllers cable-modem lookup-table	Displays the mini-slot lookup table inside a Cisco CVA120 Series Cable Voice Adapter.
show controllers cable-modem mac	Displays detailed MAC-layer information for a Cisco CVA120 Series Cable Voice Adapter.
show controllers cable-modem phy	Displays the contents of the registers used in the downstream physical hardware of the Cisco CVA120 Series Cable Voice Adapter.

Table of Contents

Cisco CVA120 Series Cable Voice Adapter Features

Part Number: OL-0805-02June 11, 2001Cisco IOS Release 12.1(5)XU2

Feature Overview

Cisco CVA120 Series Cable Voice Adapter Models

Bridging Operations

Voice Operations

Voice Handling

Quality of Service Support

H.323v2 Protocol

SGCP and MGCP Protocol Stack

IP Routing Operations

Dynamic Host Configuration Protocol Proxy Support

Routing Information Protocol Version 2

Upgrading the Software Image

Downloading the Cisco IOS Software Image

Downloading the Cisco IOS Configuration File

Upgrading the ROM Monitor Software

Benefits

Voice Over IP

USB and Ethernet Ports

Primary Line Support

Plug-and-Play Registration

Switched Interface

Investment Protection for the MSO

Restrictions

Related Documents

Cisco CVA120 Series Cable Voice Adapter

CMTS Hardware Installation Publications

Cisco IOS Publications

Configuration Editor and Network Management Publications

Subscriber Publications

Supported Platforms

Supported Standards, MIBs, and RFCs

Standards

MIBs

RFCs

Prerequisites

Site Requirements

Environmental

Power

Cabling

Configuration Tasks

DHCP Server Configuration

DOCSIS Configuration File

Cisco IOS Configuration File and Commands

Configuration Examples

DOCSIS-Compliant IP Bridging (Data-Only Mode)

Configuring for Routing Mode

To use RIPv2:

Configuring Routing with DHCP Server

NAT/PAT Configuration

H.323v2 Static Bridging Configuration

To configure incoming calls on the voice ports:

Repeat this sequence for each voice port.

Repeat through Step 12 for each possible outgoing destination:

H.323v2 Dynamic Mapping Configuration

To configure incoming calls on the voice ports:

Repeat this sequence for each voice port.

Configure the possible outgoing destinations:

Repeat through Step 10 for each possible outgoing destination:

SGCP Configuration

To configure incoming calls on the voice ports:

Repeat this sequence for each voice port.

MGCP Configuration

To configure incoming calls on the voice ports:

Repeat this sequence for each voice port.

Command Reference

cable dhcp-proxy

cable-modem compliant bridge

cable-modem voip clock-internal

dtmf-relay

h323-gateway voip bind srcaddr

interface cable-modem

interface usb

ip address docsis

ip http cable-monitor

ping docsis

show bridge cable-modem

show controllers cable-modem

Part Number: OL-0805-02
June 11, 2001
Cisco IOS Release 12.1(5)XU2