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Unity UM Redesign - 1 Unity, 2 Sites, 2 Exchange servers (across WAN)

Unity 4.2.1 Unified

Exchange 2003 SP2

I'm running into a redesign issue because of budget. Currently, I have this:

1 Unity (main office)

2 Active Directory Sites (main & branch office)

1 Exchange server (main office)

We're going to be installing a 2nd Exchange server in our branch office and I proposed adding another Unity server at the branch office. Management does not have the budget for another Unity server and asked that I have the branch office Exchange users use the Unity server in the main office. The WAN connection is 45Mbps DS3.

They proposed this design:

1 Unity (main office)

2 Active Directory Sites (main and branch office)

2 Exchange (main and branch office)

What sort of problems should I explain to management the branch office might experience by having their Exchange and Unity across the WAN?


Re: Unity UM Redesign - 1 Unity, 2 Sites, 2 Exchange servers (ac

You can do this fine. I have designed a couple hub and spoke Unity designs. Unity is at the hub, next to an Exchange server. The remote sites vary from 5 subscribers to 100. You just need the bandwidth capacity to handle CallHandlers and voicemails. If you are using UM, it's better because everyone will stream out of Exchange, rather than using Unity port and TSP. (Outlook/Exchange has the wav file, they use media player or the builtin outlook snapin to play the file)

If the remote user picks up the phone to check VM, then you need the QOS and bandwidth for this to happen. Design your WAN accordingly and you should be fine.

Have the secondary Exchange server is not a big deal. It is a little odd for Unity to have this because it's offsite. Cisco normally does not recommend this because the time required for MWI services, etc to read the Exchange databases for new/read messages. If the roundtrip times are slow for some reason, the MWI may or may not light the lamp. Sounds like your bandwidth is good, but still provision it accordingly for voice.

Create your Exchange servers and Site links. This will cut down on replications in AD, etc.

Hope this helps.

New Member

Re: Unity UM Redesign - 1 Unity, 2 Sites, 2 Exchange servers (ac

other than voice mail being unavailable without SRST and pots dial backup? ;)

Well if its a full T-3, and you have qos configured... I dont see much of an issue even with G.711 codec being used. Its more of a design issue... how are you going to support vm if the wan is down?

Can the remote router offer dial backup to voicemail?


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