Hi, i'm running ccm 5.1(3) version in secure mode (encripting local calls), i 'have an intercluster trunk to a 6.0 ccm (secure mode too) , and i need to know if is possible to encript calls between them. I checked the security guide and i think it's possible using the ipsec module of the callmanager or making an ipsec tunnel with other equipment. I need to know if i can do it , no matter they are diffrent versions; or if there is another way. Thank you.
I would like into the latter option you mentioned which is creating a vpn type tunnel between the two. Since it's on the network layer, you won't have to worry about version compatibility in the future. However, keep in mind that you might have QOS issues with that solution.