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One Untiy intergrate with two CCM Clusters????

We have CCM4.1 cluster now and Unity VM only. We are going to install another CCM cluster.

Is it possible have one unity VM intergrate with two CCM Clusters??

If yes, do I need extra liscene or something else?




Re: One Untiy intergrate with two CCM Clusters????

Actually, I just found something.

Setup Requirements

The following components are necessary to integrate Cisco Unity with multiple Cisco CallManager clusters:

Cisco CallManager servers (version 3.0) configured as a cluster at each location

A network connection between the clusters

An H.323 voice gateway for each cluster to connect to the IP WAN or PSTN

An H.323 gatekeeper to provide call admission control

Cisco Unity 3.0 or later, set up and integrated with the clusters


Under setup requirements: need H.323 voice gateway for PSTN?? Can I use MGCP??

The cisco doc mention it:

A subscriber homed on the Cisco Unity server at location A cannot log on to a another Cisco Unity server at location B. If the subscriber is temporarily at location B and wants to receive voice messages, the subscriber must dial the pilot number of the Cisco Unity server at location A to log on.

I understand the above part, but can we transfer voice mail between Location A and Location B??




Re: One Untiy intergrate with two CCM Clusters????


What version of Unity?

We have 4 Call Manager clusters working with a single Unity server (w/failover). Perform the CCM voice mail set up ,and run the Unity Integration Manager utility to add the additional cluster. You will have to set up Unity ports for each cluster. That may mean you need to license extra ports if you don't have enough to handle both. Other than that you just need enough total subscriber licenses. Hopefully your dial plan is not overlapping between the 2 clusters, as that will complicate the setup.

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Re: One Untiy intergrate with two CCM Clusters????

Hi all,

Thanks for all the reply first.

I have couple questions to follow up if you do not mind.

1. We have existing one unity VM 4.04 now. So we are going to have two new Unity Server for primary and secondary (failover). I believe that we need external server for message store? In other word, I need another server for message store. AM I right?

We are Not going to have Unified Messaging.

2. If Unity has been installed at Location A and B. I know I have to do digital networking between two UNITY server for transfer voice mail, also for login from another location A if user at location B.

Do I need to do same thing in my situation?? I doubt it.

3. We will have 32 session port, so I will divide by 2, so each CCM cluster will have 16 ports. Thanks for asking.

4. Is it necessary need to install gatekeeper in my situation? Can I use "inter-cluster trunk non-gatekeeper controlled"??

5. According "Cisco Unity Integrated with Multiple Cisco CallManager Clusters", H323 gateway is one of equirements for PSTN. I dont agree with that. I believe MGCP should be fine.

6. Thanks a lot!!!


Re: One Untiy intergrate with two CCM Clusters????

1. I am not getting a clear picture whether you are going to configure Voice messaging in failover mode (two unity servers, one backing up the other) or having two independe unity servers built and do some form of license pooling and split the users across both servers (same AD forest). If you are using Failover mode, you will need a separate message store.

2. You dont need digital networking if you are in failover mode. If you build two independent Unity servers, you will need Digital networking (dialing domains, locations defined in each Unity). Cross box login is supported starting with 4.04 and later.

3. If running failover mode, you cannot split 32 ports into 16/16. You have to buy another 32 port license (failover license) and also mirror the same number of subscriber licenses you have in primary Unity server.

If you are gonna use two independent Unity servers, you can split the licenses, but you will have to contact Cisco licensing team to do that. Never done this, so I am still unsure if they will let you do this. Email

4. YOu may or may not use a GK in this solution. You can set up ICT (Non GK) if there is a lot of bandwidth available. Its a good idea to have CAC implemented if you do a lot of Intercluster calling. I think there is a GK license that you may have to purchase to enable GK feature on a cisco router.


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Re: One Untiy intergrate with two CCM Clusters????


Thanks for your reply and sorry to confuse you.

Currently, we have one unity VM and 1 CCM cluster, in the future, we will have another new CCM CLuster.

The old unity(16 ports session) will be retired. The two new servers will be configure as Primary and Secondary (upgrade to 32 ports and failover licenses will be purchased also). The sales enginner did not buy Thrid server for message store, I have to tell them that.

Thanks again all


Re: One Untiy intergrate with two CCM Clusters????

You dont need to retire the old 16 ports. Instead you can get a 16 to 32 upgrade on those ports, give the new mac-address of primary server and get a new license for the primary Unity box. The part number for a 16 to 32 upgrade is UNITY-SVRLIC-UPG32

For the failover unity box, you will need to buy

a. 32 ports for failover - UNITY-FOVRSVR4-32

b. the same number of licenses you have for subscribers in the primary. (UNITYVM-FOVR-USR)


Re: One Untiy intergrate with two CCM Clusters????

Here is how you do two CCM clusters with one Unity.

See attached.

You will need additional ports if you need to keep the same level service on both clusters. (ports may be purchased 16, 32, 72 increments). And definitely more subscriber licenses. No other special licenses required.

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Re: One Untiy intergrate with two CCM Clusters????

Unity versions 4.04 and later also support Cross-server logon, where a subscriber in Unity A can call into Unity B and log in.

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