IMP between 2 clusters in same domain

[sujith.poojary]

We have customer who we have setup new CUCM-IMP cluster for. They share domain and AD with their parent company who already have their own CUCM and IMP cluster . Now Customer wants IMP enabled between users from these two different clusters. Each company also has their own expressway clusters. Is it possible to have chat and presence feature enabled for this scenario?
I will attach a diagram which shows the set up . Please assist.
CUCM cluster 1 version 11.5
CUCM cluster 2 version 12.5

[Jaime Valencia]

Yes, you configure either inter-cluster or federation between them, review both options and then determine which one would work for your scenario.

[Maren Mahoney]

Jaime is right. Here are some docs to get you started:

Interdomain Federation Guide for IMP 12.5(1) 

Configuration and Administration of IMP 12.5(1) - Configure Intercluster Peers 

Maren