I am a newbie to cisco CM and I have recently do an upgrade. I have two servers 1 PUB and 1 SUB. So I upgraded the PUB first and do a testing.I notice that phones connected to PUB could not call on the phones registered on the SUB. Is there an issue in mismatch of patch on server that's why it the phones behave that way. Do I need to complete the upgrade before I test.
CM4.1
patch sr5d
CM4.1
patch sr5d