Configuration Tasks
This section describes how to configure the following T1/E1 interface modules for the chassis.
T1/E1 Interface Module |
Part Number |
---|---|
16-port T1/E1 Interface Module |
A900-IMA16D |
8-portT1/E1 Interface Module |
A900-IMA8D |
32-Port T1/E1 Interface Module |
A900-IMA32D |
This section includes the following topics:
Limitations
This section describes the software limitations that apply when configuring the T1/E1 interface module.
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The following interface modules are not supported on the RSP3 module:
-
16-port T1/E1 interface module
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8-portT1/E1 interface module
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32-portT1/E1 interface module
-
-
The configure replace command is not supported on the T1/E1 interface modules.
-
The chassis does not support more than 16 IMA groups on each T1/E1 interface module.
-
The chassis only supports the following BERT patterns: 2^11, 2^15, 2^20-O153, and 2^20-QRSS.
-
L2TPv3 encapsulation is not supported.
-
Replacing a configured interface module with a different interface module in the same slot is not supported.
-
Mixed configurations of features are not supported on the same port.
-
The Payload calculation per unit for T1/E1 interface module is:
-
Framed E1 / T1 with no. of time Slots less than 4 –> Payload = 4 x no. of time slots.
-
Framed E1 / T1 with no. of Time Slots greater than or equal 4 -> Payload = 2 x no. of time slots.
-
Unframed T1, C11 –> Payload = 48 (2 x 24 (all slots)).
-
Unframed E1, C12 –> Payload = 64 (2 x32(all slots))
-
-
Channelization is not supported for serial interfaces. However, channelization is supported for CEM at the DS0 level.
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
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:
Procedure
Step 1 |
configure terminal Example:
Enters global configuration mode. |
Step 2 |
card type {e1 | t1 } slot/subslot Example:
Sets the serial mode for the interface module:
|
Step 3 |
exit Example:
Exits configuration mode and returns to the EXEC command interpreter prompt. |
Enabling T1 Controller
Note |
T1/T3 or E1/E3 does not require any license. |
To enable T1 controller:
enable
configure terminal
controller mediatype 0/4/0
mode t1
end
Configuring the Controller
To create the interfaces for the T1/E1 interface module, complete these steps:
Procedure
Step 1 |
configure terminal Example:
Enters global configuration mode. |
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Step 2 |
controller {t1 | e1 } slot/subslot/port Example:
Selects the controller to configure and enters controller configuration mode.
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Step 3 |
clock source {internal | line } Example:
Sets the clock source.
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Step 4 |
linecode {ami | b8zs | hdb3 } Example:
Selects the linecode type.
|
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Step 5 |
For T1 Controllers: Example:
Example:
Example:
Example:
Example:
Selects the framing type.
|
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Step 6 |
cablelength {long | short } Example:
To fine-tune the pulse of a signal at the receiver for an E1 cable, use the cablelength command in controller configuration mode. |
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Step 7 |
exit Example:
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
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.
Procedure
Step 1 |
configure terminal Example:
Enters global configuration mode. |
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Step 2 |
controller {t1 | e1 } slot/subslot/port Example:
Selects the controller to configure.
|
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Step 3 |
For T1 controllers Example:
Example:
Example:
Example:
Example:
Example:
Sets the framing on the interface.
|
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Step 4 |
exit Example:
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
Setting an IP Address
To set an IP address for the serial interface, complete these steps:
You can also set an IP address using an IMA or CEM configuration.
Procedure
Step 1 |
interface serial 0/subslot/port:channel-group Example:
Selects the interface to configure from global configuration mode.
|
Step 2 |
ip address address mask Example:
Sets the IP address and subnet mask.
|
Step 3 |
exit Example:
Exits configuration mode and returns to the EXEC command interpreter prompt. |
What to do next
Note |
IPV4 routing protocols, such as eigrp , ospf , bgp , and rip , are supported on serial interfaces. |
Configuring Encapsulation
When traffic crosses a WAN link, the connection needs a Layer 2 protocol to encapsulate traffic.
Note |
L2TPv3 encapsulation is not supported. |
To set the encapsulation method, use the following commands:
Procedure
Step 1 |
configure terminal Example:
Example:
Enters global configuration mode. |
Step 2 |
interface serial 0/subslot/port:channel-group Example:
Example:
Selects the interface to configure from global configuration mode.
|
Step 3 |
encapsulation {hdlc | ppp } Example:
Set the encapsulation method on the interface.
|
Step 4 |
exit Example:
Exits configuration mode and returns to the EXEC command interpreter prompt. |
Verifying Encapsulation
Use the show interfaces serial command to verify encapsulation on the interface:
Router# show interfaces serial
0/0/1:0
Serial0/0/1:0 is up, line protocol is up
Hardware is Multichannel T1
MTU 1500 bytes, BW 1536 Kbit/sec, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC
, crc 16, loopback not set
Keepalive set (10 sec)
Last input 00:00:01, output 00:00:02, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
60 packets input, 8197 bytes, 0 no buffer
Received 39 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
64 packets output, 8357 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 unknown protocol drops
0 output buffer failures, 0 output buffers swapped out
1 carrier transitions
Configuring the CRC Size for T1 Interfaces
All T1/E1 serial interfaces use a 16-bit cyclic redundancy check (CRC) by default, but also support a 32-bit CRC. CRC is an error-checking technique that uses a calculated numeric value to detect errors in transmitted data. The designators 16 and 32 indicate the length (in bits) of the frame check sequence (FCS). A CRC of 32 bits provides more powerful error detection, but adds overhead. Both the sender and receiver must use the same setting.
CRC-16, the most widely used CRC throughout the United States and Europe, is used extensively with WANs. CRC-32 is specified by IEEE 802 and as an option by some point-to-point transmission standards.
To set the length of the cyclic redundancy check (CRC) on a T1 interface, use these commands:
Procedure
Step 1 |
configure terminal Example:
Example:
Enters global configuration mode. |
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Step 2 |
interface serial 0/subslot/port:channel-group Example:
Example:
Selects the interface to configure from global configuration mode.
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Step 3 |
crc {16 | 32 } Example:
Selects the CRC size in bits.
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Step 4 |
exit Example:
Exits configuration mode and returns to the EXEC command interpreter prompt. |
Verifying the CRC Size
Use the show interfaces serial command to verify the CRC size set on the interface:
Router# show interfaces serial 0/0/1:0
Serial0/0/1:0 is up, line protocol is up
Hardware is Multichannel T1
MTU 1500 bytes, BW 1536 Kbit/sec, DLY 20000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation HDLC, crc 16
, loopback not set
Keepalive set (10 sec)
Last input 00:00:01, output 00:00:02, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
60 packets input, 8197 bytes, 0 no buffer
Received 39 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
64 packets output, 8357 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 unknown protocol drops
0 output buffer failures, 0 output buffers swapped out
1 carrier transitions
Configuring a Channel Group
Follow these steps to configure a channel group:
Procedure
Step 1 |
configure terminal Example:
Enters global configuration mode. |
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Step 2 |
controller {t1 | e1 } slot/subslot/port Example:
Select the controller to configure and enter global configuration mode. |
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Step 3 |
channel-group [t1 | e1 ] number {timeslots range | unframed } [speed {56 | 64 }] Example:
Defines the time slots that belong to each T1 or E1 circuit.
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Step 4 |
exit Example:
Exits configuration mode and returns to the EXEC command interpreter prompt. |
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 |
---|---|
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
The following sections describe how to set loopbacks:
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 |
---|---|
configure terminal |
Enters global configuration mode. |
controller e1 slot /subslot /port |
Select the E1 controller and enter controller configuration mode.The slot number is always 0. |
loopback diag |
Set a diagnostic loopback on the E1 line. |
loopback network {line | payload } |
Set a network payload loopback on the E1 line. |
end |
Exit configuration mode when you have finished configuring the controller. |
Setting a Loopback on the T1 Controller
You can use the following loopback commands on the T1 controller in global configuration mode:
Task |
Command |
---|---|
controller t1 slot /subslot /port |
Selects the T1 controller and enter controller configuration mode The slot number is always 0. |
loopback diag |
Sets a diagnostic loopback on the T1 line. |
loopback local {line | payload } |
Sets a local loopback on the T1 line. You can select to loopback the line or the payload. |
loopback remote iboc |
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. |
end |
Exits configuration mode when you have finished configuring the controller. |
Note |
To remove a loopback, use the no loopback command. |
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. |
Runing Bit Error Rate Testing
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:
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Use a loopback somewhere in the link or network
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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 |
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---|---|---|---|
controller {e1 | t1 } slot/subslot/port |
Selects the E1 or T1 controller and enters controller configuration mode. The slot number is always 0. |
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bert pattern 0s | 1s | 2^11 | 2^15 | 2^20-O153 | 2^20-QRSS | 2^23 | alt-0-1 } interval minutes |
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.
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end |
Exit configuration mode when you have finished configuring the controller. |
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show controllers {e1 | t1 } slot/subslot/port |
Displays the BERT results. |
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. |
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 |
---|---|
show controllers {e1 | t1 } [slot/port-adapter/port/e1-line ] [brief |
Displays the status of the E1 or T1 controller. |
show interface serial slot/subslot/port |
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. |
clear counters serial slot/subslot/port |
Clears the interface counters |
Note |
To change the T1/E1 card type configuration, use the no card type command and reload the router. |
AIS on Core Failure
AIS stands for Alarm Indication Signal. Prior to Cisco IOS XE Fuji Release 16.7.1, the PDH AIS alarms were generated only when the CE would go down and an event was set in the CEM control-word by the remote provider edge (PE). AIS alarms were not generated when the pesudowire went down. Now, AIS alarm are generated when the pesudowire goes down.
This feature is only supported on the Cisco ASR 900 RSP2 module, for 8-port T1/E1 and 16-port T1/E1 interface modules and only for unframed E1 mode (SAToP) type.
Limitations of AIS
-
AIS is not supported on CESoP and CEM over UDP.
-
AIS is not supported on T1 mode. It is only supported on E1 mode.
-
AIS is not supported on the 4-port OC3/STM-1 (OC-3) interface module (IM) and 32-port T1/E1 IM.
-
AIS is supported only for MPLS core.
-
AIS is not supported in pseudowire HSPW mode, when graceful-restart command is enabled.
-
Removing the MPLS IP address from the core interfaces results in a delay of 10-12 minutes to notify the peer end. This depends on the negotiated forwarding hold timer between the routers, which is the least value of the configured LDP GR forwarding hold timer of the two routers.
-
Supported CEM class range of de-jitter buffer size is between 1 to 32 ms.
-
If the shutdown unpowered command is used to shut down the IM, an OIR must be performed to trigger the AIS alarms..
Core Failure Event Detection
AIS configuration is used to detect core defects. The core failure is detected in the following events:
-
Shutdown of the PE controller or tug level.
-
Removing the cross-connect feature.
-
Removal of Gigabit Ethernet configuration, CEM configuration, controller configuration, or OSPF configuration.
-
Shut on OSPF, CEM group, cross-connect, or Gigabit Ethernet interface.
-
CE1 controller shut—AIS alarm is seen on the remote CE.
-
PE1 controller shut—AIS alarm is seen on the remote CE.
-
PE1 core shut—AIS alarm is seen on both the CEs.
-
PE2 core shut—AIS alarm is seen on both the CEs.
-
Pesudowire down—AIS alarm is seen on both the CEs.
-
Core IGP down—AIS alarm is seen on both the CEs.
-
Core LDP down—AIS alarm is seen on both the CEs.
Configuring AIS for Core Failure
When you enable the AIS, Plesiochronous Digital Hierarchy (PDH) AIS alarm is supported for core failure events on the 8-port T1/E1 and 16-port T1/E1 interface modules. When a core failure is detected due to any event, core flap flag is updated and the core flap event sends an event, which asserts an AIS. When the AIS is not enabled, core failure events are ignored.
Use the following procedure to enable AIS:
Router> enable
Router#configure terminal
Router(config)#controller t1 0/1/2
Router(config-controller)#ais-core-failure
Verifying AIS Configuration
Use the show run | sec command to verify the configuration of AIS:
Router(config-controller)#show run | sec 0/3/0
controller E1 0/3/0
ais-core-failure
framing unframed
cem-group 30 unframed
interface CEM0/3/0
Example: AIS Trigger
The following example shows a sample configuration of a controller O/P when an AIS is triggered:
Router#show controller e1 0/2/1
E1 0/2/1 is down.
Applique type is A900-IMA16D
Cablelength is Unknown
Transmitter is sending remote alarm.
Receiver is getting AIS. <<<<<<<<<<<<< This is AIS alarm received
ais-shut is not set
alarm-trigger is not set
Framing is crc4, Line Code is HDB3, Clock Source is Line.
BER thresholds: SF = 10e-5 SD = 10e-5
International Bit: 1, National Bits: 11111
Data in current interval (0 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
1 Near-end path failures, 0 Far-end path failures, 0 SEF/AIS Secs