call manager 4.2 and 6.1

Unanswered Question
Aug 5th, 2008

Hi all,

I have the following set,

I have a call manager 6.1 and a call manager 4.2 both are connected to a normal switch... i have 4 cisci ip phones of which 2 are configured and registered with ccm 4.2 and the other two are registered with CCM 6.1... i can make calls between the two phones tat are registered with the same call manager but i cant make calls from a phone registered with call manager 4.2 to the phones connected to CCM 6.1. i dont know how i can set this up... i am not working on a huge network i am doing this in a test Lab.

I have this problem too.
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Brandon Buffin Tue, 08/05/2008 - 04:51

There are several ways to do this. The simplest is to create an Intercluster Trunk on each CCM. Go to Device > Trunk on each CCM and create a Non-Gatekeeper Controlled Intercluster Trunk that points to the other cluster. Make sure that the trunks have a calling search space that can access the partitions assigned to your phones.

Hope this helps. If so, please rate the post.


rob.huffman Tue, 08/05/2008 - 05:02

Hi Mohammed,

To call between the two CCM Clusters you will require an ICT (Intercluster Trunk)

Intercluster Trunk (Non-Gatekeeper Controlled)

In a distributed network that has no gatekeeper control, you must configure a separate intercluster trunk for each device pool in a remote cluster that the local Cisco Unified CallManager can call over the IP WAN. The intercluster trunks statically specify the IP addresses or host names of the remote devices.To choose this method, use Device > Trunk and choose Inter-Cluster Trunk (Non-Gatekeeper Controlled) in Cisco Unified CallManager Administration.


Note You must specify the IP addresses of all remote Cisco Unified CallManager nodes that belong to the device pool of the remote non-gatekeeper-controlled intercluster trunk.


You also configure the necessary route patterns and route groups to route calls to and from the intercluster trunks.

Trunk Configuration Settings

Non-Gatekeeper Controlled Trunks

If no gatekeeper is used, then the only choice for cluster-to-cluster trunking is an intercluster trunk (non-gatekeeper controlled).

This trunk type is the simplest and is used for connecting to other Cisco Unified CallManager clusters in either a multi-cluster single campus or a distributed call processing deployment. This trunk does not use a gatekeeper for call admission control, although it may use locations configured in Cisco Unified CallManager if bandwidth control is required. This type of trunk must be used only for communication with other Cisco Unified CallManager clusters because it utilizes the Intercluster Trunk Protocol.

When defining this type of trunk, you may define up to three remote Cisco Unified CallManager servers in the same destination cluster. The trunk will automatically load-balance across all defined servers. In the remote cluster, it is important to configure a corresponding intercluster trunk (non-gatekeeper controlled) that has a Cisco Unified CallManager group containing the same servers that were defined as remote Cisco Unified CallManager servers in the first cluster. A similar configuration is required in each Cisco Unified CallManager cluster connected by the intercluster trunks.

For example, if Cluster 1 has a trunk to Cluster 2, and Cluster 2 has a trunk to Cluster 1, the following configurations would be needed:

•Cluster 1

-Servers B, C, and D are configured as members of the Cisco Unified CallManager group defined in the device pool associated with the trunk to Cluster 2.

-The non-gatekeeper controlled trunk has Cluster 2's remote servers D, E, and F configured.

•Cluster 2

-Severs D, E, and F are configured as members of the Cisco Unified CallManager group defined in the device pool associated with the trunk to Cluster 1.

-The non-gatekeeper controlled trunk has Cluster 1's remote servers B, C, and D configured.

Hope this helps!


EDIT: Brandon, you are too fast for my super horrendous typing skills ;-)

mohammedanasshaikh Tue, 08/05/2008 - 05:17

Thanks a lot Rob and brandon i will go through the document and post if i have any questions here again... thanks again for the help


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