Table Of Contents
Clear Channel T3/E3 with Integrated CSU/DSU
Contents
Prerequisites for Clear Channel T3/E3 with Integrated CSU/DSU
Restrictions for Clear Channel T3/E3 with Integrated CSU/DSU
Information About Clear Channel T3/E3 with Integrated CSU/DSU
How to Configure Clear Channel T3/E3 with Integrated CSU/DSU
Configuring Clear-Channel T3
Configure the Card Type and Controller for T3
Configure DSU Mode and Bandwidth for T3
Configure Encryption Scrambling for T3
Configure a Bit-Error-Rate Test Pattern for T3
Configure Loopback for T3
Configure the Maintenance Data Link for T3
Configuring Clear-Channel E3
Configure the Card Type and Controller for E3
Configure DSU Mode and Bandwidth for E3
Configure Encryption Scrambling for E3
Configure a Bit-Error-Rate Test Pattern for E3
Configure Loopback for E3
Configure the National Bit in the G.751 Frame for E3
Verifying Clear-Channel T3/E3
Troubleshooting Tips
Configuration Example for Clear Channel T3/E3 with Integrated CSU/DSU
Additional References
Clear Channel T3/E3 with Integrated CSU/DSU
This chapter describes how to implement the Clear Channel T3/E3 with Integrated CSU/DSU feature. The feature delivers Clear Channel service as a T3/E3 pipe with bandwidth of 28x24x64k for T3 or 16x32x64 for E3. The software-configurable T3/E3 network module allows you to switch between T3 and E3 applications with a single Cisco IOS command.
The T3/E3 NM-1 network module supports a single-port T3 or E3 with an integrated channel service unit (CSU) and a data service unit (DSU). It supports High-Level Data Link Control (HDLC), PPP, and frame relay. It includes the following features:
•
Single port—universal T3/E3 version
•Clear and subrate support on both T3 and E3 modes
•Online insertion and removal (OIR) support on Cisco 3660 series and Cisco 3745 routers
•Onboard processing of Cisco Message Definition Language (MDL) and performance monitoring
•Support for scrambling and subrate can be independently or simultaneously enabled in each DSU mode
•Support for full T3 and E3 line rates
The T3/E3 NM-1 network module provides high-speed performance for advanced, fully converged networks supporting a wide array of applications and services such as security and advanced QoS for voice and video. T3/E3 and subrate T3/E3 connectivity optimizes WAN bandwidth for deploying the new applications and service delivery.
Release
|
Modification
|
12.2(11)YT
|
This feature was introduced.
|
12.2(15)T
|
This feature was integrated into this release.
|
Feature History for Clear Channel T3/E3 with Integrated CSU/DSU
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Note For more information about related Cisco IOS voice features, see the following:
•"Overview of ISDN Voice Interfaces" on page 3
•Entire Cisco IOS Voice Configuration Library—including library preface and glossary, other feature documents, and troubleshooting documentation—at http://www.cisco.com/en/US/products/ps6441/prod_configuration_guide09186a0080565f8a.html
For a list of references cited in this chapter, see the "Additional References" section.
Contents
•Prerequisites for Clear Channel T3/E3 with Integrated CSU/DSU
•Restrictions for Clear Channel T3/E3 with Integrated CSU/DSU
•Information About Clear Channel T3/E3 with Integrated CSU/DSU
•How to Configure Clear Channel T3/E3 with Integrated CSU/DSU
•Configuring Clear-Channel E3
•Configure DSU Mode and Bandwidth for E3
•Configuration Example for Clear Channel T3/E3 with Integrated CSU/DSU
•Additional References
Prerequisites for Clear Channel T3/E3 with Integrated CSU/DSU
•Perform the prerequisites that are listed in the "Prerequisites for Configuring an ISDN Voice Interface" section.
•Ensure that you have sufficient system memory (Table 6).
Table 6 Minimum Memory Requirements
Platform
|
Flash Memory
|
DRAM Memory
|
Cisco 2650
|
8 MB
|
32 MB
|
Cisco 2651XM
|
Cisco 2691
|
32 MB
|
64 MB
|
Cisco 3660 series
|
8 MB
|
64 MB
|
Cisco 3725
|
32 MB
|
128 MB
|
Cisco 3745
|
32 MB
|
128 MB
|
Restrictions for Clear Channel T3/E3 with Integrated CSU/DSU
Restrictions are described in the "Restrictions for Configuring ISDN Voice Interfaces" section on page 4.
Information About Clear Channel T3/E3 with Integrated CSU/DSU
Note General information about ISDN voice interfaces is presented in the "Information About ISDN Voice Interfaces" section on page 4.
All supported platforms are capable of supporting line-rate performance, but impose varying levels of CPU overhead and therefore affect overall platform performance. Table 7 shows recommended branch-office positioning.
Table 7 T3/E3 NM-1 Branch Office Positioning and Support Comparison
Platform
|
Recommended Positioning
|
Supported T3/E3 Modes
|
Type of Service
|
Branch Office Size
|
Cisco 2650
|
Subrate T3/E3
|
Small to medium offices
|
1
|
Cisco 2651XM
|
Cisco 2691
|
Subrate T3/E3
|
Small to medium offices
|
1
|
Cisco 3660 series
|
Subrate and full-rate T3/E3
|
Large and regional offices
|
1
|
Cisco 3725
|
Subrate and full-rate T3/E3
|
Medium and large offices
|
1
|
Cisco 3745
|
Subrate and full-rate T3/E3
|
Medium, large, and regional offices
|
2
|
How to Configure Clear Channel T3/E3 with Integrated CSU/DSU
This section contains the following procedures:
•Configuring Clear-Channel T3
•Configuring Clear-Channel E3
•Verifying Clear-Channel T3/E3
Configuring Clear-Channel T3
This section contains the following procedures:
•Configure the Card Type and Controller for T3
•Configure DSU Mode and Bandwidth for T3
•Configure Encryption Scrambling for T3
•Configure a Bit-Error-Rate Test Pattern for T3
•Configure Loopback for T3
•Configure the Maintenance Data Link for T3
Configure the Card Type and Controller for T3
To configure the card type and controller for T3, perform the following steps.
Note•When the clear-channel T3/E3 network module is used for the first time, the running configuration does not show the T3/E3 controller and its associated serial interface. Use the show version command to learn if the router recognized the T3/E3 card and was able to initialize the card properly. After the card type is configured for the slot, the respective controller and serial interfaces appear in the running configuration. See the "Additional References" section.
•The autoconfig/setup utility does not support configuring the card type for the T3/E3 network module.
SUMMARY STEPS
1. enable
2. configure terminal
3. card type t3
4. controller t3
5. framing
6. cablelength
7. clock source
8. exit
DETAILED STEPS
| |
Command or Action
|
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 t3 slot
Example:
Router(config)# card type t3 1
|
Configures the card type on the T3 controller for the designated slot.
Note By default, the T3 controller does not show up in the show running-config output.
|
Step 4
|
controller t3 slot/port
Example:
Router(config)# controller t3 1
|
Specifies the T3 controller and enters controller configuration mode for the specified slot/port.
|
Step 5
|
framing {c-bit | m23}
Example:
Router(config-controller)# framing c-bit
|
Specifies the T3 framing type. Keywords are as follows:
•c-bit—C-bit framing
•m23—M23 framing
|
Step 6
|
cablelength feet
Example:
Router(config-controller)# cablelength 250
|
Specifies the distance from the routers to the network equipment.
|
Step 7
|
clock source {internal | line}
Example:
Router(config-controller)# clock source
line
|
Selects the clock source. Keywords are as follows:
•internal—Internal clock source (T3 default)
•line—Network clock source (E3 default)
|
Step 8
|
Example:
Router(config-controller)# exit
|
Exits the current mode.
|
Configure DSU Mode and Bandwidth for T3
To configure DSU mode and bandwidth for T3, perform the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface serial
4. dsu mode
5. dsu bandwidth
6. exit
DETAILED STEPS
| |
Command or Action
|
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
|
interface serial slot/port
Example:
Router(config)# interface serial 1/1
|
Enters interface configuration mode for the specified slot/port.
|
Step 4
|
dsu mode {0 | 1 | 2 | 3 | 4}
Example:
Router(config-if)# dsu mode 0
|
Specifies the interoperability mode used by a T3 controller—that is, to what the T3 controller connects. Keywords are as follows:
•0—Another T3 controller or a Digital Link DSU (DL3100) (default)
•1—Kentrox DSU
•2—Larscom DSU
•3—Adtran T3SU 300
•4—Verilink HDM 2182
|
Step 5
|
dsu bandwidth kbps
Example:
Router(config-if)# dsu bandwidth 44210
|
Specifies the maximum allowable bandwidth, in kbps. Range: 1 to 44210.
Note The real (actual) vendor-supported bandwidth range is 75 to 44210 kbps. See Table 6.
|
Step 6
|
Example:
Router(config-if)# exit
|
Exits the current mode.
|
Configure Encryption Scrambling for T3
To configure encryption scrambling for T3, perform the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface serial
4. scramble
5. exit
DETAILED STEPS
| |
Command or Action
|
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
|
interface serial slot/port
Example:
Router(config)# interface serial 1/1
|
Enters interface configuration mode for the specified slot/port.
|
Step 4
|
scramble
Example:
Router(config-if)# scramble
|
Enables the scrambling of the payload. Default: off.
|
Step 5
|
Example:
Router(config-if)# exit
|
Exits the current mode.
|
Configure a Bit-Error-Rate Test Pattern for T3
To configure a bit-error-rate test pattern for T3, perform the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. controller t3
4. bert pattern
5. no bert
6. exit
DETAILED STEPS
| |
Command or Action
|
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 t3 slot/port
Example:
Router(config)# controller t3 1/1
|
Enters controller configuration mode for the specified slot/port.
|
Step 4
|
bert pattern {2^23 | 2^20 | 2^15 | 1s | 0s
| alt-0-1} interval time
Example:
Router(config-controller)# bert pattern
2^20 interval 10000
|
Configures a bit-error-rate test pattern. Keywords and arguments are as follows:
•2^23—Pseudorandom 0.151 test pattern, 8,388,607 bits long
•2^20—Pseudorandom 0.153 test pattern, 1,048,575 bits long
•2^15—Pseudorandom 0.151 test pattern, 32,768 bits long
•1s—Repeating pattern of ones (...111...)
•0s—Repeating pattern of zeros (...000...)
•alt-0-1—Repeating pattern of alternating zeros and ones (...01010...)
•interval time—Duration of the BER test, in minutes.
|
Step 5
|
no bert
Example:
Router(config-controller)# no bert
|
Disables the BERT test pattern.
|
Step 6
|
exit
Example:
Router(config-controller)# exit
|
Exits the current mode.
|
Configure Loopback for T3
To configure loopback for T3, perform the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. controller t3
4. loopback
5. no loopback
6. exit
DETAILED STEPS
| |
Command or Action
|
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 t3 slot/port
Example:
Router(config)# controller t3 1/1
|
Enters controller configuration mode for the specified slot/port.
|
Step 4
|
loopback {local | network {line | payload}
| remote}
Example:
Router(config-controller)# loopback local
|
Loops the T3 line toward the line and back toward the router. Keywords are as follows:
•local—Loops the data back toward the router and sends an alarm-indication signal (AIS) out toward the network. On a dual port card, it is possible to run channelized on one port and primary rate on the other port.
•network {line | payload}—Sets loopback toward the network before going through the framer (line) or after going through the framer (payload).
•remote—Sends a far-end alarm control (FEAC) request to the remote end requesting that it enter into a network line loopback. FEAC requests (and therefore remote loopbacks) are possible only when the T3 is configured for C-bit framing. M23 format does not support remote loopbacks.
|
Step 5
|
no loopback
Example:
Router(config-controller)# no loopback
|
Removes the loop.
|
Step 6
|
Example:
Router(config-controller)# exit
|
Exits the current mode.
|
Configure the Maintenance Data Link for T3
To configure the maintenance date link for T3, perform the following steps.
Note This configuration information is applicable only to C-bit parity T3.
SUMMARY STEPS
1. enable
2. configure terminal
3. controller t3
4. mdl
5. exit
DETAILED STEPS
| |
Command or Action
|
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 t3 slot/port
Example:
Router(config)# controller t3 1/1
|
Enters controller configuration mode for the specified slot/port.
|
Step 4
|
mdl {transmit {path | idle-signal |
test-signal} | string {eic | lic | fic |
unit | pfi | port | generator} string}
Example:
Router(config-controller)# mdl transmit
path
|
Configures the MDL message. Keywords and arguments are as follows:
•transmit path—Enables transmission of the MDL path message.
•transmit idle-signal—Enables transmission of the MDL idle signal message.
•transmit test-signal—Enables transmission of the MDL test signal message.
•string eic string—Equipment identification code (EIC); can be up to 10 characters.
•string lic string—Location identification code (LIC); can be up to 11 characters.
•string fic string—Frame identification code (FIC); can be up to 10 characters.
•string unit string—Unit identification code (UIC); can be up to 6 characters.
•string pfi string—Facility identification code (PFI) sent in the MDL path message; can be up to 38 characters.
•string port string—Port number string sent in the MDL idle signal message; can be up to 38 characters.
•string generator string—Generator number string sent in the MDL test signal message; can be up to 38 characters.
|
Step 5
|
Example:
Router(config-controller)# exit
|
Exits the current mode.
|
Configuring Clear-Channel E3
This section contains the following procedures:
•Configure the Card Type and Controller for E3
•Configure DSU Mode and Bandwidth for T3
•Configure Encryption Scrambling for E3
•Configure a Bit-Error-Rate Test Pattern for E3
•Configure Loopback for E3
•Configure the National Bit in the G.751 Frame for E3
Configure the Card Type and Controller for E3
To configure the card type and controller for E3, perform the following steps.
Note The autoconfig/setup utility does not support configuring the card type for the T3/E3 network module.
SUMMARY STEPS
1. enable
2. configure terminal
3. card type e3
4. controller e3
5. framing
6. clock source
7. exit
DETAILED STEPS
| |
Command or Action
|
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 e3 slot
Example:
Router(config)# card type e3 1
|
Configures the card type on the E3 controller for the designated slot.
Note By default, the E3 controller does not show up in the show running-config output.
|
Step 4
|
controller e3 slot/port
Example:
Router(config)# controller e3 1
|
Enters controller configuration mode for the specified slot/port.
|
Step 5
|
framing {bypass | g751}
Example:
Router(config-controller)# framing bypass
|
Specifies the framing type. Keywords are as follows:
•bypass—G.751 framing is bypassed
•g751—G.751 is the E3 framing type (default)
|
Step 6
|
clock source {internal | line}
Example:
Router(config-controller)# clock source
line
|
Selects the clock source. Keywords are as follows:
•internal—Internal clock source (T3 default)
•line—Network clock source (E3 default)
|
Step 7
|
Example:
Router(config-controller)# exit
|
Exits the current mode.
|
Configure DSU Mode and Bandwidth for E3
To configure DSU mode and bandwidth for E3, perform the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface serial
4. dsu mode
5. dsu bandwidth
6. exit
DETAILED STEPS
| |
Command or Action
|
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
|
interface serial slot/port
Example:
Router(config)# interface serial 1/1
|
Enters interface configuration mode for the specified slot/port.
|
Step 4
|
dsu mode {0 | 1}
Example:
Router(config-if)# dsu mode 0
|
Specifies the interoperability mode used by an E3 controller—that is, to what the E3 controller connects. Keywords are as follows:
•0—(default) Another E3 controller or a digital link DSU (DL3100)
•1—Kentrox DSU
|
Step 5
|
dsu bandwidth kbps
Example:
Router(config-if)# dsu bandwidth 34010
|
Specifies the maximum allowable bandwidth, in kbps. Range: 22 to 34010.
Note The real (actual) vendor-supported bandwidth range is 358 to 34010 kbps. See Table 6.
|
Step 6
|
Example:
Router(config-if)# exit
|
Exits the current mode.
|
Configure Encryption Scrambling for E3
To configure encryption scrambling for E3, perform the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface serial
4. scramble
5. exit
DETAILED STEPS
| |
Command or Action
|
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
|
interface serial slot/port
Example:
Router(config)# interface serial 1/1
|
Enters interface configuration mode for the specified slot/port.
|
Step 4
|
scramble
Example:
Router(config-if)# scramble
|
Enables the scrambling of the payload. Default: off.
|
Step 5
|
Example:
Router(config-if)# exit
|
Exits the current mode.
|
Configure a Bit-Error-Rate Test Pattern for E3
To configure a bit-error-rate test pattern for E3, perform the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. controller t3
4. bert pattern
5. no bert
6. exit
DETAILED STEPS
| |
Command or Action
|
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 e3 slot/port
Example:
Router(config)# controller e3 1/0
|
Enters controller configuration mode for the specified slot/port.
|
Step 4
|
bert pattern {2^23 | 2^20 | 2^15 | 1s | 0s
| alt-0-1} interval time
Example:
Router(config-controller)# bert pattern
2^20 interval 1440
|
Enables a bit-error-rate (BER) test pattern on a T1 or E1 line, and sets the length of the test pattern and duration of the test. Keywords and arguments are as follows:
•2^23—Pseudorandom 0.151 test pattern, 8,388,607 bits long
•2^20—Pseudorandom 0.153 test pattern, 1,048,575 bits long
•2^15—Pseudorandom 0.151 test pattern, 32,768 bits long
•1s—Repeating pattern of ones (...111...)
•0s—Repeating pattern of zeros (...000...)
•alt-0-1—Repeating pattern of alternating zeros and ones (...01010...)
•interval time—Duration of the BER test, in minutes
|
Step 5
|
no bert
Example:
Router(config-controller)# no bert
|
Disables the BER test pattern.
|
Step 6
|
exit
Example:
Router(config-controller)# exit
|
Exits the current mode.
|
Configure Loopback for E3
To configure loopback for E3, perform the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. controller e3
4. loopback
5. no loopback
6. exit
DETAILED STEPS
| |
Command or Action
|
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 e3 slot/port
Example:
Router(config)# controller e3 1/1
|
Enters controller configuration mode for the specified slot/port.
|
Step 4
|
loopback {local | network {line |
payload}}
Example:
Router(config-controller)# loopback local
|
Loops the E3 line toward the line and back toward the router. Keywords are as follows:
•local—Loops the data back toward the router and sends an AIS signal out toward the network.
•network {line | payload}—Sets loopback toward the network before going through the framer (line) or after going through the framer (payload).
|
Step 5
|
no loopback
Example:
Router(config-controller)# no loopback
|
Removes the loop.
|
Step 6
|
Example:
Router(config-controller)# exit
|
Exits the current mode.
|
Step 7
|
Example:
Router(config)# exit
|
Exits the current mode.
|
Configure the National Bit in the G.751 Frame for E3
To configure the national bit in the G.751 frame for E3, perform the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. controller e3
4. national bit
5. exit
DETAILED STEPS
| |
Command or Action
|
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 e3 slot/port
Example:
Router(config)# controller e3 1/1
|
Enters controller configuration mode for the specified slot/port.
|
Step 4
|
national bit {1 | 0}
Example:
Router(config-controller)# national bit 1
|
Sets the E3 national bit in the G.751 frame used by the E3 controller. Valid values: 0 and 1. Default: 1.
|
Step 5
|
Example:
Router(config-controller)# exit
|
Exits the current mode.
|
Verifying Clear-Channel T3/E3
To verify clear-channel T3/E3, perform the following steps (listed alphabetically).
SUMMARY STEPS
1. show controllers
2. show interfaces serial
3. show isdn status
4. show running-config
5. show version
DETAILED STEPS
Step 1 show controllers
Use this command to display information about the specified port, connector, or interface card number (location of voice module) or slot/port (location of voice network module and VIC).
Step 2 show interfaces serial
Use this command to display information about a serial interface.
Step 3 show isdn status
Use this command to display the status of all ISDN interfaces, including active layers, timer information, and switch-type settings.
Step 4 show running-config
Use this command to display basic router configuration.
Step 5 show version
Use this command to display whether the router recognized the T3/E3 card and was able to initialize the card properly. Lists the hardware interfaces and controllers present in the router. You should find "1 Subrate T3/E3 port(s)".
Router uptime is 2 hours, 6 minutes
System returned to ROM by power-on
System image file is "flash:c3725-i-mz"
cisco 3725 (R7000) processor (revision 0.4) with 111616K/19456K bytes of memory.
Processor board ID 12345678901
R7000 CPU at 240Mhz, Implementation 39, Rev 3.3, 256KB L2 Cache
X.25 software, Version 3.0.0
Primary Rate ISDN software, Version 1.1
2 FastEthernet/IEEE 802.3 interface(s)
1 Serial network interface(s)
2 Channelized T1/PRI port(s)
DRAM configuration is 64 bits wide with parity disabled.
55K bytes of non-volatile configuration memory.
15680K bytes of ATA System CompactFlas (Read/Write)
Configuration register is 0x0
Troubleshooting Tips
Set Loopbacks
•Use T3/E3 local loopback to ensure that the router and the T3/E3 network module are working properly. The controller clock source should be configured to "internal."
•Use T3/E3 network loopback and remote loopback to diagnose problems with cables between the T3/E3 controller and the central switching office at the link level. For this diagnostic setup to work, if the network module is looped toward the network, the network module must be configured with the clock source as "line."
Run Bit Error Rate Test
•The network module contains onboard BERT circuitry. With this circuitry present, the software can send and detect a programmable pattern that is compliant with CCITT/ITU pseudorandom and repetitive test patterns. BERT allows you to test cables and signal problems in the field.
•When a BERT is running, your system expects to receive the same pattern that it is sending. To help ensure this, two common options are available.
–Use a loopback somewhere in the link or network.
–Configure remote testing equipment to send the same BERT pattern at the same time.
Configuration Example for Clear Channel T3/E3 with Integrated CSU/DSU
This example shows the running configuration of a router whose E3 (slot1/0) interface is configured to use G.751 framing and a network (line, or network, is the E3 default) clock source. Note that the bandwidth of the interface is configured to 34010 kbps.
Router# show running-config
Building configuration...
%AIM slot 0 doesn't exist
Current configuration :1509 bytes
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
voice call carrier capacity active
mta receive maximum-recipients 0
interface FastEthernet0/0
ip address 10.0.145.34 255.255.255.0
interface FastEthernet0/1
ip address 172.27.27.2 255.255.255.0
Additional References
General ISDN References
•"ISDN Features Roadmap" on page 1—Describes how to access Cisco Feature Navigator; also lists and describes, by Cisco IOS release, ISDN features for that release
•"Overview of ISDN Voice Interfaces" on page 3—Describes relevant underlying technology; lists related documents, standards, MIBs, and RFCs; and describes how to obtain technical assistance
•"Additional References" section—Lists additional ISDN references
