Channelized E1 Signaling for the Cisco AS5200

Description

The Cisco AS5200 Universal Access Server now supports channel associated signaling for channelized E1 lines, which are commonly deployed in networks in Latin America, Asia, and Europe. Once this feature is configured on a single E1 controller, up to 30 remote users can simultaneously dialin to the Cisco AS5200 through networks running the R2 protocol.

Typically all 30 channels of a channelized E1 line are used for analog calls. However, the Cisco AS5200 requires a signal converter to perform conversions between R2 signaling and ear and mouth signaling (also known as E&M). Currently the Cisco AS5200 supports E&M signaling on its E1 controllers. It does not support R2 signaling. Because the Cisco AS5200 has two physical E1 ports on its dual E1 PRI board, up to 60 simultaneous connections can be made through one dual E1 PRI board. See Figure 5.

Figure 5: Remote PC Accessing Network Resources Through the Cisco AS5200

Note For information on how to configure an Anadigicom converter, refer to the documentation that came with the Anadigicom converter.

List of Terms

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 in the Cisco AS5200 that is configured to provide interfaces.

R2 signaling--An international signaling standard that is used for making analog connections. Because this signaling is not supported in the Cisco AS5200, an E1-to-E1 converter device is required.

Channel associated signaling--Call signaling, such as on-hook and off-hook, that is configured on an E1 controller. The actual signaling exists in the16th channel (also know as timeslot). This signaling enables the access server to send or receive analog calls. Robbed bit signaling is used for a similar purpose, but it is configured on a T1 controller.

Timeslots--Available data slots that comprise a channelized E1 line, which can be used to transmit analog calls. A channelized E1 has 30 timeslots; however, the 16th timeslot is reserved for the R2 signaling protocol. Each timeslot can forward one analog call.

Prerequisites

The dual E1 PRI card must be installed in the Cisco AS5200 before you attempt to configure this feature.

Configuration Tasks

Channel associated signaling is configured to support channel banks in the network that convert various battery and ground operations on analog lines into signaling bits, which are forwarded over digital lines. This signaling is configured with the cas-group controller configuration command on on each of the Cisco AS5200's E1 controllers. Each E1 controller has one physical network termination.

To configure the Cisco AS5200's controllers, perform the following tasks, beginning in global configuration mode:

Task	Command
Step 1 Define the controller location in the Cisco AS5200 by unit number, ranging from 1 to 2.	controller e1 number
Step 2 Configure channel associated signaling and the R2 signaling protocol on a specified number of timeslots.	cas-group channel-number timeslots range type signal-type
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

¹ Specify the other E1 line as the secondary clock source with the clock source line secondary command.

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

Configuration Examples

This section provides channelized E1 sample configurations for the Cisco AS5200. You can configure the 30 available channels with channel associated signaling, channel grouping, or a combination of the two.

Allocating All Channels for Channel Associated Signaling

The following example configures channels (also known as timeslots) 1-30 with ear and mouth channel signaling and feature group b support on a Cisco AS5200. The actual signaling transmitted in the 16th timeslot; therefore, the timeslot is not brought up or displayed in the output.

Router#
%SYS-5-CONFIG_I: Configured from console by console
Router# configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)# controller e1 0
Router(config-controller)# cas-group 1 timeslots 1-31 type e&m-fgb
Router(config-controller)#
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 1 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 2 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 3 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 4 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 5 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 6 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 7 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 8 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 9 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 10 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 11 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 12 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 13 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 14 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 15 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 17 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 18 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 19 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 20 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 21 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 22 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 23 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 24 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 25 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 26 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 27 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 28 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 29 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 30 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 31 is up

Allocating All Channels to Serve as One Channel Group

The following example shows you how to configure all timeslots as one channel group on a Cisco AS5200:

AS5200(config)# controller e1 0
AS5200(config-controller)# channel-group 1 timeslots 1-31
AS5200(config-controller)#
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1:1, changed state to down
%LINK-3-UPDOWN: Interface Serial1:1, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial1:1, changed state to up

Mixing and Matching Channels

The following example shows you how to configure an E1 controller to support a combination of channel associated signaling and channel grouping. The range of timeslots that you allocate must match the timeslot allocations that your central office chooses to use. This is a rare configuration because of the complexity of aligning the correct range of timeslots on both ends of the connection.

Timeslots 1 through 15 are assigned to channel group 1. In turn, these timeslots are assigned to serial interface 0 and virtual channel group 1 (shown as serial 0:1).

AS5200(config)# controller e1 0
Router(config-controller)# channel-group 1 timeslots 1-15
Router(config-controller)#
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0:1, changed state to
down
%LINK-3-UPDOWN: Interface Serial0:1, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0:1, changed state to up

Timeslots 17 to 31 are configured with channel associated signaling.

Router(config-controller)# cas-group 2 timeslots 17-31 type e&m-fgb
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0:1, changed state to
down
Router(config-controller)#
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 17 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 18 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 19 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 20 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 21 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 22 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 23 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 24 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 25 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 26 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 27 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 28 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 29 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 30 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 31 is up
Router(config-controller)#

Command Reference

This section provides command reference documentation for the cas-group controller configuration command, which has been modified to support channel associated signaling for E1 lines.

Additional commands used with this feature are documented in the Cisco IOS Release 11.2 Configuration Fundamentals Command Reference.

cas-group

To configure an E1 controller on a Cisco AS5200 with channel associated signaling, use the cas-group controller configuration command. Use the no form of this command to disable channel associated signaling for one or more timeslots.

cas-group channel-number timeslots range type signal-type
no cas-group channel-number timeslots range type signal-type

Syntax Description

channel-number

Specifies a single channel group number, which can be between 0 and 30.

timeslots range

(Optional) Specifies a timeslot range of values from 1 to 31. You can specify timeslot ranges (for example, 1-31), individual timeslots separated by commas (for example 1, 3, 5), or a combination of the two (for example 1-3, 8, 17-31). The 16th time slot is not specified in the command line, because it is reserved for transmitting the channel signaling.

type signal-type

Specifies the type of channel associated signaling. Choose one of the following signal types to configure:

· e&m-fgb--Specifies ear and mouth channel signaling with feature group b support.

· e&m-fgd--Specifies ear and mouth channel signaling with feature group d support.

· fxs-loopstart-- Specifies foreign exchange system loopstart signaling support.

· fxs-groundstart--Specifies foreign exchange system ground start signaling support.

· sas-loopstart--Specifies specific access station loopstart signaling support.

· sas-groundstart--Specifies specific access station ground start signaling support.

Default

No channel associated signaling is configured on the controller.

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to configure support for incoming and outgoing call signals (such as on-hook and off-hook) on each E1 controller.

If you specify the timeslot range 1-31 at the router prompt, the system software automatically uses the 16th timeslot to transmit the channel associated signaling.

Example

The following example configures timeslots 1-30 with ear and mouth channel signaling with feature group b support on a Cisco AS5200. Because the signaling is transmitted through the 16th timeslot, this timeslot is not brought up or displayed in the output.

Router#
%SYS-5-CONFIG_I: Configured from console by console
Router# configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)# controller e1 0
Router(config-controller)# cas-group 1 timeslots 1-31 type e&m-fgb
Router(config-controller)#
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 1 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 2 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 3 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 4 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 5 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 6 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 7 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 8 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 9 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 10 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 11 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 12 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 13 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 14 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 15 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 17 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 18 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 19 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 20 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 21 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 22 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 23 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 24 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 25 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 26 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 27 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 28 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 29 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 30 is up
%DSX0-5-RBSLINEUP: RBS of controller 0 timeslot 31 is up

What to Do Next

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

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