I upgraded publisher to 4-2-3-sr2b. All OK. When I attempt to upgrade subscriber, it fails, and now these errors are all over the application logs of both servers...
Event Type: Error
Event Source: Cisco CallManager
Event Category: None
Event ID: 3
Time: 8:07:25 AM
Error: SDLLinkAppProtocol - SDL Link Connection Refused.
Remote Application Link Protocol Version: D
Local Application Link Protocol Version: C
Remote Node ID: 1
Remote Application ID: 200
Remote Application Version: 4.2(3.13216)
App ID: Cisco CallManager
Cluster ID: CM_Cluster
Node ID: xx.xx.xx.xx
Explanation: This alarm indicates that the local Cisco CallManager is unable to establish communication with the remote Cisco CallManager due to a protocol version mismatch.
Recommended Action: Determine the release numbers of the local and remote Cisco CallManager servers. If the releases do not match, it's possible that the local and remote Cisco CallManager servers cannot communicate due to protocol changes. To correct the problem, upgrade the appropriate Cisco CallManager so that the versons of the local and remote Cisco CallManager servers match..
I understand what it means, and by comparing the application version tags of each corresponding error, I can see the versions are different, but the solution offered is upgrade the server, which I can't do.
I've got CSA and anti-virus disabled, I tried rebooting everything.
Any suggestions? I can't find anything on this error.
Edit: I should mention, calling functions from each office are working, but neither site can call the other directly. Fast busy when dialing the extension of sub from pub or vice versa.
I recommend you to uninstall the SR on both servers, leave them as plain 4.2(3), then run the DBLHelper to check the replication, if necessary try a Republish. Once you have green faces and SDL link is back up then upgrade to the same SR on both servers.