Unity UM with hosted Exchange

[Tommer Catlin]

Hello all mighty Unity Wizards -

Anyone out there using Unity with a Host Exchange Solution? Our Exchange is hosted by HP in Colorado Springs, our office is in Oakland. Right now, we are looking at going to Voicemail Only, but are throwing around the idea of UM. But with the technical requirements for Unity and Exchange being located together I wanted to see other designs or companies using a similar model.

Any pros/cons, issues, etc. I know the bandwidth is going to be one issue. If a call comes in to CCM, it's is transferred to Unity to take the VM. So for every PORT on Unity, I would need to calculate VOIP bandwidth. But I am sure there is a slew of other issues I'm not thinking of.

Thanks much

[Brandon Buffin]

The Unity Design Guide says that the Unity server should be in the same network segment, site, and domain as the Exchange server. This is not always possible, but I think your situation would produce unacceptable delay for message retrieval, MWI, etc.

Cisco Unity Design Guide

http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_implementation_design_guide_book09186a008022f63b.html

Hope this helps.

Brandon

[Tommer Catlin]

Correct me if I am wrong. If the VM is recorded and placed in the Exchange store where the subscriber is, the user then has Outlook 2003 running in Cache mode. Outlook would then cache the message locally on the machine (Wav file) and then play normally. I can see how the MWI would have delays.

I'll check out the guide and see.

[Brandon Buffin]

That's true. Running chached Exchange mode also produces some delay in MWI. When you read a message in cached mode, the change is first written to your local machine and then to the Exchange server. Unity will not turn off the MWI until Exchange knows that the message has been read. Just something to think about.

Brandon

[Tommer Catlin]

So to create a high level layout -

HQ - 1400 users are using exchange that is Co-located in NJ (and connecting to NJ)

HQ - 1400 CallManager subscribers

HQ - CallManager servers onsite

NJ - Domino servers

NJ - Unity Servers

Links: HQ <------> OC12

I have seen this model in production with no issues, but wanted to have more input from others.

The caching is a great point. Points for you, because that could be an "annoying factor" But the way Exchange 2003 operates with clients could be a benefit or a burden if colocated. I'm not sure how the client is using Exchange also.. it may be going through RPC/HTTP which make this model... useless.