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Table of Contents

Octal-Port G.SHDSL SHTU-C Line Card

Octal-Port G.SHDSL SHTU-C Line Card

This feature module describes Cisco IOS 12.1(7)DA support for the Octal-Port G.SHDSL SHTU-C Line Card (8xG.SHDSL line card). It includes background information on the new G.SHDSL standard and new and modified IOS commands.

This document includes the following sections:

Feature Overview

This feature supports the Cisco 8xG.SHDSL line card. The 8xG.SHDSL line card transceivers provide duplex transmission over mixed gauge two-wire twisted metallic pairs.The 8xG.SHDSL line card transceivers are capable of supporting multiple symmetric data rates ranging from 72 kbps to 2312 kbps using Trellis Coded Pulse Amplitude Modulation (TC-PAM) line coding.

Benefits

This section describes the benefits offered by the 8xG.SHDSL line card.

Table 1 compares the Cisco 8xG.SHDSL line card to the technologies with which it is designed to compete.


Table 1: Feature/Performance Comparison Between G.SHDSL and Other Technologies
G.SHDSL SDSL HDSL2 HDSL T1 E1 IDSL/ISDN
Standardized

Yes

No

Yes

Yes

Yes

Yes

No

ATM Framing

Yes

Yes

No

No

No

No

No

T1 Framing

No

No

Yes

Yes

Yes

No

No

E1 Framing

No

No

No

No

No

Yes

No

Super Reach

Yes

No

No

No

No

No

No

High Density

Yes

Yes

No

No

No

No

Yes

Rate Adaptive

No

No

No

No

No

No

No

Repeatable

Yes1

No

No

Yes

Yes

No

Yes

G.hs

Yes

No

No

No

No

No

No

1Currently, no SHDSL repeaters have been developed.

Multiple Symmetric Line Rates

The 8xG.SHDSL line card supports multiple line rates ranging from 72 kbps to 2312 kbps.

Improved Reach

G.SHDSL TC-PAM line code improves reach over competing technologies.


Note   Cisco will extend the 8xG.SHDSL line card reach as SHDSL repeaters are developed and verified as interoperable.

Spectral Compatibility

Spectral Compatibility is an important topic that is being addressed by both European and North American standards bodies. The current Draft Spectral Management Standard defines seven spectral classes that are used to police binder groups and guarantee maintained spectral compatibility of multiple binder groups. Cisco solutions meet the guidelines of spectral compatibility as defined in the Draft Spectral Management Standard.

Low Power Consumption

Silicon vendors have developed subwatt chipsets that enable port densities higher than technologies such as SDSL and IDSL.

Restrictions

The NI-2 has an upstream throughput limit of 5 Mbps on even or odd ports for each line card. For example, ports 2, 4, 6, and 8 on an 8xG.SHDSL line card are only capable of supporting 5 Mbps upstream. This restriction prevents all ports on a line card from running at a full rate of 2312 kbps. An alarm is issued when more than 5 Mbps are provisioned for the even or odd ports.

Related Features and Technologies

The 8xG.SHDSL line card should be used in conjunction with the Cisco 828 G.SHDSL router or the Cisco SOHO 78 G.SHDSL router.

Related Documents

Hardware Documents

A complete list of all DSL hardware product related documentation is available on the World Wide Web at http://www.cisco.com/univercd/cc/td/doc/product/dsl_prod/index.htm.

Software Documents

A complete list of all DSL IOS software product related documentation is available on the World Wide Web at http://www.cisco.com/univercd/cc/td/doc/product/dsl_prod/ios_dsl/index.htm.

In the ATM software product related documentation, look for information pertaining to the Cisco LightStream 1010, which uses the same software base as the NI-2 DSL systems. This documentation is available on the World Wide Web at http://www.cisco.com/univercd/cc/td/doc/product/atm/index.htm.

Supported Platforms

You can install and operate the 8xG.SHDSL line card in the following DSLAMs:

The 8xG.SHDSL line card must be used in conjunction with the Cisco 828 G.SHDSL router or the Cisco SOHO 78 G.SHDSL router.

Supported Standards, MIBs, and RFCs

Standards

The following standards are supported by the 8xG.SHDSL line card:

MIBs

Cisco derived MIBS

To obtain lists of MIBs supported by platform and Cisco IOS release, and to download MIB modules, go to the Cisco MIB web site on Cisco Connection Online (CCO) at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.

Standard MIBS are defined in RFCs 1695 and 2662.

RFCs

The following RFCs are supported by the 8xG.SHDSL line card:

Prerequisites

Have one of the following DSLAM platforms with IOS 12.1(7)DA or later installed:

The Cisco 828 G.SHDSL router or the Cisco SOHO 78 G.SHDSL router must be installed at the customer premises.

Configuration Tasks

The following sections explain how to configure the 8xG.SHDSL line card. Each task in the list indicates if the task is optional or required.

Preprovisioning the 8xG.SHDSL Line Card

Starting at the global configuration prompt, use the following commands to pre-provision a slot for use with the 8xG.SHDSL line card:

Command Purpose

Step 1 

DSLAM(config)#slot 1 STUC-8-TCPAM

Associate the 8xG.SHDSL line card with the specified slot.

Step 2 

DSLAM(config)# dsl-profile austin

Create and name the DSL profile.

Step 3 

DSLAM(cfg-dsl-prof)# exit

Return to the global configuration prompt.

Step 4 

DSLAM(config)# interface atm1/1

Enter interface configuration mode on the port where you will associate the austin dsl profile.

Repeat this process on each port that you wish to associate with a dsl profile.

Step 5 

DSLAM(config-if)# dsl profile austin

Associate the dsl profile austin with atm interface 1/1.

Step 6 

DSLAM(config-if)# exit

Return to the global configuration prompt.

Step 7 

DSLAM(config)# dsl-profile austin

Enter DSL profile configuration mode.

Step 8 

DSLAM(cfg-dsl-prof)# shdsl bitrate 2312

Configure a bit rate of 2312 kbps.

Step 9 

DSLAM(cfg-dsl-prof)#shdsl margin min 0 DSLAM(cfg-dsl-prof)#shdsl margin target 3 DSLAM(cfg-dsl-prof)#shdsl margin threshold 0

Configure signal-to-noise ratio (SNR) margin values for the DSL profile.

Note Cisco suggests that you use the default configuration shown in this step.

Step 10 

DSLAM(cfg-dsl-prof)# shdsl masktype symmetric

Set the DSL mask type as symmetric.

Note In future software releases, asymmetric masks will be supported for certain bit rates.

Step 11 

DSLAM(cfg-dsl-prof)# shdsl annex a

Or

DSLAM(cfg-dsl-prof)# shdsl annex b

Configure SHDSL annex type A.


Configure SHDSL annex type B.


Tips After you complete these steps, insert the 8xG.SHDSL line card to activate the card with your preprovisioned configuration.

Verifying the Preprovisioned Slot

Use the show running-configuration command to verify that you have preprovisioned the slot correctly.

Creating and Associating a DSL Profile with Each Port

Before starting this configuration task, install the 8xG.SHDSL line card. Refer to the Octal-Port G.SHDSL SHTU-C Line Card FRU Installation and Replacement Notes for information on installing the 8xG.SHDSL line card.

Starting at the global configuration prompt, use the following procedure to associate a DSL profile with a port:

Command Purpose

Step 1 

DSLAM(config)# dsl-profile austin

Create and name the DSL profile.

Step 2 

DSLAM(cfg-dsl-prof)# exit

Return to the global configuration prompt.

Step 3 

DSLAM(config)# interface atm1/1

Enter interface configuration mode on the port where you will associate the austin dsl profile.

Repeat this process on each port that you wish to associate with a dsl profile.

Step 4 

DSLAM(config-if)# dsl profile austin

Associate the dsl profile austin with atm interface 1/1.

Verifying the DSL Profiles

Use the show dsl profile profile-name command to verify that a DSL profile is attached to a port. Use the show running-config command to verify that the DSL profile has been associated with a port.


Tips If no DSL profile appears in the show running-configuration command output, the default DSL profile is enabled. See the "Command Reference" section for the default configuration values.

Modifying the DSL Profile

Starting at the global configuration prompt, use the following procedure to modify the default bit rate, mask type, annex type, and signal to noise ratio parameters in your DSL profile:

Command Purpose

Step 1 

DSLAM(config)# dsl-profile austin

Enter DSL profile configuration mode.

Step 2 

DSLAM(cfg-dsl-prof)# shdsl bitrate 2312

Configure a bit rate of 2312 kbps.

Step 3 

DSLAM(cfg-dsl-prof)#shdsl margin min 0 DSLAM(cfg-dsl-prof)#shdsl margin target 3 DSLAM(cfg-dsl-prof)#shdsl margin threshold 0

Configure SNR margin values for the DSL profile.

Note Cisco suggests that you use the default configuration shown in this step.

Step 4 

DSLAM(cfg-dsl-prof)# shdsl masktype symmetric

Set the DSL mask type as symmetric.

Note In future software releases, asymmetric masks will be supported for certain bit rates.

Step 5 

DSLAM(cfg-dsl-prof)# shdsl annex a

Or

DSLAM(cfg-dsl-prof)# shdsl annex b

Configure SHDSL annex type A.


Configure SHDSL annex type B.

Monitoring and Maintaining the 8xG.SHDSL Line Card

Use the following commands to monitor and maintain the 8xG.SHDSL line card:

Command Purpose
DSLAM# show dsl status

Use the show dsl status command to display basic information about the DSL link, including port status and cards detected.

DSLAM# show dsl status shdsl

Use the show dsl status shdsl command to determine the administrative and operational status of each SHDSL port. Nothing is displayed for slots that are empty and unprovisioned. This command also provides information on SNR, header error control (HEC) errors, line rates, receiver gain, and SHDSL cards detected.

DSLAM# show facility-alarm status

Use the show facility-alarm status command to display all of the current major and minor alarms and the user-configurable alarm thresholds for temperature. After an alarm condition is indicated (by LEDs or bells), the show facility-alarm status command can be used to determine the cause of the alarm.

DSLAM# show hardware

Use the show hardware command to show information on each of the slots in your chassis. It tells whether a line card and fan trays are present.

DSLAM# show dsl interface atm slot/port

Use the show dsl interface command to view the status or results of a line test or to get information on port status, alarms, configured and actual transmission rates, and transmission errors.

Configuration Examples

The following configuration example describes how to configure SHDSL parameters in Cisco IOS 12.1(7)DA and above.

dsl-profile austin shdsl margin threshold 10 shdsl margin min 2 shdsl set bitrate 2312 masktype symmetric annex a

Command Reference

This section documents new or modified commands.

Many of the commands in this section discuss the configuration of SHDSL bit rates, annex types, and mask types. Use Table 2 to configure valid combinations of shdsl bit rates, shdsl mask types, and shdsl annex types.


Table 2: Supported Combinations of Bit Rate, Mask Type, and Annex Type
Bit rate Mask type Annex type

72

Symmetric

A or B

136

Symmetric

A or B

200

Symmetric

A or B

264

Symmetric

A or B

392

Symmetric

A or B

520

Symmetric

A or B

776

Symmetric

A or B

1032

Symmetric

A or B

1160

Symmetric

A or B

1544

Symmetric

A or B

2056

Symmetric

A or B

2312

Symmetric

A or B

shdsl annex

To configure the shdsl annex type, use the shdsl annex DSL profile configuration command. To disable, use the no form of this command.

shdsl annex {a | b}

no shdsl annex {a | b}

Syntax Description

a

Configures annex type a on the selected DSL profile.

b

Configures annex type b on the selected DSL profile.

Defaults

The default setting for the shdsl annex command is Annex A.

Command Modes

DSL profile configuration.

Command History

Release Modification

12.1(7)DA

This command was introduced.

Usage Guidelines

Use Annex A in North American network implementations. Annex B is appropriate for European SHDSL implementations.

Examples

The following example describes how to configure SHDSL Annex B:

dsl-profile austin  shdsl annex b

Related Commands

Command Description

shdsl set bitrate rate masktype symmetric annex {a | b}

Configures the bit rate, mask type, and annex type on a DSL profile.

shdsl margin {min dB | threshold dB | target dB}

Configures margin values, in decibels, on a DSL profile.

shdsl bitrate

To configure the shdsl bit rate, use the shdsl bitrate DSL profile configuration command. To disable, use the no form of this command.

shdsl bitrate rate

no shdsl bitrate

Syntax Description

rate

Specifies the maximum symmetrical data transmission rate for a G.SHDSL link.

Valid rates are 72, 136, 200, 264, 392, 520, 776, 1032, 1160, 1544, 2056, and 2312 kbps.

Defaults

no shdsl bitrate

The default setting specifies a line rate of 776 kbps.

Command Modes

DSL profile configuration

Command History

Release Modification

12.1(7)DA

This command was introduced.

Usage Guidelines

Changing the bit rate on a live port results in a retrain of the line.

Examples

The following example shows how to use the shdsl bitrate command to configure the upstream and downstream bandwidth at 2312 kbps:

dsl-profile austin  shdsl bitrate 2312

Related Commands

Command Description

shdsl set bitrate rate masktype symmetric annex {a | b}

Configures the bit rate, mask type, and annex type on a DSL profile.

shdsl margin {min dB | threshold dB | target dB}

Configures margin values, in decibels, on a DSL profile.

shdsl margin

To configure shdsl margins, use the shdsl margin DSL profile configuration command. To disable, use the no form of this command.

shdsl margin target dB

shdsl margin min dB

shdsl margin threshold dB

no shdsl margin target

no shdsl margin min

no shdsl margin threshold

Syntax Description

target

Configures the target SNR margin for the selected DSL profile. If the actual SNR margin is less than the configured target SNR margin, during the first 5 seconds of training, the line attempts to retrain.

dB

0 to 31 is the configurable range of values in decibels.

min

Configures the minimum SNR margin for the selected DSL profile. If the SNR falls below the configured value after the line has been trained for five seconds, the line will drop and attempt to retrain.

dB

0 to 31 is the configurable range of values in decibels.

threshold

Configures the minimum SNR threshold margin. If the SNR margin falls below the configured value, an SNR margin threshold alarm is issued.

dB

0 to 31 is the configurable range of values in decibels.

Defaults

The default setting, no shdsl margin configures the following threshold values:

Command Modes

DSL profile configuration.

Command History

Release Modification

12.1(7)DA

This command was introduced.

Usage Guidelines

Changing the SHDSL margin on a live port results in a retrain of the line.

Examples

The following example configures the SHDSL margin values min 2, threshold 10, and target 0:

dsl-profile austin  shdsl margin min 2  shdsl margin threshold 10  shdsl margin target 0

Related Commands

Command Description

shdsl set bitrate rate masktype symmetric annex {a | b}

Configures the bit rate, mask type, and annex type on a DSL profile.

shdsl masktype

To set the G.SHDSL mask type, use the shdsl masktype command in DSL profile configuration mode. To use the default mask type, use the no form of this command.

shdsl masktype masktype

no shdsl masktype

Syntax Description

symmetric

Configures symmetric mask type in the selected DSL profile.

Defaults

The default shdsl masktype is symmetric.

Command Modes

DSL profile configuration.

Command History

Release Modification

12.1(7)DA

This command was introduced.

Usage Guidelines

Changing the SHDSL mask type on a live port results in a retrain of the line.

Examples

The following example configures a symmetric mask type:

dsl-profile austin  shdsl masktype symmetric

Related Commands

Command Description

shdsl set bitrate rate masktype symmetric annex {a | b}

Configures the bit rate, mask type, and annex type on a DSL profile.

shdsl margin {min dB | threshold dB | target dB}

Configures margin values, in decibels, on a DSL profile.

shdsl set bitrate masktype annex

The shdsl set bitrate masktype annex aggregates the configuration of SHDSL bit rates, mask types, and annex types. To configure SHDSL bit rates, mask types, and annex types, use the shdsl set bitrate masktype annex command in DSL profile configuration mode. To disable, use the no form of this command.

shdsl set bitrate rate masktype symmetric annex {a | b}

no shdsl set bitrate masktype annex

Syntax Description

bitrate

Specifies the maximum symmetrical data transmission rate for a G.SHDSL link.

rate

Valid rates are 72, 136, 200, 264, 392, 520, 776, 1032, 1160, 1544, 2056, and 2312 kbps.

masktype

Configures the SHDSL mask type for the selected DSL profile.

symmetric

Configures a symmetric mask type for the selected DSL profile.

annex

Configures the annex type for the selected DSL profile.

a

Configures Annex A for the selected DSL profile.

b

Configures Annex B for the selected DSL profile.

Defaults

The default no shdsl set bitrate rate masktype symmetric annex {a | b} configures the following values on the selected DSL profile:

Command Modes

DSL profile configuration.

Command History

Release Modification

12.1(7)DA

This command was introduced.

Usage Guidelines

Changing the SHDSL bit rate, mask type, and annex type on a live port results in a retrain of the line.

Examples

The following example configures a 1544 kbps bit rate, symmetric mask type, and Annex A:

dsl-profile austin  shdsl set bitrate 1544 masktype symmetric annex a

Related Commands

Command Description

shdsl annex {a | b}

Configures the annex type on a DSL profile.

shdsl bitrate rate

Configures the bit rate on a DSL profile.

shdsl masktype symmetric

Configures the mask type on a DSL profile.

shdsl margin {min dB | threshold dB | target dB}

Configures margin values, in decibels, on a DSL profile.

show dsl status shdsl

To troubleshoot SHDSL ports, use the show dsl status shdsl command.

show dsl status shdsl

Syntax Description

The command has no arguments or keywords.

Command Modes

EXEC

Command History

Release Modification

12.1(7)DA

This command was modified to provide G.SHDSL specific feedback.

Usage Guidelines

Use this command to determine the administrative and operational status of each port. Nothing is displayed for slots that are empty and unprovisioned. This command also provides information on SNRs, HEC errors, line rates, receiver gain, and SHDSL cards detected.

Examples

The following example shows output from the show DSL status shdsl command:

show DSL status shdsl Subtend Node ID: 0 RATE RCVR TX RCVR HEC NUM of CARD NAME ADMIN/OPER (Kb) GAIN POWER SNR ERROR CHANGES DETECT ---- ---------- ------- ---- ------ ------ ------ ------- ------ ATM1/1 UP/ UP 2312 9 8 41 0 32 2 ATM1/2 UP/ UP 2312 9 8 41 0 32 2 ATM1/3 UP/ UP 2312 9 8 42 0 32 2 ATM1/4 UP/ UP 2312 8 8 44 0 32 2 ATM1/5 UP/ UP 2312 9 8 52 0 32 2 ATM1/6 UP/ UP 2312 8 8 43 0 32 2

Related Commands

Command Description

show dsl status

Displays generic DSL interface information.

Glossary

A

AAL5

ATM adaptation layer 5. This layer maps higher layer user data into ATM cells, making the data suitable for transport through the ATM network.

access identifier

See AID.

address mask

A bit mask used to select bits from an Internet address for subnet addressing. The mask is 32 bits long and selects the network portion of the Internet address and one or more bits of the local portion. Sometimes called subnet mask.

ADSL

asymmetric digital subscriber line. A digital subscriber line (DSL) technology in which the transmission of data from server to client is much faster than the transmission from the client to the server.

ADSL Transmission Unit—central office

See ATU-C.

ADSL Transmission Unit—remote

See ATU-R.

AID

access identifier.

AIS

alarm indication signal.

American National Standards Institute

See ANSI.

American Wire Gauge

See AWG.

ANSI

American National Standards Institute. An organization that develops standards for many things, only some having to do with computers. ANSI is a member of the International Standards Organization (ISO). See ISO.

asymmetric digital subscriber line

See ADSL.

asynchronous communications

A method of transmitting data in which each transmitted character is sent separately. The character has integral start and stop bits so that the character can be sent at an arbitrary time, and separate from any other character.

Asynchronous Transfer Mode

See ATM.

ATM

Asynchronous Transfer Mode. A cell-based data transfer technique in which channel demand determines packet allocation. ATM offers fast packet technology, real time, demand led switching for efficient use of network resources.

ATM adaptation layer 5

See AAL5.

ATU-C

ADSL Transmission Unit—central office.

ATU-R

ADSL Transmission Unit—remote.

authentication

A security feature that allows access to information to be granted on an individual basis.

autonegotiation

Procedure for adjusting line speeds and other communication parameters automatically between two computers during data transfer.

AWG

American Wire Gauge. The measurement of thickness of a wire.

D

DDTS

Cisco Distributed Defect Tracking System.

digital signal level 3

See DS3.

Distributed Defect Tracking System

See DDTS.

DS3

digital signal level 3. Framing specification used for transmitting digital signals at 44.736 Mbps on a T3 facility.

DSLAM

Digital Subscriber Line Access Multiplexer. Concentrates and multiplexes digital subscriber line signals at the telephone service provider location to the broadband wide area network. Replaces ADSLAM.

E

E1

A digital carrier that is used to transmit a formatted signal at 2.048 Mbps.

E3

A digital carrier that is used to transmit a formatted signal at 34.368 Mbps.

EEPROM

Electronically erasable programmable read-only memory. EPROM that can be erased suing electrical signals applied to specific pins.

F

frame

A packet as it is transmitted over a serial line. The term derives from character oriented protocols where special start-of-frame and end-of-frame characters were added when transmitting packets.

FTP

File Transfer Protocol. The Internet protocol (and program) used to transfer files between hosts.

G

g.832 ADM

ITU-T framing standard that defines the mapping of ATM cells into the physical medium.

gateway

A system which does translation from some native format to another. Examples include X.400 to/from RFC 822 electronic mail gateways. See router.

I

IMA

Inverse Multiplexing over ATM. Standard protocol defined by the ATM Forum in 1997.

IP

Internet Protocol. The network layer protocol for the Internet Protocol suite.

IP address

The 32-bit address assigned to hosts that want to participate in a TCP/IP Internet.

L

LCD

Loss of Cell Delineation

LODS

LOss Of Delay Synchronization

LOF

Loss Of Frame.

LOS

Loss Of Signal.

loopback

A diagnostic test that returns the transmitted signal back to the sending device after it has passed through a network or across a particular link. The returned signal can then be compared to the transmitted one. The discrepancies between the two help to trace the fault. When trying to locate a faulty piece of equipment, loopbacks will be repeated, eliminating satisfactory machines until the problem is found.

LOS

loss of signal.

M

Management Information Base

See MIB.

signal-to-noise ratio (SNR) margin

Represents the amount of increased received signal noise (in decibels) relative to the signal noise power level the unit is designed to tolerate without disconnecting from the network.

MIB

Management Information Base. A collection of objects that can be accessed via a network management protocol, such as SNMP and CMIP (Common Management Information Protocol).

N

NI-2

A second generation network interface card.

O

OOF

Out Of Frame.

R

route

The path that network traffic takes from its source to its destination. The route a datagram may follow can include many gateways and many physical networks. In the Internet, each datagram is routed separately.

router

A system responsible for making decisions about which of several paths network (or Internet) traffic will follow. To do this, it uses a routing protocol to gain information about the network and algorithms to choose the best route based on several criteria known as "routing metrics." See also bridge.

routing table

Information stored within a router that contains network path and status information. It is used to select the most appropriate route to forward information along.

S

Simple Network Management Protocol

See SNMP.

slot

A numbered location within a chassis capable of housing a module.

SNMP

Simple Network Management Protocol. The network management protocol of choice for TCP/IP-based internets.

T

T3

A digital carrier that is used to transmit a DS3 formatted digital signal at 45 Mbps.

TCP

Transmission Control Protocol. The major transport protocol in the Internet suite of protocols providing reliable, connection-oriented full-duplex streams.

Telnet

The virtual terminal protocol in the Internet suite of protocols. Allows users of one host to log into a remote host and act as normal terminal users of that host.

TFTP

Trivial File Transfer Protocol. A simple file transfer protocol (a simplified version of FTP) that is often used to boot diskless workstations and other network devices such as routers over a network (typically a LAN). Has no password security.

training

The procedure used by the ATU-C and ATU-R to establish an end-to-end ADSL connection.

training mode

Characteristic of a router that allows it to use RADSL technology to adjust its line speed according to noise conditions on the transmission line.

Transmission Control Protocol

See TCP.

Trivial File Transfer Protocol

See TFTP.

twisted pair

Two insulated copper wires twisted together with the twists or lays varied in length to reduce potential signal interference between the pairs.

U

UNI

User-Network Interface.

UNI signaling

User-Network Interface signaling for ATM communications.

upstream rate

The line rate for message or data transfer from the source machine to a destination machine on the network. Also see downstream rate.

V

VC

Virtual Circuit. A logical circuit created to ensure reliable communication between two network devices. A virtual circuit is defined by a VPI/VCI pair, and can be either permanent (PVC) or switched (SVC). In ATM, a virtual circuit is called a virtual channel. Sometimes abbreviated VC. See also PVC, SVC, VCI, and VPI.

virtual circuit

See VC.

VPI

Virtual Path Identifier. An 8-bit field in the header of an ATM cell. The VPI, together with the VCI, is used to identify the next destination of a cell as it passes through the network. See also VCI.


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Posted: Thu May 3 14:24:58 PDT 2001
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