How to Establish a call between two seperate CUCMs

[Arun Sai]

How to Establish a call between two seperate CUCMs ?

CUCM version 6.1.2

Can somebody help with the steps. I am using 7965 and 7921 series IP phones at both locations.

[Vivek Batra]

It's simple. Although you can use H.323, but I will recommend to use SIP.

Create SIP trunk in each server and point it out to each other.

Create desired route patterns and point it to route group (/route list) having respective SIP trunk.

You can create region if specific codec is to be used between the clusters.

You may need to create partitions/CSS and to be assigned at various levels depends on your dial plan design.

- Vivek

[Chris Deren]

Vivek,

As much as I prefer SIP over ICT on newer versions of CUCM, since he is running 6.1 ICT would be recommended. In fact SRND states to use SIP instead of ICT if both sides are version 8+.

[Vivek Batra]

Thanks Chris for highlighting this information as I've started working on CUCM with 8.0+ and was not aware about this recommendation. 

- Vivek

[Jaime Valencia]

+5 to Chris, we only recommend SIP trunks instead of ICTs when working with 8.5+ releases, in any previous release, we still prefer ICTs.

[Gordon Ross · Accepted solution]

Assuming there are no firewalls, etc. between the two clusters...

First you need to create an Inter-Cluster trunk. In CCMAdmin, go to Device -> Trunk -> Add new. For Trunk Type, select "Inter-Cluster Trunk (Non-Gatekeeper Controlled)"

Fill out the relevant fields. Fields to look out for include:

• Device Information:
  • Device Pool
  • Location
• Call Routing Information
  • Inbound Calls
    • Calling Search Space
• Remote Cisco Unified Communications Manager Information
  • Server IP Address/Hostname

Do Save then Reset.

This tells the two CUCMs how to talk to each other. Now you need to say what is at what CUCM.

There are two ways to do this. The simple way is: (Again in CCMAdmin) Call Routing -> Route/Hunt -> Route Pattern

Click "Add New"

For the Route Pattern, put in the number pattern for numbers at the other cluster (e.g. 4xxx is for numbers 4000-4999)

Specify your partition.

For Gateway/Route List, select the trunk you created above.

Hit Save.

Make sure you do both the trunk and the pattern (Swapping the necessary parameters) on both clusters and that *should* be it.

This is the basic getting-you-started configuration. There are many enhancements you can make to this setup.

GTG