The last blog was about URI Dialing at the same cluster which an easy step https://ccieroot.com/2014/10/30/uri-dialing/
But when it come between cluster there is another new feature Called ILS “Inter-Cluster Look-up Service”
Inter-Cluster Look-up Service (ILS) is a cluster-wide service in CUCM that when configured on and between CUCM clusters, synchronizes information throughout the “ILS Network”.

So after finishing configure the Basic URI and made Sure it working we start next step by configure the trunk between both publisher

Go to Device – Trunk Add New and choose SIP Trunk and the Device Protocol also SIP and here is the final Look

 

 

 

 

 

 

If you want to use ILS to support intercluster URI dialing, check the Exchange Directory URI Catalogs with Remote Clusters check box in the Intercluster Directory URI Configuration window.
go to Call Routing – Intercluster Directory URI – Intercluster Directory URI Configuration and check the box and choose a name

 

 

 

 

 

Before you start to configure the ILS go to the Enterprise Parameter – Change the name of  Cluster ID From StandAloneCluster to What ever name you wish in out case it’s CCIEROOT

 

 

then go to Advanced feature – ILS Configuration
and make your Publisher as the HUB and configure password and press ok but don’t put IP in the field of Registration Server

 

 

 

 

 

 

 

in the Other Server you configure it as a spoke and put the IP of the hub in the Registration Server

 

 

 

 

 

 

Then Configure the Route Pattern by going to Call Routing – SIP Route Pattern
from CCIEROOT To ATS and in ATS sever you configure a SIP Route Pattern From ATS to CCIEROOT were the IPv4 Pattern is to our ILS URI Configuration name which was MOTO.LOC

 

 

 

 

 

Now you can test the call and it Succeed Between Cluster