IP Phone firmware compatibility

[guy.richard]

Hi,

I am planning an upgrade from CCM 4.2.3 to CUCM 8.5 on new servers.

I have upgraded to CUCM4.2(3)sr4b with 8.4.1 firmware, which can go to 9xx.

Connecting IP Phones (7911 and 7941/61) on CUCM8.5 Ip phones upgrade to 9.2.1S and then connect to CUCM8.5 that is ok.

My customer wants to test reverting to the old servers. On the 9.2.1 release-note I can read it is compatible with CCM4.x but reverting does not work, IP Phones do not register.

If I erase trust list then they downgrade and register but this solution is not suitable (1500 phones on 80 sites).

I tried the same on my lab with an upgrade to 8.0 with 9.0.2 firmware.

The problem is quite different: 7911 revert after a few mins whithout doing anything but 7941/61 do not, going on looking for XMLDefault.cnf.xml.sgn file on TFTP.

Can anybody tell me if this revert is possible or not ?

Guy

[Rob Huffman · Accepted solution]

Hi Guy,

It may be far easier to just set the Device Defaults on 8.5 for the 7941/61's

to 8.4.1 until you are sure that you won't be reverting to 4.2 Don't even start

the upgrade process until you have let things settle on 8.5.

Cheers!

Rob

[guy.richard]

Hi Rob,

Thanks for your answer. This seems to be a good idea.

I wonder if there is a document showing compatibility between firware 8.4.1 and CUCM 8.5 ?

In fact the biggest problem to do such a revert is the trust list downloaded by the Phone while it is upgrading and registering on the CUCM8. Is there an automatic way to erase the trust list ? or to put the files on CCM4.X TFTP ?

Guy

[wenqianyu]

I have tested back out to CUCM pre CUCM 8.0. Here are steps I follow:

Step 1     From Cisco Unified Communications Manager Administration, choose System > Enterprise Parameters  

                Set the Prepare Cluster for Rollback to pre-8.0 enterprise parameter to True  

                      If you try to login/logout, it will fail 

                      DO NOT RESET. IF Reset here, all phones are lost 

Step 2      Restart the Cisco Trust Verification Service on all Nodes  

Step 3      Restart the Cisco TFTP Service on the TFTP Servers  

Step 4      Reset all Cisco Unified IP Phones  

                     Reset from Enterprise Parameters  

Step 5      Reverse back to CUCM 715  

                First Node first. Login to RTMT for CUCM 7 to monitor other Nodes reboot 

                TFTP  

                Subs 1  

                Sub 2  

Step 6      Restart TFTP service on TFTP server  

Step 7      Reset all IP Phones  

Hope this helps.

Wenqian