Cisco 10000 Series Router Line Card Configuration Guide - 6-Port Channelized T3 Line Card Configuration [Cisco 10000 Series Routers]

Table Of Contents

6-Port Channelized T3 Line Card Configuration

Software Support

Checking Hardware and Software Compatibility

Default Values

Interface Syntax

Interface Configuration Sample

Unchannelized T3 Commands

Entering Controller Configuration Mode for T3

Configuring a T3 Interface as Unchannelized

Implementing Subrate T3

Setting the Framing Type

Specifying the DSU Mode

Enabling Scrambling

Specifying an Idle Character

Running a BER Test

Channelized T3 Commands

Entering Controller Configuration Mode for T3

Configuring a T3 Interface as Channelized

Specifying the Cable Length

Setting the Framing Type

Entering MDL Messages

Specifying the Idle Pattern

Setting the Clock Source

Configuring Loopback Mode

Running Equipment Loopbacks

Channel-Group Command for DS0 Timeslots and T1s

Channelized T1 Commands

Setting the Framing Format

Controlling Yellow Alarms

Setting the Clock Source

Configuring FDL

Configuring a BER Test

Configuring Loopback Mode

6-Port Channelized T3 Line Card Configuration

This chapter describes procedures for configuring the Cisco 10000 series 6-Port Channelized T3 line card, hereafter known as the 6-Port Channelized T3 line card.

The 6-Port Channelized T3 line card provides the Cisco 10000 series routers with six DS3 ports of high-density T3 service.

This chapter contains the following sections:

•Software Support

•Default Values

•Interface Syntax

•Interface Configuration Sample

•Unchannelized T3 Commands

•Channelized T3 Commands

•Channel-Group Command for DS0 Timeslots and T1s

•Channelized T1 Commands

Software Support

Table 8-1 shows the minimum Cisco IOS release on each release train that supports the 6-Port Channelized T3 line card.

Table 8-1 6-Port Channelized T3 Line Card Software Support

Required PRE

Minimum Cisco IOS Releases

PRE1

Cisco IOS Release 12.0(9)SL and later releases of Cisco IOS 12.0SL
Cisco IOS Release 12.0(17)ST and later releases of Cisco IOS 12.0ST
Cisco IOS Release 12.0(22)S and later releases of Cisco IOS 12.0S
Cisco IOS Release 12.2(8)BZ and later releases of Cisco IOS 12.2BZ

PRE2

Cisco IOS Release 12.2(15)BX and later releases of Cisco IOS 12.2BX
Cisco IOS Release 12.3(7)XI and later releases of Cisco IOS 12. XI
Cisco IOS Release 12.2(28)SB and later releases of Cisco IOS 12.2SB

Checking Hardware and Software Compatibility

The PRE installed in the Cisco 10000 series router chassis must support the Cisco IOS software running on the router. Use the show version command to check the PRE version installed.

To see if a feature is supported by a Cisco IOS release, to locate the software document for that feature, or to check the minimum software requirements of Cisco IOS software with the hardware installed on your router, Cisco maintains the Software Advisor tool on Cisco.com at http://www.cisco.com/pcgi-bin/Support/CompNav/Index.pl

This tool does not verify whether line cards within a system are compatible, but does provide the minimum Cisco IOS requirements for individual hardware line cards, modules, or options.

You must be a registered user on Cisco.com to access this tool.

Default Values

Table 8-2 lists default values for the 6-Port Channelized T3 line card and indicates which values apply to which line speeds. This table also includes the command used for modifying a default value and indicates whether a value needs to be the same (or opposite) on the remote end of the connection.
Table 8-2 6-Port Channelized T3 Line Card Default Values
Command Name

Default Setting

Command Syntax

Remote Side Setting

DS 0

T1

Ch T3

Unch T3

Controller Configuration Mode
cable length

249
cablength feet
—

x

x
channelized

channelized
[no] channelized
—

x

x
clock source

internal
clock source [line | 
internal]
At least one side set to internal

x

x
T1 clock source

internal
t1 t1-number clock 
source [line | 
internal]
At least one side set to internal

x
framing

auto-detect
framing [c-bit | m23 
| auto-detect]
Same

x
T1 framing

esf
t1 t1-number framing 
[esf | sf [hdlc-idle 
{0x7E | 0xFF}]]
Same

x
idle pattern

0X7e (flags)
idle pattern [0x0 to 
0xFF]
Same

x
Interface Configuration Mode
crc (cyclical redundancy check)

16
[no] crc [16 | 32]
Same

x

x
DSU bandwidth

44,210
dsu bandwidth 
bandwidth
Same

x
DSU mode

cisco
dsu mode mode
Same

x
encapsulation

HDLC
encapsulation [hdlc 
| ppp | frame-relay]
Same

x

x
framing

c-bit
framing [c-bit | 
m13]
Same

x
idle character

flags (0x7e)
idle character 
[flags | marks]
Same

x
keepalive

keepalive (10 sec)
keepalive
Same

x

x
mtu (maximum transmission unit)

4470
mtu size
Same

x

x
scramble

No scrambling
[no] scramble
Same

x
Interface Syntax

To specify an interface number in a configuration command, use the syntax in Table 8-3 to identify interfaces on the 6-Port Channelized T3 line card.

Table 8-3 6-Port Channelized T3 Line Card Interface Syntax

Type of Interface

Slot

Subslot

Port (T3 Number)

T1 Number

Channel Group Number

Unchannelized

1 to 8/

0/

0 to 5

—

—

Channelized

1 to 8/

0/

0 to 5/

1 to 28

0 to 23

Examples:

•Modifying T1 interface 6 in controller configuration mode:
Router(config)# controller t3 2/0/0
Router(config-controller)# t1 6 command
•Modifying T1 interface 6, channel group number 8 in interface configuration mode:
Router(config)# interface serial 2/0/0/6:8
Router(config-if)
Interface Configuration Sample

Each T3 controller can be configured as a single T3 interface (full or subrate), as 28 T1 interfaces, or as an even larger number of fractional T1s. The following procedure walks you through the basic steps for creating full-rate and subrate T3 interfaces, as well as T1 and fractional T1 interfaces:

Step 1 Create an interface. In the following examples, each type of interface is created in a different T3 controller (2/0/0 through 2/0/3).

Full-Rate T3 Interface

a. Enter controller configuration mode.
Router(config)# controller t3 2/0/0
Router(config-controller)#
b. To create a full-rate T3 interface, you must eliminate the T1 interfaces by entering the no channelized command.
Router(config-controller)# no channelized
Router(config-controller)# exit
Router(config)#
c. Go to interface configuration mode:
Router(config)# interface serial 2/0/0
d. You can now continue to Step 2.

Subrate T3 Interface

a. Enter controller configuration mode.
Router(config)# controller t3 2/0/1
Router(config-controller)#
b. To create a subrate T3 interface, first create a full-rate one.
Router(config-controller)# no channelized 
Router(config-controller)# exit
Router(config)# 
c. Then go into interface configuration mode, where you can use the dsu bandwidth command to create a subrate T3 interface. In this example, a subrate T3 interface is created that has a bandwidth of 16,000 kbps.
Router(config)# interface serial 2/0/1
Router(config-if)# dsu bandwidth 16000 
d. You can now continue to Step 2.

Full T1 Interface

a. Enter controller configuration mode.
Router(config)# controller t3 2/0/2
Router(config-controller)#
b. Use the t1 channel group command to create a T1 interface. In the following example, T1 interface 1 (of 28) is defined as being made up of a single channel group, number 20 (any number between 0 and 23). This channel group consists of all 24 DS0 timeslots.
Router(config-controller)# t1 1 channel-group 20 timeslots 1-24
c. Go to interface configuration mode for the channel group you just created.
Router(config)# interface serial 2/0/2/1:20
d. You can now continue to Step 2.

Fractional T1 Interface

a. Enter controller configuration mode.
Router(config)# controller t3 2/0/3
Router(config-controller)#
b. Use the t1 channel group command to create fractional T1 interfaces. In the following example, T1 interface 3 (of 28) is defined as being made up of three channel groups, numbers 19, 20, and 21. (numbers between 0 and 23 are allowed.) The channel groups consist of a total of 24 DS0 timeslots. Each channel group represents a separate interface.
Router(config-controller) t1 3 channel-group 19 timeslots 1-6, 10
Router(config-controller) t1 3 channel-group 20 timeslots 7,8,9
Router(config-controller) t1 3 channel-group 21 timeslots 11-24
c. Go to interface configuration mode for one of the channel groups. For example:
Router(config)# interface serial 2/0/3/3:19
d. You can now continue to Step 2.

Step 2 Enter the encapsulation method. This example shows the command for using Frame Relay encapsulation. You can also choose PPP or HDLC.
Router(config-if)# encapsulation frame relay
Step 3 If IP routing is enabled on the system, assign an IP address and subnet mask. For example:
Router(config-if)# ip address 172.16.32.49 255.255.0.0
Step 4 Add any configuration subcommands required to enable routing protocols and set the interface line characteristics.

Step 5 Change the shutdown state to up, which enables the interface.
Router(config-if)# no shutdown
Step 6 When you have entered all of the configuration subcommands to complete the configuration, press Ctrl-Z to exit configuration mode.

Step 7 To write the new configuration to NVRAM, type
Router# copy running-config startup-config
After you create an interface configuration, you can modify it at any time by using the appropriate Cisco IOS configuration commands.

Unchannelized T3 Commands

By default, a T3 interface on a 6-Port Channelized T3 line card is channelized into 28 T1 interfaces. You must unchannelize the T3 interface in order to create a full-rate or subrate T3 interface. This section describes the commands you use to create, customize, and test full-rate and subrate T3 interfaces. This section describes the following:

•Entering Controller Configuration Mode for T3

•Configuring a T3 Interface as Unchannelized

•Implementing Subrate T3

•Setting the Framing Type

•Specifying the DSU Mode

•Enabling Scrambling

•Specifying an Idle Character

•Running a BER Test

You can also use the following commands, described in the "Channelized T3 Commands" section, when you are configuring an unchannelized T3: cablelength, clock source, mdl, equipment, and loopback.

Entering Controller Configuration Mode for T3

To create an unchannelized T3 interface, you must first enter controller configuration mode for the T3 controller you want to configure.
controller T3 slot/sub-slot/port
The following example shows how to enter controller configuration mode:
Router(config)# controller T3 1/0/0
Router(config-controller)#
Configuring a T3 Interface as Unchannelized

You can configure the T3 interface as unchannelized (clear channel) by entering the no channelized command.
[no] channelized
channelized
Caution The no channelized command removes all channel groups from a channelized T3 interface. If you have already configured channel groups, use this command with caution.

Use the channelized command to return the interface to its default. The default value for a T3 interface is channelized.

In the following example, an unchannelized T3 interface is created:
Router(config)# controller T3 1/0/0
Router(config-controller)# no channelized
Implementing Subrate T3

You can implement subrate T3 by specifying the bandwidth for an unchannelized T3 interface. To do so, use the command dsu bandwidth bandwidth from interface configuration mode.
dsu bandwidth bandwidth
[no] bandwidth bandwidth
Where bandwidth is a numeric value between 0 and 44210 kbps.

The default bandwidth is 44210 kbps.

To return to the default bandwidth, use the no form of this command.

When you specify a value, the software sets the bandwidth to the closest acceptable bandwidth, based on the timeslot size for the current DSU mode.

In order for you to use this command, the remote side of the connection must have a Cisco 7200 or Cisco 7500 with a PA-T3 or PA-2T3 port adapter or a T3 DSU supported by the dsu mode command.

In the following example, a bandwidth of 16000 kbps is specified:
Router(config)# interface serial 1/0/0
Router(config-if)# dsu bandwidth 16000
Setting the Framing Type

To specify a framing type for the unchannelized T3 controller, use the framing command.
framing [c-bit | m13]
[no] framing [c-bit | m13]
The default framing type is C-bit.

Use the no form of this command to restore the default framing type.

In the following example, framing is set to m13:
Router(config)# interface serial 1/0/0 
Router(config-if)# framing m13
Specifying the DSU Mode

To specify a DSU mode for a selected T3 interface, use the dsu mode command from interface configuration mode. This command configures the line card to emulate a manufacturer's proprietary multiplexing scheme.
dsu mode [Adtran | cisco | Digital-link | Kentrox | Larscom | verilink-highbit | 
verilink-lowbit]
[no] dsu mode 
The default DSU mode is cisco.

Use the no form of the command to return the DSU mode to its default.

In the following example, the DSU mode is set to cisco:
Router(config)# interface serial 1/0/0 
Router(config-if)# dsu mode cisco
Enabling Scrambling

To enable scrambling on an unchannelized T3 interface, use the scramble command from interface configuration mode.
scramble
[no] scramble
The default setting for this command is no scramble (scrambling disabled).

Both sides of the link should have the same scrambling setting.

In the following example, scrambling is enabled on the specified T3 interface:
Router(config)# interface serial 1/0/0
Router(config-if)# scramble
Specifying an Idle Character

To set a specific character on the unchannelized T3 interface to be transmitted between HDLC packets, use the idle character command from interface configuration mode.
idle-character [flags | marks]
[no] idle-character [flags | marks]
Where:

•flags sets an idle character of 0x7e.

•marks sets an idle character of all 0xff.

The default idle character is 0x7e.

Use the no form of the command to return the idle character to its default.

In the following example, the idle character is set to flags:
Router(config)# interface serial 1/0/0 
Router(config-if)# idle-character flags
Note Some systems interpret marks, 0xff, as an abort signal. Therefore, flags, 0x7e, is preferred.

Running a BER Test

You can configure an unchannelized T3 interface to run a bit error rate (BER) test. The test can be used in checking cables and solving signal problems in the field. To send a BER test pattern on an unchannelized T3 interface, use the following interface configuration command:
bert [errors number | pattern pattern] interval time
[no] bert
Where:

•errors number is 1 to 255.

•pattern pattern is

–0s—repetitive test pattern of all zeros (00000º)

–1s—repetitive test pattern of all ones (11111º)

–2^15—pseudorandom O.151 test pattern (32,768 bits long)

–2^20-O153—pseudorandom O.153 test pattern (1,048,575 bits long)

–QRSS-2^20—pseudorandom QRSS O.151 test pattern (1,048,575 bits long)

–2^23—pseudorandom O.151 test pattern (8,388,607 bits long)

•interval time is 1 to 1440 minutes.

You can terminate a BER test at any time using the no bert command.

For more information, refer to the online Cisco 10000 Series Internet Router Troubleshooting Guide.

Examples:

•Send a BER test pseudorandom pattern of 2^20 through T3 interface 1/0/0 for 5 minutes.
Router(config)# interface serial 1/0/0
Router(config-if)# bert pattern 2^20 interval 5
•Send a repetitive pattern of all 1s through T3 interface 1/0/0 for 1440 minutes.
Router(config)# interface serial 1/0/0 
Router(config-if)# bert pattern 1s interval 1440
Channelized T3 Commands

By default, a T3 interface on a 6-Port Channelized T3 line card is channelized into 28 T1 interfaces. This section describes the commands you use to customize and test a channelized T3 interface. This section discusses

•Entering Controller Configuration Mode for T3

•Configuring a T3 Interface as Channelized

•Specifying the Cable Length

•Setting the Framing Type

•Entering MDL Messages

•Specifying the Idle Pattern

•Setting the Clock Source

•Configuring Loopback Mode

•Running Equipment Loopbacks

To use the channels for subscriber traffic, you must configure the T1 and DS0 components. For more information, see the "Channel-Group Command for DS0 Timeslots and T1s" section.

Figure 8-1 shows the levels of configurable interface bandwidth that channelization offers.

Entering Controller Configuration Mode for T3

You may need to enter controller configuration mode for actions involving the T3 interface. For example, enter this mode to change an unchannelized T3 interface back to a channelized one or to set MDL messages.
controller T3 slot/sub-slot/port
The following example shows how to enter controller configuration mode:
Router(config)# controller T3 1/0/0
Router(config-controller)#
Figure 8-1 Channelization of T3s

Configuring a T3 Interface as Channelized

A T3 interface is channelized by default. Use the channelized command if you had previously made the interface unchannelized and want to change the setting.
[no] channelized
channelized
Caution The no channelized command removes all channel groups from a channelized T3 interface. If you have already configured channel groups, use this command with caution.

The following example shows the creation of a channelized T3 interface:
Router(config)# controller T3 1/0/0
Router(config-controller)# channelized
Specifying the Cable Length

To specify the cable length for the T3 controller, use the cablelength command.
cablelength feet
[no] cablelength feet
Where feet is a number from 0 to 450.

The default value is 249 feet.

Use the no form of this command to restore the default cable length.

In the following example, the cablelength value is set to 40 feet.
Router(config)# controller T3 1/0/0
Router(config-controller)# cablelength 40
Note This command causes the system to use one of two settings for impedance matching and pulse shaping, one setting for any cable length between 0 and 249 feet and another setting for any cable length greater than 250 feet. The exact value you enter is stored in the configuration file.

Setting the Framing Type

To specify a framing type for the channelized T3 controller, use the framing command.
framing [c-bit | m23 | auto-detect]
[no] framing [c-bit | m23 | auto-detect]
The default is auto-detect.

Use the no form of the command to return the framing type to its default.

You can instruct the 6-Port Channelized T3 line card to detect the framing type from the far end and transmit that same framing type as follows:
Router(config)# controller T3 1/0/0 
Router(config-controller)# framing auto-detect
Entering MDL Messages

You can configure maintenance data link (MDL) messages (as defined in the ANSI T1.107a-1990 specification) on the channelized T3 interface.

Note MDL messages are supported only when the T3 framing is set for C-bit parity. (See the "Setting the Framing Type" section.)

To configure MDL messages, use the mdl command.
mdl {transmit {path | idle-signal | test-signal} | string {eic | lic | fic | unit | pfi | port 
| generator} id_string}
[no] mdl {transmit {path | idle-signal | test-signal} | string {eic | lic | fic | unit | pfi | 
port | generator} id_string}
Where:

•transmit path enables transmission of the MDL path message.

•transmit idle-signal enables transmission of the MDL idle-signal message.

•eic is the equipment identification code (up to 10 characters).

•lic is the location identification code (up to 11 characters).

•fic is the frame identification code (up to 10 characters).

•unit is the unit identification code (up to 6 characters).

•pfi is the facility identification code to include in the MDL path message
(up to 38 characters).

•port is the equipment port (which initiates the idle signal) to include in the MDL idle signal message (up to 38 characters).

•generator is the generator number to include in the MDL test signal message (up to 38 characters).

The default is that no MDL message is configured.

Use the no form of the command to remove an MDL message.

Examples of configuring MDL messages follow:

•Enable the MDL path message transmission.
Router(config)# controller T3 1/0/0 
Router(config-controller)# mdl transmit path
•Enable the MDL idle signal message transmission.
Router(config-controller)# mdl transmit idle-signal
•Enable the MDL test signal message transmission.
Router(config-controller)# mdl transmit test-signal
•Enter the equipment identification code.
Router(config-controller)# mdl string eic router A
•Enter the location identification code.
Router(config-controller)# mdl string lic test network
•Enter the frame identification code.
Router(config-controller)# mdl string fic building b
•Enter the unit identification code.
Router(config-controller)# mdl string unit abc
•Enter the facility identification code.
Router(config-controller)# mdl string pfi string
•Enter the port number to send in the MDL idle signal message.
Router(config-controller)# mdl string port string
•Enter the generator number to send in the MDL test signal message.
Router(config-controller)# mdl string generator string
Specifying the Idle Pattern

You can set a specific pattern to be transmitted between HDLC packets on all unconfigured timeslots that belong to a channelized T3 interface. To do so, use the idle pattern command.
idle pattern patterns
[no] idle pattern patterns
Where patterns is a number in the range of 0x0 to 0xff (hexadecimal) or 0 to 255 (decimal). You can enter this value in either hexadecimal or decimal form. Values of 0 to 254 set the idle pattern to HDLC flags (0x7e); a value of 255 sets the pattern to 0xff (all ones).

Note Some systems interpret marks, 0xff, as an abort signal. Therefore, flags, 0x7e, is preferred.

The default idle pattern is 0x7e.

Use the no form of the command to return the idle pattern to its default value.

Examples:

•Set a hexadecimal idle pattern.
Router(config)# controller T3 1/0/0
Router(config-controller)# idle pattern 0x10
•Set a decimal idle pattern.
Router(config)# controller T3 1/0/0
Router(config-controller)# idle pattern 23
Setting the Clock Source

At the prompt, set the internal or line clock source for the selected T3 controller using the clock source command. This command is set in controller configuration mode.
clock source {internal | line}
Where:

•internal specifies that the internal clock source is used

•line specifies that the network clock source is used

The default is clock source internal.

In this example, a T3 controller is instructed to use a line clock source.
Router(config)# controller T3 1/0/0
Router(config-controller)# clock source line
Configuring Loopback Mode

You can configure the T3 controller for a loopback mode using the loopback command.
loopback [local | network | remote]
[no] loopback [local | network | remote]
Local and network loopbacks are the same.

To cancel a loopback, use the no form of the command.

For more information on the loopback command, refer to the online Cisco 10000 Series Internet Router Troubleshooting Guide.

Examples:

•Configure the T3 controller for local loopback.
Router(config)# controller T3 1/0/0
Router(config-controller)# loopback local
•Configure the T3 controller for remote loopback.
Router(config)# controller T3 1/0/0
Router(config-controller)# loopback remote
Running Equipment Loopbacks

Use the equipment loopback command to run loopbacks in conjunction with remote equipment.
equipment [customer | network] loopback
[no] equipment [customer | network] loopback
Where:

•customer enables the line card to respond to remote T3 loopback commands from the remote T3 equipment.

•network causes the line card to ignore remote T3 loopback commands.

Use the no form of the command to terminate the loopback.

For more information on the loopback command, refer to the online Cisco 10000 Series Internet Router Troubleshooting Guide.

In the following example, an equipment network loopback is configured:
Router(config)# controller T3 1/0/0
Router(config-controller)# equipment network loopback
Channel-Group Command for DS0 Timeslots and T1s

Each channelized T3 consists of 28 T1s, each of which is divided into 24 timeslots (or DS0s). To create an interface that supports subscriber traffic, you must combine the timeslots into channel groups. Use the t1 channel-group command to create a channel group.

Channel groups have these characteristics:

•A channel group is an interface.

•A channel group can be one timeslot to 24 timeslots in size.

–A channel group that consists of 24 timeslots is a T1 interface.

–A channel group that consists of fewer than 24 timeslots can be described as a fractional T1 interface.

•Each group of 24 timeslots can be divided into multiple fractional T1 interfaces.

•A channel group cannot be part of more than one T1.

Figure 8-1 illustrates channelization possibilities on the 6-Port Channelized T3 line card.

You create a logical channel group using the following command:
t1 t1-number channel-group channel-group-number timeslots list-of-timeslots [speed {56 | 
64}]
[no] t1 t1-number channel-group channel-group-number
Where:

•t1-number is T1 interface number 1 to 28.

•channel-group channel-group-number identifies the channel group with any number from 0 to 23.

•timeslots list-of-timeslots can be 1 to 24 or a combination of subranges within 1 to 24. You can indicate a range using a hyphen, commas, or a combination of both. One timeslot equals one DS0. Refer to the examples below.

•speed {56 | 64} is an optional argument that specifies the speed of a timeslot as either 56 or 64 kbps. The default is 64. (The 56-kbps timeslots are generally used with older T1 equipment that does not support B8ZS and are associated with SF framing.)

Use the no form of the command to remove a logical channel group.

The following examples show how to use the t1 channel-group command:

•In this example, T1 interface 3 includes channel group 20 and consists of nine channelized timeslots:
Router(config)# controller t3 1/0/0 
Router(config-controller)# t1 3 channel-group 20 timeslots 1-8, 10
To enter interface configuration mode for this channel group, enter the following:
Router(config)# interface serial 1/0/0/3:20
•In the following example, T1 interface 4 includes channel group 18 and consists of all 24 timeslots, creating a full T1 interface:
Router(config)# controller t3 1/0/0 
Router(config-controller)# t1 4 channel-group 18 timeslots 1-24
To enter interface configuration mode for this channel group, you enter the following:
Router(config)# interface serial 1/0/0/4:18
•In the following example, T1 interface number 5 is divided into three channel groups, which total 11 timeslots:
Router(config)# controller t3 1/0/0 
Router(config-controller)# t1 5 channel-group 19 timeslots 1-6
Router(config-controller)# t1 5 channel-group 20 timeslots 10
Router(config-controller)# t1 5 channel-group 21 timeslots 7-9, 24
•In the following example, channel group 20 is removed:
Router(config)# controller T3 1/0/0
Router(config-controller)# no t1 1 channel-group 20
Channelized T1 Commands

From controller configuration mode for a T3 interface, you can enter commands to modify aspects of a T1 interface. This section describes the commands for

•Setting the Framing Format

•Controlling Yellow Alarms

•Setting the Clock Source

•Configuring FDL

•Configuring a BER Test

•Configuring Loopback Mode

After you configure a T1 interface, you can add encapsulation, routing, and other instructions by entering interface configuration mode. For example:
Router(config)# interface serial 1/0/0/4:18
Setting the Framing Format

You can specify the T1 interface framing format using the following command:
t1 t1-number framing {esf | sf [hdlc-idle {0x7E | 0xFF}]}
[no] t1 t1-number framing {esf | sf [hdlc-idle {0x7E | 0xFF}]}
Where:

•t1-number is T1 interface number 1 to 28.

•framing is either extended super frame (ESF) or super frame (SF). You can set SF hdlc-idle to 0x7E or 0xFF.

•hdlc-idle options allow you to set the idle pattern for the T1 interface to either 0x7e (the default) or 0xff.

The default framing format is extended super frame (ESF).

Use the no form of the command to return framing to its default value.

Examples:

•Set SF framing format for T1 interface 6.
Router(config)# controller T3 1/0/0 
Router(config-controller)# t1 6 framing sf
•Set ESF framing format for T1 interface 16.
Router(config)# controller T3 1/0/0 
Router(config-controller)# t1 16 framing esf
Controlling Yellow Alarms

Use the t1 yellow command to turn the detection or generation of a yellow alarm on or off.
t1 t1-number yellow {detection | generation}
[no] t1 t1-number yellow {detection | generation}
Where:

•t1-number is T1 interface 1 to 28

•detection means that the interface is told it is failing by the remote device, causing IOS to send a message to the console

•generation means that the interface notifies the remote device if it is failing, causing IOS to send a message to the console

When you select SF framing for a full T1 interface (24 timeslots) that uses the default speed of 64, consider using the no t1-number yellow detection command to turn off yellow alarm detection, because the yellow alarm can be incorrectly detected with SF framing.

In the following example, T1 interface 1 is set to yellow detection:
Router(config)# controller t3 1/0/0
Router(config-controller)# t1 1 yellow detection
Setting the Clock Source

You can set the internal or line (network) clock source for a T1 interface using the controller command.
t1 t1-number clock source {internal | line}
Where:

•t1-number is T1 interface 1 to 28

•internal specifies that the internal clock source is used

•line specifies that the network clock source is used

The default is clock source internal.

In the following example, the interface is instructed to get its clock source from the line:
Router(config)# controller T3 1/0/0
Router(config-controller)# t1 1 clock source line
Configuring FDL

You can enable 1-second transmissions of performance reports through the facility data link (FDL) according to the specification ANSI T1.403, on both ends of the T1 connection. To do so, use the following command:
t1 t1-number fdl ansi
[no] t1 t1-number fdl ansi
Where t1-number is T1 interface 1 to 28.

Use the no form of the command to disable this feature.

Note You can use this command only when the T1 framing is ESF.

In the following example, FDL is enabled:
Router(config)# controller t3 1/0/0
Router(config-controller)# t1 2 fdl ansi
Configuring a BER Test

You can configure an individual T1 interface to run an independent BER test. The test is used to check cables and solve signal problems in the field. To send a BER test pattern on a T1 interface, use the following command:
t1 t1-number bert pattern pattern interval time [unframed]
[no] t1 t1-number bert
Where:

•t1-number is T1 interface number 1 to 28.

•time is 1 to 14,400 minutes.

•pattern is

–0s—repetitive test pattern of all zeros (00000º)

–1s—repetitive test pattern of all ones (11111º)

–2^11—pseudorandom test pattern (2048 bits long)

–2^15—pseudorandom O.151 test pattern (32,768 bits long)

–2^20-O153—pseudorandom O.153 test pattern (1,048,575 bits long)

–2^20-QRSS—pseudorandom QRSS O.151 test pattern (1,048,575 bits long)

–2^23—pseudorandom O.151 test pattern (8,388,607 bits long)

–alt-0-1—repetitive alternating test pattern of zeros (0s) and ones (1s), for example 01010101

•unframed causes the BER test pattern to use the entire T1 bandwidth, including the T1 framing and payload bits. If unframed is omitted, the T1 is either SF or ESF framed as configured by the T1 n framing command, and the BER test pattern occupies only the T1 payload bits.

Note For each T3, you can run only one BER test at a time.

You can terminate a BER test at any time using the no form of the command.

For more information, refer to the online Cisco 10000 Series Internet Router Troubleshooting Guide.

Examples:

•Send a BER test pseudorandom pattern of 2^20 through T1 interface 10 for 5 minutes.
Router(config)# controller T3 1/0/0 
Router(config-controller)# t1 10 bert pattern 2^20 interval 5 unframed
•Send a repetitive pattern of all 1s through T1 interface 10 for 14,400 minutes (240 hours).
Router(config)# controller T3 1/0/0
Router(config-controller)# t1 10 bert pattern 1s interval 14400 unframed
Configuring Loopback Mode

If problems occur when you configure a T1 interface, you can troubleshoot the line card by using the following command from controller configuration mode:
t1 t1-number loopback [local | network {line | payload} | remote [line [fdl {ansi | 
bellcore} | inband] | payload [fdl | ansi]]]
[no] t1 t1-number loopback
Where:

•t1-number is T1 interface 1 to 28.

•local loops the router output data back toward the router at the T1 framer and sends an alarm indication signal (AIS) out toward the network.

•network {line | payload} loops the data back toward the network and automatically sets a local loopback at the HDLC controllers (line) or loops the payload data back toward the network and automatically sets a local loopback at the HDLC controller (payload).

•remote line fdl {ansi | bellcore} sends a repeating, 16-bit ESF data link keyword to the remote end, requesting that it enter into a network line loopback. You can specify an ANSI or Bellcore keyword.

Note Loopback codes are defined in ANSI T1.404-1989 Table 3 (Assigned Bit-Oriented ESF Data-Link Messages)

The 6-Port Channelized T3 line card sends the following code for remote line fdl ANSI loopback:

–Line Loopback Active Code: 0 000111 01111111

–Line Loopback Deactivate Code: 0 010010 01111111

The 6-Port Channelized T3 line card sends the following code for remote line FDL Bellcore (SmartJack) loopback:

–Network Use (loopback active) Code: 0 001001 01111111

–Network Use (loopback deactivate) Code: 0 010010 01111111

•remote line inband sends a repeating inband pattern to the remote end, requesting entry into a network line loopback. The inband loopback request overwrites all data in the T1 with the loop request pattern. The remote end responds to this code only after it receives the pattern continuously for at least five seconds.

–Repeating Inband Loopback Activate Code: 00001

–Repeating Inband Loopback Deactivate Code: 001

•remote payload [fdl] [ansi] sends a repeating, 16-bit ESF data link code word to the remote end, requesting entry into a network payload loopback. Using fdl and ansi enables the remote payload facility data link (FDL) ANSI bit loopback on the T1 channel.

Note Loopback codes are defined in ANSI T1.404-1989 Table 3 (Assigned Bit-Oriented ESF Data-Link Messages)

The 6-Port Channelized T3 line card sends the following code for remote payload fdl ANSI loopback:

–Payload Loopback Active Code: 0 001010 011111111

–Payload Loopback Deactivate Code: 0 011001 011111111

Use the no form of the command to terminate a loopback.

For more information on this command, refer to the online Cisco 10000 Series Internet Router Troubleshooting Guide.

Examples:

•Configure the T3 controller for local loopback on T1 interface 1.
Router(config)# controller t3 1/0/0
Router(config-controller)# t1 1 loopback local
•Configure the T3 controller for remote FDL ANSI loopback on T1 interface 1.
Router(config)# controller t3 1/0/0
Router(config-controller)# t1 1 loopback remote line fdl ansi