Cisco ASR 903 Router Chassis Software Configuration Guide, IOS XE Release 3.7
Configuring T1/E1 Interfaces
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Configuring T1/E1 Interfaces

Table Of Contents

Configuring T1/E1 Interfaces

Configuration Tasks

Limitations

Required Configuration Tasks

Setting the Card Type

Configuring the Controller

Verifying Controller Configuration

Optional Configurations

Configuring Framing

Saving the Configuration

Troubleshooting E1 and T1 Controllers

Setting Loopbacks

Run Bit Error Rate Test

Monitoring and Maintaining the T1/E1 Interface Module

Configuring Circuit Emulation

Configuring a CEM Group

Using CEM Classes

Configuring CEM Parameters

Configuring Payload Size

Setting the Dejitter Buffer Size

Setting an Idle Pattern

Enabling Dummy Mode

Setting a Dummy Pattern

Shutting Down a CEM Channel

Configuring ATM

Configuring a Clear-Channel ATM Interface

Configuring ATM IMA

Verifying the Interface Configuration

Verifying Per-Port Interface Status

Configuration Examples

Example: Framing and Encapsulation Configuration

Example: CRC Configuration

Example: Facility Data Link Configuration

Example: Invert Data on the T1/E1 Interface

Example: CEM Configuration

Example: ATM IMA Configuration


Configuring T1/E1 Interfaces


This chapter provides information about configuring the T1/E1 interface module on the Cisco ASR 903 Series Router. It includes the following sections:

Configuration Tasks

Configuring Circuit Emulation

Configuring ATM

Verifying the Interface Configuration

Configuration Examples

For information about managing your system images and configuration files, refer to the Cisco IOS Configuration Fundamentals Configuration Guide and Cisco IOS Configuration Fundamentals Command Reference publications.

For more information about the commands used in this chapter, refer to the Cisco IOS Command Reference publication for your Cisco IOS software release.

For more information, see the "Related Documentation" section.

Configuration Tasks

This section describes how to configure the T1/E1 interface module for the Cisco ASR 903 Series Router and includes information about verifying the configuration.

It includes the following topics:

Required Configuration Tasks

Optional Configurations

Saving the Configuration

Limitations

This section describes the software limitations that apply when configuring the T1/E1 interface module on the Cisco ASR 903 Series Router.

The following features are not currently supported on the T1/E1 interface module:

Serial interfaces—The Cisco ASR 903 Series Router does not currently support serial interfaces or features applied to serial interfaces. We recommend that you use a configuration with CEM or ATM IMA as a workaround.

ATM IMA groups—Configuration of more than 16 IMA groups on each T1/E1 interface module.

Supported BERT patterns—Currently only the 2^11, 2^15, 2^20-O153, and 2^20-QRSS patterns are supported.

Required Configuration Tasks

This section lists the required configuration steps to configure the T1/E1 interface module. Some of the required configuration commands implement default values that might be appropriate for your network. If the default value is correct for your network, then you do not need to configure the command.

Setting the Card Type

Configuring the Controller

Verifying Controller Configuration

Optional Configurations

Setting the Card Type

The interface module is not functional until the card type is set. Information about the interface module is not indicated in the output of any show commands until the card type has been set. There is no default card type.


Note Mixing of T1 and E1 interface types is not supported. All ports on the interface module must be of the same type.


To set the card type for the T1/E1 interface module, complete these steps:

 
Command
Purpose

Step 1 

Router# configure terminal

Enters global configuration mode.

Step 2 

Router(config)# card type {e1 | t1} slot subslot

Sets the serial mode for the interface module:

t1—Specifies T1 connectivity of 1.536 Mbps. B8ZS is the default linecode for T1.

e1—Specifies a wide-area digital transmission scheme used predominantly in Europe that carries data at a rate of 1.984 Mbps in framed mode and 2.048 Mbps in unframed E1 mode.

slot subslot—Specifies the location of the interface module.

Step 3 

Router(config)# exit

Exits configuration mode and returns to the EXEC command interpreter prompt.

Configuring the Controller

To create the interfaces for the T1/E1 interface module, complete these steps:

 
Command
Purpose

Step 1 

Router# configure terminal

Enters global configuration mode.

Step 2 

Router(config)# controller {t1 | e1} slot/subslot/port

Selects the controller to configure and enters controller configuration mode.

t1—Specifies the T1 controller.

e1—Specifies the E1 controller.

slot/subslot/port—Specifies the location of the interface.

Note The slot number is always 0.

Step 3 

Router(config-controller)# clock source {internal | line}

Sets the clock source.

Note The clock source is set to internal if the opposite end of the connection is set to line and the clock source is set to line if the opposite end of the connection is set to internal.

internal—Specifies that the internal clock source is used.

line—Specifies that the network clock source is used. This is the default for T1 and E1.

Step 4 

Router(config-controller)# linecode {ami | b8zs | hdb3}

Selects the linecode type.

ami—Specifies Alternate Mark Inversion (AMI) as the linecode type. Valid for T1 and E1 controllers.

b8zs—Specifies binary 8-zero substitution (B8ZS) as the linecode type. Valid for T1 controller only. This is the default for T1 lines.

hdb3—Specifies high-density binary 3 (HDB3) as the linecode type. Valid for E1 controller only. This is the default for E1 lines.

Step 5 

For T1 Controllers:

Router(config-controller)# framing {sf | esf}

For E1 Controllers:

Router(config-controller)# framing {crc4 | no-crc4}

Selects the framing type.

sf—Specifies Super Frame as the T1 frame type.

esf—Specifies Extended Super Frame as the T1 frame type. This is the default for E1.

crc4—Specifies CRC4 as the E1 frame type. This is the default for E1.

no-crc4—Specifies no CRC4 as the E1 frame type.

Step 6 

cablelength {long | short}

Example:
Router(config-controller)# 
cablelength long

To fine-tune the pulse of a signal at the receiver for an E1 cable, use the cablelength command in controller configuration mode.

Step 7 

exit

Example:

Router(config)# exit

Exits configuration mode and returns to the EXEC command interpreter prompt.

Verifying Controller Configuration

To verify the controller configuration, use the show controllers command :

 
   
Router# show controllers t1 0/3/0 brief
T1 0/3/0 is up.
  Applique type is A900-IMA16D
  Cablelength is long gain36 0db
  No alarms detected.
  alarm-trigger is not set
  Soaking time: 3, Clearance time: 10
  AIS State:Clear  LOS State:Clear  LOF State:Clear
  Framing is ESF, Line Code is B8ZS, Clock Source is Internal.
  Data in current interval (230 seconds elapsed):
     0 Line Code Violations, 0 Path Code Violations
     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
     0 Near-end path failures, 0 Far-end path failures, 0 SEF/AIS Secs
  Total Data (last 24 hours)
     136 Line Code Violations, 63 Path Code Violations,
     0 Slip Secs, 6 Fr Loss Secs, 4 Line Err Secs, 0 Degraded Mins,
     7 Errored Secs, 1 Bursty Err Secs, 6 Severely Err Secs, 458 Unavail Secs
     2 Near-end path failures, 0 Far-end path failures, 0 SEF/AIS Secs

Optional Configurations

There are several standard, but optional, configurations that might be necessary to complete the configuration of your T1/E1 interface module.

Configuring Framing

Saving the Configuration

Configuring Framing

Framing is used to synchronize data transmission on the line. Framing allows the hardware to determine when each packet starts and ends. To configure framing, use the following commands.

 
Command
Purpose

Step 1 

Router# configure terminal

Enters global configuration mode.

Step 2 

Router(config)# controller {t1 | e1} slot/subslot/port

Selects the controller to configure.

t1—Specifies the T1 controller.

e1—Specifies the E1 controller.

slot/subslot/port—Specifies the location of the controller.

Note The slot number is always 0.

Step 3 

For T1 controllers

Router(config-controller)# framing {sf | esf}

For E1 controllers

Router(config-controller)# framing {crc4 | no-crc4}

Sets the framing on the interface.

sf—Specifies Super Frame as the T1 frame type.

esf—Specifies Extended Super Frame as the T1 frame type. This is the default for T1.

crc4—Specifies CRC4 frame as the E1 frame type. This is the default for E1.

no-crc4—Specifies no CRC4 as the E1 frame type.

Step 4 

exit

Example:

Router(config)# exit

Exits configuration mode and returns to the EXEC command interpreter prompt.

Verifying Framing Configuration

Use the show controllers command to verify the framing configuration:

Router# show controllers t1 0/3/0 brief
T1 0/3/0 is up.
  Applique type is A900-IMA16D
  Cablelength is long gain36 0db
  No alarms detected.
  alarm-trigger is not set
  Soaking time: 3, Clearance time: 10
  AIS State:Clear  LOS State:Clear  LOF State:Clear
  Framing is ESF, Line Code is B8ZS, Clock Source is Line.
  Data in current interval (740 seconds elapsed):
     0 Line Code Violations, 0 Path Code Violations
     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
     0 Near-end path failures, 0 Far-end path failures, 0 SEF/AIS Secs
  Total Data (last 24 hours)
     0 Line Code Violations, 0 Path Code Violations,
     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
     0 Near-end path failures, 0 Far-end path failures, 0 SEF/AIS Secs
 
   

Saving the Configuration

To save your running configuration to nonvolatile random-access memory (NVRAM), use the following command in privileged EXEC configuration mode:

Command
Purpose

Router# copy running-config startup-config

Writes the new configuration to NVRAM.


For information about managing your system images and configuration files, refer to the Cisco IOS Configuration Fundamentals Configuration Guide and Cisco IOS Configuration Fundamentals Command Reference publications.

Troubleshooting E1 and T1 Controllers

You can use the following methods to troubleshoot the E1 and T1 controllers using Cisco IOS software:

Setting Loopbacks

Run Bit Error Rate Test

Setting Loopbacks

The following sections describe how to set loopbacks:

Setting a Loopback on the E1 Controller

Setting a Loopback on the T1 Controller

Setting a Loopback on the E1 Controller

To set a loopback on the E1 controller, perform the first task followed by any of the following tasks beginning in global configuration mode:

Command
Purpose

Router# configure terminal

Enters global configuration mode.

Select the E1 controller and enter controller configuration mode.

controller e1 slot/subslot/port

Note The slot number is always 0.

Set a diagnostic loopback on the E1 line.

loopback diag

Set a network payload loopback on the E1 line.

loopback network {line | payload}

Exit configuration mode when you have finished configuring the controller.

end


Setting a Loopback on the T1 Controller

You can use the following loopback commands on the T1 controller in global configuration mode:

Task
Command

Selects the T1 controller and enter controller configuration mode.

controller t1 slot/subslot/port

Note The slot number is always 0.

Sets a diagnostic loopback on the T1 line.

loopback diag

Sets a local loopback on the T1 line. You can select to loopback the line or the payload.

loopback local {line | payload}

Sets a remote loopback on the T1 line. This loopback setting will loopback the far end at line or payload, using IBOC (in band bit-orientated code) or the Extended Super Frame (ESF) loopback codes to communicate the request to the far end.

loopback remote iboc

Exits configuration mode when you have finished configuring the controller.

end



Note To remove a loopback, use the no loopback command.


Table 8-1 Loopback Descriptions

Loopback
Description

loopback diag

Loops the outgoing transmit signal back to the receive signal. This is done using the diagnostic loopback feature in the interface module's PMC framer. The interface module transmits AIS in this mode. Set the clock source command to internal for this loopback mode.

loopback local

Loops the incoming receive signal back out to the transmitter. You can specify whether to use the line or payload.

local line

The incoming signal is looped back in the interface module using the framer's line loopback mode. The framer does not reclock or reframe the incoming data. All incoming data is received by the interface module driver.

local payload

Loops the incoming signal back in the interface module using the payload loopback mode of the framer. The framer reclocks and reframes the incoming data before sending it back out to the network. When in payload loopback mode, an all 1s data pattern is received by the local HDLC receiver and the clock source is automatically set to line (overriding the clock source command). When the payload loopback is ended, the clock source returns to the last setting selected by the clock source command.

loopback remote iboc

Attempts to set the far-end T1 interface into line loopback. This command sends an in-band bit-oriented code to the far-end to cause it to go into line loopback. This command is available when using ESF or SF framing mode.

network line

Loops the incoming signal back in the interface module using the line loopback mode of the framer. The framer does not reclock or reframe the incoming data. All incoming data is received by the interface module driver.

network payload

Loops the incoming signal back using the payload loopback mode of the framer. The framer reclocks and reframes the incoming data before sending it back out to the network. When in payload loopback mode, an all 1s data pattern is received by the local HDLC receiver, and the clock source is automatically set to line (overriding the clock source command). When the payload loopback is ended, the clock source returns to the last setting selected by the clock source command.


Run Bit Error Rate Test

Bit error rate testing (BERT) is supported on each of the E1 or T1 links. The BERT testing is done only over a framed E1 or T1 signal and can be run only on one port at a time.

The interface modules contain onboard BERT circuitry. With this, the interface module software can send and detect a programmable pattern that is compliant with CCITT/ITU O.151, O.152, and O.153 pseudo-random and repetitive test patterns. BERTs allows you to test cables and signal problems in the field.

When running a BER test, your system expects to receive the same pattern that it is transmitting. To help ensure this, two common options are available:

Use a loopback somewhere in the link or network

Configure remote testing equipment to transmit the same BERT test pattern at the same time

To run a BERT on an E1 or T1 controller, perform the following optional tasks beginning in global configuration mode:

Task
Command

Selects the E1 or T1 controller and enters controller configuration mode.

Router(config)# controller {e1 | t1} slot/subslot/port

Note The slot number is always 0.

Specifies the BERT pattern for the E1 or T1 line and the duration of the test in minutes. The valid range is 1 to 1440 minutes.

Note Only the 2^11, 2^15, 2^20-O153, and 2^20-QRSS patterns are supported.

Router(config-controller)# bert pattern {0s | 1s | 2^11 | 2^15 | 2^20-O153 | 2^20-QRSS | 2^23 | alt-0-1} interval minutes

Exit configuration mode when you have finished configuring the controller.

Router(config-controller)# end

Displays the BERT results.

show controllers {e1 | t1} slot/subslot/port


The following keywords list different BERT keywords and their descriptions.


Caution Currently only the 2^11, 2^15, 2^20-O153, and 2^20-QRSS patterns are supported.

Table 8-2 BERT Pattern Descriptions

Keyword
Description

0s

Repeating pattern of zeros (...000...).

1s

Repeating pattern of ones (...111...).

2^11

Pseudo-random test pattern that is 2,048 bits in length.

2^15

Pseudo-random O.151 test pattern that is 32,768 bits in length.

2^20-O153

Pseudo-random O.153 test pattern that is 1,048,575 bits in length.

2^20-QRSS

Pseudo-random QRSS O.151 test pattern that is 1,048,575 bits in length.

2^23

Pseudo-random 0.151 test pattern that is 8,388,607 bits in length.

alt-0-1

Repeating alternating pattern of zeros and ones (...01010...).


Both the total number of error bits received and the total number of bits received are available for analysis. You can select the testing period from 1 minute to 24 hours, and you can also retrieve the error statistics anytime during the BER test.


Note To terminate a BERT test during the specified test period, use the no bert command.


You can view the results of a BERT test at the following times:

After you terminate the test using the no bert command

After the test runs completely

Anytime during the test (in real time)

Monitoring and Maintaining the T1/E1 Interface Module

After configuring the new interface, you can monitor the status and maintain the interface module by using show commands. To display the status of any interface, complete any of the following tasks in EXEC mode:

Task
Command

Displays the status of the E1 or T1 controller.

show controllers {e1 | t1} [slot/port-adapter/port/e1-line] [brief]

Displays statistics about the serial information for a specific E1 or T1 channel group. Valid values are 0 to 30 for E1 and 0 to 23 for T1.

show interface serial slot/subslot/port

Clears the interface counters.

clear counters serial slot/subslot/port


Configuring Circuit Emulation

This section provides information about how to configure Circuit Emulation (CEM). CEM provides a bridge between a time-division multiplexing (TDM) network and a packet network, such as Multiprotocol Label Switching (MPLS). The router encapsulates the TDM data in the MPLS packets and sends the data over a CEM pseudowire to the remote provider edge (PE) router. Thus, function as a physical communication link across the packet network.

The following sections describe how to configure CEM:

Configuring a CEM Group

Using CEM Classes

Configuring CEM Parameters


Note CEM is used as an element in configuring pseudowires including Structure-Agnostic TDM over Packet (SAToP) and Circuit Emulation Service over Packet-Switched Network (CESoPSN). For more information about configuring pseudowires, see Chapter 12 "Configuring Pseudowire."


Configuring a CEM Group

This section describes how to configure a CEM group on the Cisco ASR 903 Series Router.

SUMMARY STEPS

1. enable

2. configure terminal

3. controller {t1 | e1} slot/subslot/port

4. cem-group group-number {unframed | timeslots timeslot}

5. end

DETAILED STEPS

 
Command
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

controller {t1 | e1} slot/subslot/port

Example:

Router(config)# controller t1 0/1/0

Enters T1 or E1 controller configuration mode.

Use the slot, subslot, and port arguments to specify the slot number and port number to be configured.

Note The slot number is always 0.

Step 4 

cem-group group-number {unframed | timeslots timeslot}

Example:

Router(config-controller)# cem-group 6 timeslots 1-4,9,10 speed 64

Creates a circuit emulation channel from one or more time slots of a T1 or E1 line.

The group-number keyword identifies the channel number to be used for this channel. For T1 ports, the range is 0 to 23. For E1 ports, the range is from 0 to 30.

Use the unframed keyword to specify that a single CEM channel is being created including all time slots and the framing structure of the line.

Use the timeslots keyword and the timeslot argument to specify the time slots to be included in the CEM channel. The list of time slots may include commas and hyphens with no spaces between the numbers.

Note The speed keyword is not currently supported.

Step 5 

end

Example:

Router(config-controller)# end

Exits controller configuration mode and returns to privileged EXEC mode.

Using CEM Classes

A CEM class allows you to create a single configuration template for multiple CEM pseudowires.


Note The CEM parameters at the local and remote ends of a CEM circuit must match; otherwise, the pseudowire between the local and remote PE routers will not come up.


Follow these steps to configure a CEM class:

SUMMARY STEPS

1. enable

2. configure terminal

3. class cem classname

4. payload-size size

5. dejitter-buffer size

6. idle-pattern {pattern | length pattern1 [pattern2]}

7. exit

8. interface cem slot/subslot/port

9. no ip address

10. cem slot/subslot/port

11. cem group-number

12. xconnect peer-ip-address vc-id {encapsulation {l2tpv3 [manual] | mpls [manual]} | pw-class pw-class-name} [pw-class pw-class-name] [sequencing {transmit | receive | both}]

13. exit

14. exit

DETAILED STEPS

 
Command
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

class cem class-name

Example:

Router(config)# class cem mycemclass

Creates a new CEM class

Step 4 

payload-size size

dejitter-buffer size

idle-pattern {pattern | length pattern1 [pattern2]}

Example:

Router(config-cem-class)# payload-size 512

dejitter-buffer 10

idle-pattern 0x55

Enter the configuration commands common to the CEM class. This example specifies a sample rate, payload size, dejitter buffer, and idle pattern.

Step 5 

exit

Example:

Router(config-cem-class)# exit

Returns to global configuration mode.

Step 6 

interface cem slot/subslot/port

no ip address

cem id

xconnect peer-router-id vcid encapsulation mpls | pw-class pw-class-name

Example:

Router(config)# interface cem 0/0/0

Router(config-if)# no ip address

Router(config-if)# cem 0

Router(config-if-cem)# xconnect 10.10.10.10 200 encapsulation mpls

Configures the CEM interface for use with the new CEM class.

Note The use of the xconnect command can vary depending on the type of pseudowire you are configuring.

Step 7 

exit

Example:

Router(config-if-cem)# exit

Router(config-if)#

Exits the CEM interface.

Step 8 

exit

Example:
Router(config)# exit

Router#

Exits configuration mode.

Configuring CEM Parameters

The following sections describe the parameters you can configure for CEM circuits.

Configuring Payload Size

Setting the Dejitter Buffer Size

Setting an Idle Pattern

Enabling Dummy Mode

Setting a Dummy Pattern

Shutting Down a CEM Channel


Note The CEM parameters at the local and remote ends of a CEM circuit must match; otherwise, the pseudowire between the local and remote PE routers will not come up.


Configuring Payload Size

To specify the number of bytes encapsulated into a single IP packet, use the payload-size command. The size argument specifies the number of bytes in the payload of each packet. The range is from 32 to 1312 bytes.

Default payload sizes for an unstructured CEM channel are as follows:

E1 = 256 bytes

T1 = 192 bytes

DS0 = 32 bytes

Default payload sizes for a structured CEM channel depend on the number of time slots that constitute the channel. Payload size (L in bytes), number of time slots (N), and packetization delay (D in milliseconds) have the following relationship: L = 8 x N x D. The default payload size is selected in such a way that the packetization delay is always 1 millisecond. For example, a structured CEM channel of 16xDS0 has a default payload size of 128 bytes.

The payload size must be an integer of the multiple of the number of time slots for structured CEM channels.


Note Payload size configuration is optional.


Setting the Dejitter Buffer Size

To specify the size of the dejitter buffer used to compensate for the network filter, use the dejitter-buffer size command. The configured dejitter buffer size is converted from milliseconds to packets and rounded up to the next integral number of packets. Use the size argument to specify the size of the buffer, in milliseconds. The range is from 1 to 500 ms; the default is 5 ms.

Setting an Idle Pattern

To specify an idle pattern, use the idle-pattern command. The payload of each lost CESoPSN data packet must be replaced with the equivalent amount of the replacement data. The range is from 0x0 to 0xFF; the default idle pattern is 0xFF.


Note Idle pattern configuration is optional.


Enabling Dummy Mode

Dummy mode enables a bit pattern for filling in for lost or corrupted frames. To enable dummy mode, use the dummy-mode [last-frame | user-defined] command. The default is last-frame. The following is an example:

Router(config-cem)# dummy-mode last-frame 

Setting a Dummy Pattern

If dummy mode is set to user-defined, you can use the dummy-pattern pattern command to configure the dummy pattern. The range for pattern is from 0x0 to 0xFF. The default dummy pattern is 0xFF. The following is an example:

Router(config-cem)# dummy-pattern 0x55 

Shutting Down a CEM Channel

To shut down a CEM channel, use the shutdown command in CEM configuration mode. The shutdown command is supported only under CEM mode and not under the CEM class.

Configuring ATM

The following sections describe how to configure ATM features on the T1/E1 interface module:

Configuring a Clear-Channel ATM Interface

Configuring ATM IMA

Configuring a Clear-Channel ATM Interface

To configure the T1 interface module for clear-channel ATM, follow these steps:

 
Command
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 1 

Router(config)# controller {t1} slot/subslot/port

Selects the T1 controller for the port you are configuring (where slot/subslot identifies the location and /port identifies the port).

Step 2 

Router(config-controller)# atm

Configures the port (interface) for clear-channel ATM. The router creates an ATM interface whose format is atm/slot/subslot/port.

Note The slot number is always 0.

Step 3 

Router(config-controller)# end

Exits configuration mode.

To access the new ATM interface, use the interface atmslot/subslot/port command.

This configuration creates an ATM interface that you can use for a clear-channel pseudowire and other features. For more information about configuring pseudowires, see Chapter 12 "Configuring Pseudowire."

Configuring ATM IMA

Inverse multiplexing provides the capability to transmit and receive a single high-speed data stream over multiple slower-speed physical links. In Inverse Multiplexing over ATM (IMA), the originating stream of ATM cells is divided so that complete ATM cells are transmitted in round-robin order across the set of ATM links. Follow these steps to configure ATM IMA on the Cisco ASR 903 Series Router.


Note ATM IMA is used as an element in configuring ATM over MPLS pseudowires. For more information about configuring pseudowires, see Chapter 12 "Configuring Pseudowire."


To configure the ATM interface on the router, you must install the ATM feature license using the license install atm command. To activate or enable the configuration on the IMA interface, use the license feature atm command.. For more information about installing licenses, see the Software Activation Configuration Guide, Cisco IOS XE Release 3S.


Note You can create a maximum of 16 IMA groups on each T1/E1 interface module.


SUMMARY STEPS

1. enable

2. configure terminal

3. card type {t1 | e1} slot [bay]

4. controller {t1 | e1} slot/subslot/port

5. clock source internal

6. ima group group-number

7. exit

8. interface ATMslot/subslot/IMA group-number

9. no ip address

10. atm bandwidth dynamic

11. no atm ilmi-keepalive

12. exit

DETAILED STEPS

 
Command
Purpose

Step 1 

enable

Example:

Router> enable

Enables privileged EXEC mode.

Enter your password if prompted.

Step 2 

configure terminal

Example:

Router# configure terminal

Enters global configuration mode.

Step 3 

card type {t1 | e1} slot [bay]

Example:

Router(config)# card type e1 0 0

Specifies the slot and port number of the E1 or T1 interface.

Step 4 

controller {t1 | e1} slot/subslot/port
Example:
Router(config)# controller E1 0/0/4

Router(config-controller)#

Specifies the controller interface on which you want to enable IMA.

Step 5 

clock source internal
Example:
Router(config-controller)# clock 
source internal
 
        

Sets the clock source to internal.

Step 6 

ima group group-number
Example:
Router(config-controller)# 
ima-group 0 scrambling-payload
 
        

Assigns the interface to an IMA group, and set the scrambling-payload parameter to randomize the ATM cell payload frames. This command assigns the interface to IMA group 0.

Note This command automatically creates an ATM0/IMAx interface.

Step 7 

To add another member link, repeat Step 3 to Step 6.

Step 8 

exit

Example:
Router(config-controller)# exit
Router(config)#

Exits the controller interface.

Step 9 

interface ATMslot/subslot/IMA group-number

Example:

Router(config-if)# interface atm0/1/ima0

Specify the slot location and port of IMA interface group.

slot—The location of the ATM IMA interface module.

group-number—The IMA group.

The example specifies the slot number as 0 and the group number as 0.

Note To explicitly configure the IMA group ID for the IMA interface, use the optional ima group-id command. You cannot configure the same IMA group ID on two different IMA interfaces; therefore, if you configure an IMA group ID with the system-selected default ID already configured on an IMA interface, the system toggles the IMA interface to make the user-configured IMA group ID the effective IMA group ID. The system toggles the original IMA interface to select a different IMA group ID.

Step 10 

no ip address

Example:

Router(config-if)# no ip address

Disables the IP address configuration for the physical layer interface.

Step 11 

atm bandwidth dynamic

Example:

Router(config-if)# atm bandwidth dynamic

Specifies the ATM bandwidth as dynamic.

Step 12 

no atm ilmi-keepalive

Example:

Router(config-if)# no atm ilmi-keepalive

Disables the Interim Local Management Interface (ILMI) keepalive parameters.

Step 13 

exit

Example:
Router(config)# exit

Router#

Exits configuration mode.


Note The above configuration has one IMA shorthaul with two member links (atm0/0 and atm0/1).


Verifying the Interface Configuration

Besides using the show running-configuration command to display your Cisco ASR 903 Series Router configuration settings, you can use the show interfaces serial and the show controllers serial commands to get detailed information on a per-port basis for your T1/E1 interface module.

Verifying Per-Port Interface Status

To view detailed interface information on a per-port basis for the T1/E1 interface module, use the show interfaces serial command.

Router# show interfaces serial 0/0/1:0
Serial0/0/1:0 is up, line protocol is up
  Hardware is SPA-8XCHT1/E1
  Internet address is 79.1.1.2/16
  MTU 1500 bytes, BW 1984 Kbit, DLY 20000 usec, 
     reliability 255/255, txload 240/255, rxload 224/255
  Encapsulation HDLC, crc 16, loopback not set
  Keepalive not set
  Last input 3d21h, output 3d21h, output hang never
  Last clearing of ''show interface'' counters never
  Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 2998712
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 1744000 bits/sec, 644 packets/sec
  5 minute output rate 1874000 bits/sec, 690 packets/sec
     180817311 packets input, 61438815508 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     2 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 2 abort
     180845200 packets output, 61438125092 bytes, 0 underruns
     0 output errors, 0 collisions, 2 interface resets
     0 output buffer failures, 0 output buffers swapped out
     1 carrier transitions no alarm present
  Timeslot(s) Used:1-31, subrate: 64Kb/s, transmit delay is 0 flags 2
 
   

Configuration Examples

This section includes the following configuration examples:

Example: Framing and Encapsulation Configuration

Example: CRC Configuration

Example: Facility Data Link Configuration

Example: Invert Data on the T1/E1 Interface

Example: CEM Configuration

Example: ATM IMA Configuration

Example: Framing and Encapsulation Configuration

The following example sets the framing and encapsulation for the controller and interface:

! Specify the controller and enter controller configuration mode
!
Router(config)# controller t1 2/0/0
!
! Specify the framing method
!
Router(config-controller)# framing esf
!
! Exit controller configuration mode and return to global configuration mode
!
Router(config-controller)# exit
!
! Specify the interface and enter interface configuration mode
!
Router(config)# interface serial 2/0/0:0
!
! Specify the encapsulation protocol
!
Router(config-if)# encapsulation ppp
!
! Exit interface configuration mode
!
Router(config-if)# exit
!
! Exit global configuration mode
!
Router(config)# exit

Example: CRC Configuration

The following example sets the CRC size for the interface:

! Specify the interface and enter interface configuration mode
!
Router(config)# interface serial 2/0/0:0
!
! Specify the CRC size
!
Router(config-if)# crc 32
!
! Exit interface configuration mode and return to global configuration mode
!
Router(config-if)# exit
!
! Exit global configuration mode
!
Router(config)# exit

Example: Facility Data Link Configuration

The following example configures Facility Data Link:

! Specify the controller and enter controller configuration mode
!
Router(config)# controller t1 2/0/0
!
! Specify the FDL specification
!
Router(config-controller)# fdl ansi
!
! Exit controller configuration mode and return to global configuration mode
!
Router(config-controller)# exit
!
! Exit global configuration mode
!
Router(config)# exit

Example: Invert Data on the T1/E1 Interface

The following example inverts the data on the serial interface:

! Enter global configuration mode
!
Router# configure terminal
!
! Specify the serial interface and enter interface configuration mode
!
Router(config)# interface serial 2/1/3:0
!
! Configure invert data
!
Router(config-if)# invert data
!
! Exit interface configuration mode and return to global configuration mode
!
Router(config-if)# exit
!
! Exit global configuration mode
!
Router(config)# exit
 
   
 
   
 
   

Example: CEM Configuration

The following example shows how to add a T1 interface to a CEM group as a part of a SAToP pseudowire configuration. For more information about how to configure pseudowires, see Chapter 12 "Configuring Pseudowire."


Note This section displays a partial configuration intended to demonstrate a specific feature.


 
   
controller T1 0/0/0
 framing unframed
 clock source internal
 linecode b8zs
 cablelength short 110
 cem-group 0 unframed
 
   
interface CEM0/0/0
 no ip address
 cem 0
  xconnect 18.1.1.1 1000 encapsulation mpls
 
   

Example: ATM IMA Configuration

The following example shows how to add a T1/E1 interface to an ATM IMA group as a part of an ATM over MPLS pseudowire configuration. For more information about how to configure pseudowires, see Chapter 12 "Configuring Pseudowire."


Note This section displays a partial configuration intended to demonstrate a specific feature.


controller t1 4/0/0
 ima-group 0
 clock source line
 
   
interface atm4/0/ima0
 pvc 1/33 l2transport
  encapsulation aal0
  xconnect 1.1.1.1 33 encapsulation mpls