Centralized Unity Voicemail Redundancy

[TJaw14]

We are interested in building a centralized unity voicemail that will supply voicemail services over our MPLS WAN. What is the best approach to redundancy with this build out? Would it be best to set up an additional Unity for failover in another location? I am even wondering if it would be best to set up Unity Express in the remote offices, but I am not sure if the Unity Express product will support bilingual voicemail. One of the offices is in Montreal, so the back up would need to provide voicemail in english and french. Anyone have any advice here??

 

[pndscm]

What type of phone system will Unity be supporting? I have a customer with multiple MPLS sites with a Centralized Unity voice-mail system with a CallManager. Each remote site on WAN failure goes into SRST mode. When the site goes into SRST mode and someone presses the Voicemail button, the router dials out the local lines and connects the call back to the Central site Unity. However they can't receive voicemails from local people during that time as there is no local Mailstore. If you need local mailstore during failure you are probably looking at a Unity server and a Mailstore in the remote with whatever Mailstore networking needed to delever the messages. I'm not sure if Unity Express can network with Unity yet. Also don't know if CUE supports multiple languages.

 

[HmmG3]

If you install a Unity failover server, it must be in the same location as the primary Unity server. They aren't like the CallManagers where they can function independently during a network disruption. The failover is intended to take over only when the primary suffers an internal failure. When you have two Unity servers, you will also need a message store (Exchange or Domino) on another server. However, if the message store goes down, the Unity will still handle calls and let callers leave messages. You simply can't check any message that was stored on the message store until it's restored.

If you are prone to frequent WAN failures, then you will probably want a dedicated Unity for that site. I haven't worked with Unity Express, so I can't answer those questions. Sorry.

 

[MG2005]

If you have Layer 2 connectivity (like Metro Ethernet) or 45MB or better redundant links between your remote sites, you can safely put a Unity failover server across the WAN

We have this between our NYC office and NJ DR colo and it works great

Longer distances...or less bandwidth...not sure

Not sure what Cisco supports either

 

[pndscm]

Cisco says 100 MB link between Unity and the mailstore is all that's supported. Not sure that link between failover servers has been mentioned in the CUDN course I'm taking. But if they share the same mailstore that pretty much limits where they can be located.