Cisco Support Community
Community Member

UPGRADE CUCM 7.1.3 to 8.6.2A Best Practice Help!

We have a single publisher/subscriber running 7.1.3 as well as a single Publisher Unity Connection server running 7.0.2 and Cisco Emergency Responder 7.1.3.  There are several questions that I have pertaining to our production environment.  We have roughly 300 phones.  Can we do the upgrade to the CUCM servers while the CUCN and CER servers stay at said state versions?  What effects of the CUCN (7.0.2) and CER(7.1.3) running with CUCM servers running 8.6.2a?

2.  Do we have to upgrade all four servers at once?

3.  Can one PRI run two cluster environments running on two different versions?

Old is 7.1.3 and New 8.6.2a?

Cisco Employee

UPGRADE CUCM 7.1.3 to 8.6.2A Best Practice Help!


check the release notes for CUCM 8.6.2 and make sure UC and CER are supported or not.

if they are, you can only upgrade the CUCM vesion wihtout upgrading the UC and CER.

if you are running H323 than you have 2 cluster envirnoment but i dn know how you will route the same DID number.


Vipul Jindal

Hall of Fame Super Silver

UPGRADE CUCM 7.1.3 to 8.6.2A Best Practice Help!

Just to add for question 3 as Vipul said (+5) with H323 it's as simple as pointing different dial-peers to different CUCM servers, so you may need to break your DID ranges, or you can simply route all calls to one cluster and then transfer appropriate calls to another via Intercluster trunk, so this would not require H323 and would work with any protocol.

For question 1-2 see the compatibility guide for links to appriopriate UCON and CER compatibility information:



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