CME can be integrated with Cisco Unity, it is more or less as an integration with Call Manager except the fact that you must every setting in the CLI mode. Let’s see a kind of basic config:
! telephony-service voicemail 5555 ! ephone-dn 10 number 1234 call-forward busy 5555 call-forward noan 5555 timeout 10 ephone-dn 16 number 5566 mwi on ephone-dn 17 number 5577 mwi off ephone-dn 20 number 5555 name “VM-Port 1” preference 0 no huntstop ephone-dn 21 number 5555 name “VM-Port 2” preference 1
no huntstop ephone-dn 22 number 5555 name “VM-Port 3” preference 2
no huntstop ephone-dn 23 number 5555 name “VM-Port 4” preference 3
So you can easily see that your config is trying to match the Unity port name and this is done with the command vm-device-id <<string>>. It helps also to register with Unity where you need the deviceId instead of a mac-address.
Survivable Remote Site Telephony (SRST) is a feature which ensures that IP Phones can continue to function even if they are unable to communicate with Call Manager. During a failure, Cisco IP Phones register with the local SRST router which provides Call Processing and Control.
With the Connection Monitor Duration, Cisco IP Phones do not fail back immediately to ensure that the Call Manager in question is back online and is stable.
Here is also another presentation of Cisco SRST ( Cisco video)