I have successfully integrated Unity 7.x with two clusters
Cluster 1 Comprise of two CUCM server (Two Subs)
Cluster 2 Comprise of one CUCME.
I am using the CUME in SRST mode to cummunicate with local Unity 7.x server when CUCM cluster fails or WAN goes down. Everything seem to be working fine, except I don't quite understand how my voice mail ports are been used.
I have 32 voice mail ports, I assigned the first 21 for answering calls and port 22 and 23 for MWI dial out and configured this as per Cisco document when integrating with Unity. So my first 24 ports is for Unity 7.x to CUCM integration.
The other 8 ports I have configured for the CUCME integration, using 6 to answer calls and the last 2 fo MWI, so port 25 - 32 are assigned to the CUCME cluster in Unity.
In CUCME/SRST mode if I access unity i see port 25 been used which is expected, as port 1 - 24 are no longer registered with the CUCM cluster. What gets me is that when i leave a message and the MWI comes on, I see port 24 turning it on and not port 32. So basically I have unity port 23 - 24 turning on MWI when CUCM Cluster is available and have port 31 - 32 for MWI when in CUCME/SRST mode.
It is working, but want to know why it is behaving this way and if this is the best Cisco recommended way to set this up