Unity--Remote Message Stores

wrkemmer · ‎03-08-2004

I'm concerned about using Unity with remote message stores and I'm wondering if someone could comment on my situation. We are going to install Unity into an existing Exchange organization at the central site, which is where all of their Exchange users currently have their mailboxes. There are 4 branch offices, all tied to the central site by T1 or fractional T1 (768k) links. As stated, all mailboxes are currently at the central site.

Their Exchange admin is pushing an extension of their current design where the 2 bigger branch offices will get their own Exchange servers onsite and will move the subscribers at those two sites to the local Exchange mail store. His thinking is that if the WAN link ever goes down, at least these users will have local messaging. These remote stores will be also be the Unity mailboxes for these subscribers. After reading the Unity design guide I have been pushing him to keep mailbox stores centralized (for bandwidth considerations), but I think that he is leaning toward implimenting his design.

I guess I'm wondering how Unity handles retrieving and playing messages in this situation, and how much bandwidth over the WAN is consumed in the transaction.

The subscriber will call into Unity and establish a session, and Unity will connect to the mailstore to retrieve the messages, but I'm not sure how exactly this process occurs with a remote mailstore.

I'd appreciate any comments so that I can give my customer accurate information.

kechambe · ‎03-08-2004

The design guide is going to be updated very shortly to reflect that beginning with the release of 4.0(3) WAN links are explicitly not supported between Unity and Exchange. The 4.0(3) release notes have a blurb on this:

http://www.cisco.com/en/US/products/sw/voicesw/ps2237/prod_release_note09186a00801b92bc.html#383616

One of the main reasons for this is CSCea68581 which is noted in the 4.0(3) release notes as well.

So it is not supported to have Unity access mailboxes out at those remotes sites.

Thanks,

Keith

wrkemmer · ‎03-09-2004

Keith,

Thanks for your reply--it has helped push the customer away from that configuration. As a follow up, are there any recommendations for designing a Unity system with remote locations? I have thought of a few things:

-move all subscriber mailboxes to the central site.

-keep email boxes at remote sites, but give them a voicemail box at the central site (which pretty much kills the unified messaging model)

-put a Unity server at each site in some kind of clustering configuration (I don't even know if this is possible, and it is certainly out of price range.)

Other than those, are there any supported designs for WAN configurations?

Again, I appreciate all the help.

wrkemmer · ‎03-09-2004

Just as an addition to this scenario, if we are forced to try to make this work over the WAN, are there any other suggestions to help this happen, other than the obvious qos policies that would need to be in place?

Thanks again.