Table of Contents

General
Circuit Emulation Service (CES)
CSM7810 Application

TDM Ports
CES modes
ATM Level

Line Configuration
Maintenance
CES Configuration
History
Statistics
CES Configuration Procedures

Factory default
E1 default
Services default
Port configuration

Selecting E1 or T1 operation
Selecting line code
Selecting framing format
Selecting CES mode
Selecting CES clock recovery scheme
Selecting UDT alarms handling

Service configuration

Setting a UDT service
Setting a SDT service
Deleting a service
Selecting CSM7810 as timing source

CSM

This chapter deals with CSM LIM Configuration:

• General

• Circuit Emulation Service (CES)

• CSM7810 Application

• Line Configuration

• Maintenance

• CES Configuration

• History

• Statistics

• CES Configuration Procedures

General

The Compact Subscriber Module (CSM) supports Circuit Emulation Services (CES) on an E1/DS1 interface. The CSM (DS1 and E1 interfaces) provides adaptation from time-division multiplexed (TDM) equipment (i.e. PBX's, WAN multiplexers, channel banks, video codecs, etc.) and traffic to ATM. In both E1 and DS1 modes structured and unstructured services can be provided with a maximum of 96 and 120 connections supported on each module.

The CSM Network Module has 4 ports which support fractional DS1 services (n x 56 kbps/n 64 kbps) where 1 to 24 contiguous or non-contiguous DS0 channels are mapped to a single ATM VCC not to exceed 127 total connections.

Structured services provide digital access and cross-connect system connectivity where n x 64 kbps and n x 56 kbps digital signal level zero (DS0) channels are adapted to ATM cells and mapped to unique ATM virtual connections (VCCs). Unstructured services provide support and maintenance of a single full bandwidth 1.544 Mbps (DS1) or 2.048 Mbps (E1) clear channel across a single ATM virtual connection. Configurations of both the DS1 and the E1 version of the CSM module are detailed in this chapter.

The CSM, shown in Figure 14-1 utilizes the AAL1 SAR and enables transferring PBX calls over an ATM network. Its front panel is shown in Figure 1-5 (chapter 1).

Circuit Emulation Service (CES)

The Cisco 8110 supports up to two CSM 7810 modules, each providing 4 CES User ports. Port and Service modes and parameters can be configured.

CES is an option supported by Cisco 8110 software release 4.0 and up. To add CES support to the Cisco 8110 at least one CM7810 module should be installed in interface slots 1 or 3 (User side). The Cisco 8110 supports two of these modules.

CSM7810 Application

TDM Ports

The four TDM ports can be selected to be either E1 or T1, for each CSM7810. The framing format and line code can be selected.

Supported line codes are:

• For T1: B8ZS and AMI

• For E1: HDB3

Supported framing formats are:

• For T1: SF and ESF

• For E1: FAS, MFAS, FAS+CRC, MFAS+CRC

Channels may be programmed individually to carry CAS signaling or not. Different option of trunk conditioning in case of failures are provided.

Maintenance and statistics are accumulated for each port in a similar way to other LIM cards, but no cells related parameters are accumulated (Ingress, Egress and Errored cells), since the interface is TDM and not ATM.

The CSM7810 can provide the Cisco 8110 clock source from the recovered clock of any of its input signals.

CES modes

UDT and SDT modes are supported on a per port basis.

In UDT mode only one service can be configured per port. The alarms handling can be selected to handle only LOS alarms, to handle LOS and monitor all other frame alarms, or to monitor and handle all frame alarms.

In SDT mode up to 24 (T1) or 31 (E1) services can be configured per port. Each service may include between one and all channels of a port. Each service can be selected to carry or not CAS signaling.

In both modes the clock recovery scheme can be selected. The supported schemes are: Internal, Adaptive and Loop timed. Cells fill level can be set to reduce delay.

ATM Level

Each service should be associated with a VC. The VC features are the same as for a regular VC in the Network side. In the User side no OAM generation or handling is performed, since the ATM Interface in the User side is internal to the Cisco 8110.

By default CES related alarms will not force VC-AIS alarms. VC alarms are reported to the CES level for consequent actions.

Line Configuration

The CSM card is configured on both the CBR and ATM side. Configuration of the CBR side of the CSM may be performed using the following menus. Access to CSM configuration is via the DSX1 configuration menu.

Step 2   Type any portion of the word configuration and press RETURN. Then type? and press RETURN. The Configuration Menu is displayed.

Step 3   Type dsx1 at the prompt and press RETURN. Then type ? and press RETURN to display the DSX1 Configuration menu:

LINE_TYPE This command allows the user to select the protocol (E1, T1) This selection remains until reconfigured. At the prompt, type the command and press RETURN. The following prompt is displayed:

BUILD_OUT This command sets the physical interface line buildout characteristics for CSM-T1 and LIM-T1 modes. At the prompt, type the command and press RETURN. The following prompt is displayed: T-1 Mode Only

ATTENUATION This command is used to set the attenuation in LIM-T1 and CMS-T1 (when build-out is long). At the prompt, type the command and press RETURN. The following prompt is displayed:

LINE_BAL This command is used to enable or disable line balance for LIM-E1.

payload This command enables the payload scrambling at the ATM level for all types of LIM (i.e. LIM-E1, LIM-T1).

coset An ATM parameter which indicates when to calculate the header error correction bit if it is to be ORed with another value or not (known as the COSET Polynomial). It is applicable for LIM-E1 and LIM-T1.

CSM This command configures the Circuit Emulation Services. At the prompt, type the command and press RETURN. The following screen is displayed:

T1_FRAMING This command is used to enable or disable CAS (Channel Associated Signalling). At the prompt, type the command and press RETURN. The following prompt is displayed:

E1_FRAMING This command is used to enable or disable Channel Associated Signalling. At the prompt, type the command and press RETURN. The following prompt is displayed:

LINE_CODE This command defines the line encoding in T1 mode only and allows selection between two standards: AMI or B8ZS. At the prompt, type the command and press RETURN. The following prompt is displayed:

TRUNK_CONDITION This command is used to enable the trunk conditioning option for SDT mode. This configures the a,b,c,d (a,b in T1-SF mode) bit. At the prompt, type the command and press RETURN. The following prompt is displayed:

DT_MODE This command is used to select the type of data transfer ( structured or unstructured). At the prompt, type the command and press RETURN. The following prompt is displayed:

UDT_ALARM This command is used to select the Unstructured Data Transfer, UDT, option and determine when to declare an alarm and which action is to be taken. At the prompt, type the command and press RETURN. The following prompt is displayed:

CLOCK_RECOVERY This command is used to select the clock recovery scheme. At the prompt, type the command and press RETURN. The following prompt is displayed:

alarm This command enters the DSX1 alarm configuration submenu. At the prompt, type the command and press RETURN. The following screen as shown in Figure 14-6 is displayed:

SHOW This command displays the DSX1 alarm configuration. At the prompt, type the command and press RETURN. The following information as shown in Figure 14-7 is displayed:

high_ber This command sets BER high alarm threshold to 10-x. At the prompt, type the command and press RETURN. The following prompt is displayed:

low_ber This command sets BER low alarm threshold to 10-x. At the prompt, type the command and press RETURN. The following prompt is displayed:

PM This command enteres the DS1 Performance Monitoring submenu. At the prompt, type the command and press RETURN. The screen shown in Figure 14-8 is displayed:

SHOW This command displays the DS1 LIM performance monitoring thresholds. At the prompt, type the command and press RETURN. The type of information shown in Figure 14-9 is displayed:

DEGRADED This command defines how many Line Code Violations should have occurred in the previous 24 hours to declare a degraded performance. At the prompt, type the command and press RETURN. The following prompt is displayed:

UNACCEPTABLE This command defines how many Line Code Violations should have occurred in the previous 15 minute to declare an unacceptable performance. At the prompt, type the command and press RETURN. The following prompt is displayed:

ses_threshold This command defines the number of errored seconds (ES) in the previous 15 minutes to declare a severely errored second. At the prompt, type the command and press RETURN. The following prompt is displayed:

STATUS This command enables or disables the performance monitoring (PM). At the prompt, type the command and press RETURN. The following prompt is displayed:

CLEAR This command clears the relavent performance monitoring (PM) current or history parameters. At the prompt, type the command and press RETURN. The following prompt is displayed:

Maintenance

Step 2   Type any portion of the word maintenance and press RETURN. Then type ? and press RETURN The Maintennce Menu is displayed.

LOOPBACK This command sets the DSX1 interface loopback mode. At the prompt, type the command and press RETURN. The following prompt is displayed:

DET_LOOP_CODES This command enables dection of loop codes sent by the remote system.

SEND_CODE This command sends the pattern of loop code using BOP protocols in order to set loopback in the remote side. At the prompt, type the command and press RETURN. The following prompt is displayed:

CES Configuration

The CSM card is configured on both the CBR and ATM side. Configuration of the ATM side of the CSM may be performed using the following menus.

Step 2   Type ces at the prompt and press RETURN. Then type ? and press RETURN to display the CES Configuration menu.

SHOW This command displays CES configuration parameters as shown in the sample screen in Figure 14-12.

PCR and CDV computations are implemented for CES connections.

The PCR computation complies with af-vtoa-0078.000 par. 5.1.

The CDV depends on the number of active connections. As the CBR traffic is already shaped as required, no policing is needed to be performed by these connections. These computed parameters may be used by the user to configure the PVCs in the Network switches.

Class 0 is assigned as a default class of highest priority for CBR connections. Other connections will use class 31 as default. This will assure that when there is a contention on the network port (traffic coming from ethernet and native ATM LIM) the CBR traffic will always be serviced.

SERVICE This command is used to select the status of each service. At the prompt, type the command and press RETURN. The following prompt is displayed:

Usage: service <limid 1..3>

lim 13

selects LIM

---

Note   The If index presented is the one that should be used in commands that use the If index as a parameter (e.g..Delete, CAS etc.)

---

Figure 14-14: Service status display

Cisco 8110::Cisco 8110_b~ co ce sh ser 1 CES Services for LIM1 --------------------- IfIndex Port Channels ConnType Vpi Vci CbrType Admin Oper
385 1 00000002 pvc 0 100 SDT Up Up
512 1 00000070 pvc 0 101 SDT Up Up

---

Note   To see CES services of other LIMs, reference Figures 14-17, 14-18 and 14-19.

---

CONFIG This command is used to display the configuration. At the prompt, type the command and press RETURN. The following prompt is displayed:

Figure 14-16 shows details of service configuration CBR type UDT and its computed values for service 14.

Figure 14-18 shows details of service configuration CBR type UDT and its computed values for service 257.

NEW This command is used for assigning some of the time slots into one of the connections by selecting lim, port, channel. The connection is added to the VC table. The command will cause an interface to be created automatically. At the prompt, type the command and press RETURN. The following prompt is displayed:

DELETE This command is used to erase the connection. At the prompt, type the command and press RETURN. The following prompt is displayed:

CAS This command is used to determine whether channel associated signaling should be transferred across the connection. At the prompt, type the command and press RETURN. The following prompt is displayed:

PARTIAL_FILL This command is used to determine how many of the available bytes in each cell are used before they are deemed `full' and ready for transmission across the network in order to regulate the transmission quality. At the prompt, type the command and press RETURN. The following prompt is displayed:

BUF_MAX_SIZE This command is used to determine the amount of buffer space allocated for the nicoming cells. At the prompt, type the command and press RETURN. The following prompt is displayed:

CDV_RX_T This command is used to set cell delay variation of incoming cells over a specific time span. At the prompt, type the command and press RETURN. The following prompt is displayed:

LOSS_INTEG_TIME This command is used to determine loss integration time . At the prompt, type the command and press RETURN. The following prompt is displayed:

ENABLE This command is used to enable transfer of data. Data cannot be transferred until configured and enabled with this command. At the prompt, type the command and press RETURN. The following prompt is displayed:

DISABLE This command is used to disable a connection. At the prompt, type the command and press RETURN. The following prompt is displayed:

History

To view the History data display proceed as follows:

Step 2   Type any portion of the word statistics and press RETURN. Then type ? and press RETURN. The History Menu is displayed.

Step 3   Type lim and press RETURN. Type ? and press RETURN to display the following prompt

Far End Line : 0 : - : - : - : -

Statistics

To view statistics for LIM T1/E1, proceed as follows:

Step 2   Type any portion of the word statistics and press RETURN. Then type ? and press RETURN. The Statistics Menu is displayed.

Step 3   Type lim and press RETURN. Type ? and press RETURN to display the following screen

Line : 0 : - : 0 : - : -

Note   If no LIM number is specified, all LIM statistics will be displayed. Selected LIM statistics, can be shown if the LIM number is added to the LIM command (see Figure 14-20)

CES Configuration Procedures

Following is a description of the Cisco 8110 CES optional configuration, including commands for the most used operations.

Default configuration depends on the selected line type and CES mode.

Factory default

The CSM7810 Factory default configuration is as follows:

• Line Type T1

• Line code B8ZS

• Framing format ESF

• CES mode UDT

• Clock recovery scheme adaptive

• UDT alarms monitor LOS only

• Trunk Conditioning mode set all signaling bits to 0, then to 1

E1 default

When the CSM7810 is changed to E1 the default configuration is as follows:

• Line Type E1

• Line code HDB3

• Framing format E1 with CRC

• CES mode UDT

• Clock recovery scheme adaptive for UDT, looped timing for SDT

• UDT alarms monitor LOS only

• Trunk Conditioning mode none

Services default

The services default configuration is as follows:

• No CAS

• Partial fill 0. Send complete cells, no dummy fill.

Port configuration

The first step in using the CES option should be to set up the TDM ports operating mode.

Selecting E1 or T1 operation

The CES may be set to E1 or T1 operation. To change the line type of a CSM installed in slot 1, to E1, perform the following operation:

• Configure CES line type (from route menu):

configuration: dsx1$ line_type 1 e1

To perform this operation no services should be configured. The E1 configuration will be according to the default configuration.

Selecting line code

In T1 the line code can be selected to be B8ZS or AMI, in E1 the code is always HDB3. To change the line code of port 1, of a CSM installed in slot 3, to AMI, perform the following operation:

• Configure T1 port line code (from route menu):

configuration dsx1 csm line_code 3 1 ami

Selecting framing format

In T1 the farming can be selected to be ESF or SF, in E1 it can be selected to be FAS, MFAS with and without CRC. To change the framing format of port 4, of a CSM installed in slot 1 and operating in E1 mode, to CRC + MFAS, perform the following operation:

• Configure E1 port framing format (from route menu):

configuration dsx1 csm e1_framing 1 4 crc_mf

E1 modes supporting CAS can not be configured if the CES mode is UDT.

Selecting CES mode

CES mode can be set to UDT or SDT. To configure SDT mode in port 1 of a CSM installed in slot 3 perform the following operation:

• Configure SDT mode to SDT (from route menu):

configuration dsx1 csm dt_mode 3 1 sdt

To perform this operation no services should be configured. The SDT configuration will be according to the default configuration.

Selecting CES clock recovery scheme

CES clock recovery scheme can be set to Adaptive, Loop timed or Internal. To configure Internal mode in port 4 of a CSM installed in slot 1 perform the following operation:

• Configure SDT mode to SDT (from route menu):

configuration dsx1 csm clock_recovery 1 4 internal

Selecting UDT alarms handling

UDT alarms monitoring can be selected to handle only LOS, to handle LOS and monitor all alarms or to perform consequent actions for all the alarms. To configure LOS only handling in port 2 of a CSM installed in slot 3 perform the following operation:

• Configure UDT alarms monitoring to LOS only (from route menu):

configuration dsx1 csm udt_alarms 3 2 los

Service configuration

Once the port and CES mode have been selected, services can be configured depending on the selected mode and framing format.

To configure a service, the service should be defined and then associated to a VC. Once the VC and the Service have been enabled, information starts flowing.

Each Service will be assigned an ID that will be used to refer to that service.

Setting a UDT service

In the following example we will describe how to set a UDT service associated to port 2 of a CSM7810 installed in slot 1, that uses VC with VPI = 0, VCI = 100.

• Set the service (from route menu):

configuration ces new 1 2 all 0 100

• Verify that service ID number:

Note   "all" is the only option for the number of channels in UDT mode

configuration ces show service 1

• Enable the Service (assume the ID is 5) (from route menu):

configuration ces enable 5

• Set the associated VC (from route menu):

configuration vc new 0 100 ces1

• Enable the associated VC (from route menu):

configuration: vc$ enable 0 100

Setting a SDT service

In the following example we will describe how to set a SDT service associated to port 4 of a CSM7810 installed in slot 1, that uses VC with VPI = 0, VCI = 101. The service will carry channels 5 to 8 with CAS.

• Set the service (from route menu):

configuration ces new 1 4 5-8 0 101

• Verify that service ID number (from route menu):

configuration ces show service 1

• Enable the Service (assume the ID is 385 - from route menu):

configuration ces enable 385

• Enable the CAS (from route menu):

configuration ces cas 385 enable

• Set the associated VC (from route menu):

configuration vc new 0 101 ces1

• Enable the associated VC (from route menu):

configuration vc enable 0 101

Deleting a service

In the following example we will delete the service that was configured in the previous paragraph.

• Delete the VC (from route menu):

configuration vc delete 0 100

• Delete the Service (from route menu):

configuration ces delete 385

Selecting CSM7810 as timing source

Any port of the CSM7810 can be used as the Cisco 8110 timing source. To configure port 2 of the CSM7810 installed in slot 3 as the Cisco 8110 primary timing source, perform the following operation:

• Select the CSM7810 as the primary timing source (from route menu):

configuration tim primary lim3

• Select the port as timing source (from route menu):

configuration dsx1 csm clock_source 3 2

Step 4  

Posted: Tue Mar 13 09:49:44 PST 2001
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