Cisco Unified Communications Manager (CallManager)

Configuring External CFA Extension on IP Phone When Doing Overlap Sending

Document ID: 24340

Updated: Feb 03, 2006



This document explains how to configure an external (PSTN/PBX) call forward all (CFA) extension on the IP phone when performing overlap sending.



There are no specific requirements for this document.

Components Used

The information in this document is based on these software and hardware versions:

  • Cisco CallManager versions 3.1, 3.2, and 3.3


For more information on document conventions, refer to the Cisco Technical Tips Conventions.

Configure External CFA Extension on IP Phone

When your system is configured for overlap sending, you usually have a route pattern configured with a digit followed by a period, such as "9.". With this route pattern, if you want to configure an external CFA extension on the IP phone, the Cisco CallManager only accepts the 9 and no additional digits. To overcome this, you need to configure an additional route pattern with a wildcard character, such as "9.!" and put this in a separate partition. Create a calling search space (CSS). Put this partition as the highest priority in this CSS. On the IP phone Directory Number configuration, put this CSS in the Forward All field.

To configure the CFA extension, perform these steps.

  1. Open the Cisco CallManager Administration window.

  2. Create a partition.

    1. From the menu bar, select Route Plan > Partition.

    2. Click Add a New Partition.

    3. Enter a name in the Partition Name field. In this example, overlap is used.

    4. Enter a description in the Description field.

    5. Click Insert to add the new partition.

  3. Create a CSS. Select the created partition as the highest priority.

    In this example, overlap-css is used.

    1. From the menu bar, select Route Plan > Calling Search Space.

      The Calling Search Space Configuration window appears.


    2. Click the Add a New Calling Search Space link.

    3. Enter the appropriate information in the Description and Available Partitions fields.

    4. In the Selected Partitions field, select your newly-created partition (in this case, overlap).

      Use the up and down arrows to the right of the field to select the newly-created partition.

    5. Click Insert.

  4. Create an additional route pattern.

    This should be similar to your existing route pattern along with the wildcard character (!). For example, if the existing route pattern is "9.", the new route pattern is "9.!".

    1. From the menu bar, select Route Plan > Route Pattern.

      The Route Pattern Configuration window appears.


    2. Click Add a New Route Pattern.

    3. In the Route Pattern field, type the route pattern digit along with the wildcard character.

    4. In the Partition field, assign the created partition (in this case, overlap) to this route pattern.

    5. Enter the remaining appropriate settings. Click Insert.

  5. Go to the Directory Number configuration of the IP phone. Assign the created CSS to Forward All.


Verify the Configuration

This section provides the information to confirm that your configuration works properly.

On the IP phone, click CFWdAll. Enter the external CFA extension.

Note: Since you are using a route pattern such as "9.!", you need to wait until the T302 timer expires before the Cisco CallManager accepts the CFA extension. By default, this timer is ten seconds. If this delay is too long, change the T302 service parameter to a shorter length of time, for example, five seconds.

For more information on changing service parameters, refer to Service Parameters Configuration.


There is currently no specific troubleshooting information available for this configuration.

Related Information

Updated: Feb 03, 2006
Document ID: 24340