I have a client running the above PBX using Avaya Index Voicemail. The voicemail system has had a number of issues recently and they are looking to replace it.
Next year my client will be migrating to CM5.x however have no budget for it this year. They do have budget however for a new VM system.
The customer has a spare ISDN PRI card in the PBX that supports Q.931 and an existing 2821 ISR with DSPs and VWIC2-PRI module.
I'm pretty comfortable that I can establish a Q.931 trunk from the Index down to the ISR and route calls between them.
If I install Unity Connection (are they any advantages at this level with full Unity?) on the LAN, can I use UC as the voicemail system for the Index? The current voicemail is only a single extension number on the Index, so I can route this number down the Q.931 trunk to the ISR, and from there over to the UC Server.
I can't see why this wouldn't work as this only needs to provide basic voicemail services (no autoattendant or similar). Are there any obvious problems that I need to look out for. What would I need to do to pass MWI back to the Index so that it can light the lamps on the phones?
Thanks for any assistance or pointers.