E1 PRI for the Cisco AS5200

Description

The Cisco AS5200 Universal Access Server supports E1 PRI configuration. Channelized E1 PRI offers 30 B channels and 1 D channel on each controller. Because there are two E1 controllers in the dual E1 PRI card for the Cisco AS5200, 60 B channels are available. Unlike most controller E1 configurations in the Cisco product family, the Cisco AS5200 requires a clock source to be specified on each controller, which is set with the clock source command.

Benefits

Configuring channelized E1 PRI on a Cisco AS5200 enables up to 60 remote connections to network resources at any given time.

List of Terms

The following terms are defined for understanding E1 PRI configuration on the Cisco AS5200.

Channelized E1--An access link operating at 2.048 Mbps that is subdivided into 30 B channels and 1 D channel. Channelized E1 supports DDR, Frame Relay, and X.25.

E1 controller--A hardware device that is configured to provide interfaces.

Prerequisites

To use this feature, you must select a service provider switch type that accommodates ISDN PRI. The switch type you choose must match the switch type offered by your telco provider. The dual E1 ISDN PRI card must be installed in the Cisco AS5200 before you attempt to configure channelized E1.

Configuration Tasks

ISDN Primary Rate Interface (PRI) is supported on the Cisco AS5200. Channelized E1 ISDN PRI offers 30 B channels and 1 D channel.

Channelized E1 is supported by corresponding controllers. An E1 controller has one physical network termination. However, it can have many virtual interfaces, depending on the configuration.

To configure ISDN PRI on a channelized E1 controller, perform the following tasks, beginning in global configuration mode:

Task	Command
Step 1 Select a service provider switch type that accommodates PRI.	isdn switch-type switch-type
Step 2 Define the controller location in the Cisco AS5200 by unit number, ranging from 1 to 2.	controller e1 number
Step 3 Define the framing characteristics as cyclic redundancy check 4 (CRC4).	framing crc4
Step 4 Define the line code as high-density bipolar 3 (HDB3).	linecode hdb3
Step 5 Specify one E1 line to serve as the primary or most stable clock source line.	clock source line primary1
Step 6 Configure ISDN PRI.	pri-group [timeslots range]

If you do not specify the time slots, the specified controller is configured for 30 B channels and one D channel.

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Note Any router configured for ISDN support must be connected to the same switch type on all its ISDN interfaces.

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Configuration Example

The following example configures the Cisco AS5200 to use the E1 controller 0 as the primary clocking source and the E1 controller 1 as the secondary clocking source:

AS5200(config)# controller e1 0
AS5200(config-controller)# clock source line primary
AS5200(config-controller)# exit
AS5200(config)# controller e1 1
AS5200(config-controller)# clock source line secondary

Command Reference

This section provides command reference documentation for the clock source command, which is a new command used for configuring E1 PRI on a Cisco AS5200.

All other command used with this feature are documented in the Cisco IOS Release 11.2 Configuration Fundamentals Command Reference.

clock source (controller)

Use the clock source controller configuration command to set the E1 line clock source for the Cisco AS5200.

clock source {line {primary | secondary} | internal}
no clock source {line {primary | secondary} | internal}

Syntax Description

line	Specifies the E1 line from which the clocking is taken.
internal	Specifies internal clocking.
primary	Primary TDM clock source.
secondary	Secondary TDM clock source.

Default

Primary TDM clock source is taken from the E1 controller 0 on the Cisco AS5200.

Secondary TDM clock source is taken from the E1 controller 1 on the Cisco AS5200.

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Configure the clock source line primary command on the controller that takes the most reliable clocking from an E1 line. Configure the clock source line secondary command on the controller that has the next best known clocking. With this configuration, the primary line clocking is backed up to the secondary line if the primary clocking shuts down.

Examples

The following example configures the Cisco AS5200 to use the E1 controller 0 as the primary clocking source and the E1 controller 1 as the secondary clocking source:

AS5200(config)# controller e1 0
AS5200(config-controller)# clock source line primary
AS5200(config-controller)# exit
AS5200(config)# controller e1 1
AS5200(config-controller)# clock source line secondary

Related Commands

framing
linecode

What to Do Next

Refer to the Cisco AS5200 Dual E1 PRI Card Configuration Note for additional descriptions of E1 PRI software configuration.