Configuring the Channelized OC-12 Line Card

This chapter describes the procedures for configuring a Cisco 10000 ESR channelized OC-12 (ChOC-12) line card (Figure 6-1). The chapter includes a table of default values and a detailed interface configuration example. This information is followed by sections that describe the principal commands:

Figure 6-1: ChOC-12 Line Card

ChOC-12 Line Card Default Values

Table 6-1 lists default configuration values for the ChOC-12 line card and indicates which values apply to which line speeds. The commands marked with an asterisk (*) are described in the Cisco IOS Command Reference. The other commands are among those described in this chapter.

The table 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 6-1: ChOC-12 Line Card Default Values

Command Name Default Setting Command Syntax Remote Side Setting DS0 T1 Ch T3 Unch T3

Controller Configuration Mode

channelized

channelized

[no] channelized
—

x

x

clock source¹

internal

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

x

x

T1 clock source

internal

t1 ch_group_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

44210

dsu bandwidth bandwidth
Same

x

DSU mode

cisco

dsu mode mode
Same

x

encapsulation*

HDLC

encapsulation [hdlc | ppp]
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

¹The default value for SONET clock source is line. At least one side of the connection must be set to internal.

Command Name	Default Setting	Command Syntax	Remote Side Setting	DS0	T1	Ch T3	Unch T3
Controller Configuration Mode
channelized	channelized	[no] channelized	—			x	x
clock source¹	internal	clock source [line \| internal]	At least one side set to internal			x	x
T1 clock source	internal	t1 ch_group_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	44210	dsu bandwidth bandwidth	Same				x
DSU mode	cisco	dsu mode mode	Same				x
encapsulation*	HDLC	encapsulation [hdlc \| ppp]	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

ChOC-12 Line Card Syntax

To specify an interface number in a configuration command, use the syntax in Table 6-2 to identify interfaces on the ChOC-12 line card.

Table 6-2: ChOC-12 Interface Syntax
Type of Interface
Slot
Subslot
Port
STS-1 Path (T3)
T1 Number
Channel Group Number

Unchannelized

1 to 8/

0/

0.

1 to 12

—

—

Channelized

1 to 8/

0/

0.

1 to 12/

1 to 28:

0 to 23

**Table 6-2: ChOC-12 Interface Syntax**
Type of Interface	Slot	Subslot	Port	STS-1 Path (T3)	T1 Number	Channel Group Number
Unchannelized	1 to 8/	0/	0.	1 to 12	—	—
Channelized	1 to 8/	0/	0.	1 to 12/	1 to 28:	0 to 23

Examples:

Modifying T1 interface 6 in controller configuration mode:

Router(config)# controller t3 2/0/0.1
Router(config-controller)# t1 6 command

Modifying T1 interface 6, channel group number 8 in interface configuration mode:

Router(config)# interface serial 2/0/0.1/6:8
Router(config-if)

ChOC-12 Line Card Interface Configuration Sample

You can configure up to 12 STS-1 connections on a ChOC-12 line card. Each STS-1 connection can be configured as a T3 interface. 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 Enter SONET controller-configuration mode, where you set up T3 interfaces. In this example, the ChOC-12 line card is in slot 2.

Router(config)# controller sonet 2/0/0

Router(config-controller)#

Step 2 Assign an STS-1 path to a T3 interface. In this example, the path command is used to set up four T3 interfaces:

Router(config-controller)# path 1 controller t3

Router(config-controller)# path 2 controller t3

Router(config-controller)# path 3 controller t3

Router(config-controller)# path 4 controller t3

Router(config-controller)# exit

The path command is used primarily when you first set up the ChOC-12 card.

Step 3 Create an interface. In the following examples, each type of interface is created in a different T3 controller (4/0/0.1 through 4/0/0.4).

Full-Rate T3 Interface

a. Enter controller configuration mode.

Router(config)# controller t3 2/0/0.1
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 2/0/0.1

d. You can now continue to Step 2.

Subrate T3 Interface

a. Enter controller configuration mode.

Router(config)# controller t3 2/0/0.2
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. Enter 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 16000 kbps.

Router(config)# interface serial 2/0/0.2
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 2/0/0.3
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 2/0/0.3/1:20

d. You can now continue to Step 2.

Fractional T1 Interface

a. Enter controller configuration mode.

Router(config)# controller t3 2/0/0.4
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 (any numbers between 0 and 23). 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 2/0/0.4/3:19

d. You can now continue to Step 2.

Step 4 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 5 If IP routing is enabled on the system, you can assign an IP address and subnet mask. For example:

Router(config-if)# ip address 172.16.32.49 255.255.0.0

Step 6 Add any configuration subcommands required to enable routing protocols and set the interface line characteristics.

Step 7 Change the shutdown state to up, which enables the interface.

Router(config-if)# no shutdown

Step 8 When you have entered all of the configuration subcommands to complete the configuration, press Ctrl-Z to exit configuration mode.

Step 9 Write the new configuration to NVRAM.

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.

SONET Commands

By default, the ChOC-12 line card consists of 12 STS-1 connections. To set up the ChOC-12 line card, you must configure each STS-1 as a T3 interface. This section describes the commands used to create T3 interfaces and test STS-1 connections. This section describes the following:

Entering Controller-Configuration Mode for SONET

You must enter the following command to enter controller-configuration mode, where you can configure the SONET controller:

controller sonet slot/subslot/port

Where slot is 1 to 8, and subslot and port are both 0.

The following example shows you how to enter SONET controller configuration mode for a card in slot 2:

Router(config)# controller sonet 2/0/0

ROuter(config-controller)#

Designating an STS-1 Path as a T3 Interface

Use the path command to designate an STS-1 path as a T3 interface. You can designate up to 12 STS-1 channels. (Figure 6-2 shows the relationship between the OC-12 pipe, T3 interfaces, and T1 interfaces.)

path STS_number controller t3

[no] path STS_number controller t3

Where STS_number is the virtual T3 channel. Enter a value from 1 to 12.

Use the no form of the command to remove a T3 interface.

In this example, STS-1 number 1 is defined as a T3 line and a serial or controller T3 interface number 2/0/0.1 is generated:

Router(config)# controller sonet 2/0/0

Router(config-controller)# path 1 controller t3

Figure 6-2: Each T3 Interface Can Be Channelized into 28 T1 Lines

Setting the Clock Source

At the prompt, set the internal or line clock source for the SONET controller using the clock source command.

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 line.

If you set the clock source on one side of the connection to line, you must set the clock source on the other side to internal.

In this example, the SONET controller is instructed to use an internal clock source:

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

Router(config-controller)# clock source internal

Configuring Loopback Mode

You can enable SONET controller loopbacks by using the loopback command.

loopback [internal | line]
[no] loopback [internal | line]

The default is no loopback.

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

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

The commands in this example run an internal loopback on the ChOC-12 line card in slot 2:

Router(config)# controller sonet 2/0/0

Router(config-controller)# loopback internal

Unchannelized T3 Commands

By default, a T3 interface on a ChOC-12 line card is channelized into 28 T1 interfaces. You must unchannelize the T3 interface 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:

You can also use the following commands, described in the "Channelized T3 Commands" section, when configuring unchannelized T3: 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.path

Where path specifies the T3 interface number.

The following example shows how to enter controller configuration mode:

Router(config)# controller T3 1/0/0.1

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

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 1/0/0.1

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 dsu bandwidth bandwidth command 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 16,000 kbps is specified:

Router(config)# interface serial 1/0/0.1

Router(config-if)# dsu bandwidth 16000

Tips "Configuring Multilink Point-to-Point Connections," describes an alternative way to reduce the bandwidth of a T3 channel.

Setting a 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 1/0/0.1

Router(config-if)# framing m13

Specifying a 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 1/0/0.1

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).

Ensure that both sides of the link have the same scrambling setting.

In the following example, scrambling is enabled on the specified T3 interface:

Router(config)# interface serial 1/0/0.1

Router(config-if)# scramble

Specifying the 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 1/0/0.1

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 is used to check cables and solve 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 (00000...)
- 1s—repetitive test pattern of all ones (11111...)
- 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 ESR Troubleshooting Guide.

Examples:

Send a BER test pseudorandom pattern of 2^20 through T3 line 1 for 5 minutes.

Router(config)# interface serial 1/0/0.1
Router(config-if)# bert pattern 2^20 interval 5

Send a repetitive pattern of all 1s through T3 line 1 for 1440 minutes.

Router(config)# interface serial 1/0/0.1
Router(config-if)# bert pattern 1s interval 1440

Channelized T3 Commands

By default, a T3 interface on a ChOC-12 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 describes procedures for

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

Figure 6-3 illustrates the levels of configurable interface bandwidth that channelization offers.

Entering Controller Configuration Mode for T3

You may need to enter controller configuration mode for 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.path

Path specifies the T3 interface number.

The following example shows how to enter controller configuration mode:

Router(config)# controller T3 1/0/0.1

Router(config-controller)#

Figure 6-3: 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.

[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 1/0/0.1

Router(config-controller)# channelized

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 ChOC-12 line card to detect the framing type from the far end and transmit that same framing type:

Router(config)# controller T3 1/0/0.1

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 1/0/0.1
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 timeslot interfaces 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 1/0/0.1
Router(config-controller)# idle pattern 0x10

Set a decimal idle pattern.

Router(config)# controller T3 1/0/0.1
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 1/0/0.1

Router(config-controller)# clock source line

Configuring Loopback Mode

You can configure the T3 controller for 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 ESR Troubleshooting Guide.

Examples:

Configure the T3 controller for local loopback.

Router(config)# controller T3 1/0/0.1
Router(config-controller)# loopback local

Configure the T3 controller for remote loopback.

Router(config)# controller T3 1/0/0.1
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 ESR Troubleshooting Guide.

The following example shows configuration of an equipment network loopback:

Router(config)# controller T3 1/0/0.1

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 1 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 6-3 illustrates channelization possibilities on the ChOC-12 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 the 1 to 24 interval. You can indicate a range using a hyphen, commas, or a combination of both. One timeslot equals one DS0. (See 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 1/0/0.1
Router(config-controller)# t1 3 channel-group 20 timeslots 1-8, 10

: To enter interface configuration mode for T1 interface 3 channel group 20, enter the following:

Router(config)# interface serial 1/0/0.1/3:20

In this example, t1 interface 4 includes channel group 18 and consists of all 24 timeslots, creating a full T1 interface:

Router(config)# controller t3 1/0/0.1
Router(config-controller)# t1 4 channel-group 18 timeslots 1-24

: To enter interface configuration mode for T1 interface 4 channel group 18, enter the following:

Router(config)# interface serial 1/0/0.1/4:18

In the following example, T1 interface number 5 is divided into three channel groups, which total 11 timeslots:

Router(config)# controller t3 1/0/0.1
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 1/0/0.1
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

After you configure T1 interface, you can add encapsulation, routing, and other instructions by entering interface configuration mode. For example:

Router(config)# interface serial 1/0/0.1/4:18

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 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 1/0/0.1
Router(config-controller)# t1 6 framing sf

Set ESF framing format for T1 interface 16:

Router(config)# controller T3 1/0/0.1
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 2/0/0.1

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 1/0/0.1

Router(config-controller)# t1 1 clock source line

Configuring FDL

You can enable 1-second transmissions of performance reports through the f acility data link (FDL) according to the specification ANSI T1.403, on both ends of theT1 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 1/0/0.1

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

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)

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 ESR Troubleshooting Guide.

Example:

Send a BER test pseudorandom pattern of 2^15 through T1 interface 10 for 5 minutes.

Router(config)# controller T3 1/0/0.1
Router(config-controller)# t1 10 bert pattern 2^15 interval 5 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 [local | network {line | payload} | remote 
[line [fdl {ansi | bellcore} | inband] | payload [fdl | ansi]]]

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 controllers (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.
remote line inband sends a repeating, 5-bit inband pattern to the remote end, requesting entry into a network line loopback.
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.

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

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

Examples:

Configure the T3 controller for local loopback on T1 interface 1.

Router(config)# controller t3 1/0/0.1
Router(config-controller)# t1 1 loopback local

Configure the T3 controller for remote FDL ANSI loopback on T1 interface 1.

Router(config)# controller t3 1/0/0.1
Router(config-controller)# t1 1 loop remote line fdl ansi

Table of Contents

Configuring the Channelized OC-12 Line Card

Setting the Clock Source