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Unity Accross WAN

5000 Unity Users. Unity 4.0 UM at one location. Exchange is located across WAN (OC3 connection). Would Unity demolish that OC3 connection. What are the pitfalls?


Re: Unity Accross WAN

Unity is extremely sensitive to delay when contacting an Exchange server. 155.52 Mbps is a lot of bandwidth but I am wondering what else you have running over it. You’re not planning to have an OC-3 just so you can have Unity across a WAN link, right? What kind of round trip delay do you have over this link and what is the current utilization? How reliable is the link? Where do you plan on putting the partner Exchange server? Would you be willing to dedicate bandwidth (>25mbps) for the traffic between Unity and Exchange?

As a rule you want to shy away from WAN links but your situation could be different. If you can provide a little more data I will let you know if I think this could fly.




Re: Unity Accross WAN

Well the documentation says you need 24k per mailbox so:

5000 users x 24k = 120mb

Is that suggesting you need 24k per mailbox at all times. What exactly is the traffic between Unity 4.0 and the Exchange besides typical Active Directory, and Sql traffic. Exchange server needs to stay in Colorado and Unity needs to stay in Chicago. CallManager is not involved yet. We need Unity to be in Chicago to light the MWI for the PBX phones.


Re: Unity Accross WAN

You state the Unity server needs to be in Chicago only to light MWI lights, but you also state that CallManager is not involved yet. I don't know from this whether or not you would be able to efficiently reach the Unity server to actually leave voicemail (VoIP or otherwise) from Chicago if it were located in Colorado.

If the only thing tying your Unity server down to Chicago is the MWI signalling, it should be possible to tunnel an async serial SMDI link over IP for next to nothing in bandwidth cost. I'm not sure if that's ever been recommended or tested, but I can't think of a reason why it wouldn't work. A thorough lab test and extensive consultation with your local Cisco representatives would be strongly recommended.

Unity logs into every subscriber's mailbox via MAPI , just like Outlook. As such, it's getting notifications of new messages and other mailbox traffic all the time for every subscriber, not to mention actual voicemail traffic. You have 5,000 users. You really need to get Exchange and Unity close together network-wise. If the above doesn't help, we need to know more about your network and your voice/PBX topology to figure out how to make that happen.

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