We are planning to implement an enterprise level exchange server 2007 for hosted mail services & mobile mail access for hand held devices. We have thought of scaling out the 5 server roles in exchange 2007 probably in to 3 high available clusters. Cluster1 Edge Transport, Cluster2 Mailbox & Client Access and Cluster3 Hub Transport & unified Messaging. We want to integrate Office live communication 2005 or Live communication 2007 in to this scenario so my question is whats the recommended location for the Live communication server? Is it ok if we run it together with the Unified messaging system or somewhere else? And where can we run the DC? Is it ok if we run it one of the above 3 clusters? Any ideas or comments are highly appreciated. Thank you.

Lakshantha, Sounds like you will have a very solid infrastructure for Exchange 2007 (depending on the size and usage of the company, maybe even a little overkill). The major advantage of Exchange 2007 is that by separating the roles, it allows for a highly redundant, scalable messaging system. Based solely on your discription, you should have little to no problems integrating Live Communication Server on any of the Transport servers. Live Communication Server is not very overhead heavy and runs on minimal load. Here's an overview of the LCS deployment requirements: http://office.microsoft.com/search/redir.aspx?AssetID=DC011620951033&CTT=5&Origin=HA011526621033 or for all the LCS docs: http://office.microsoft.com/en-us/communicationsserver/FX011526591033.aspx#6 Cheers, -Allen Firouz

Something about Exchange 2007 HA must be tonotice as below Edge Server Role HA is use DNS Run Robin,Edge SMTP not support NLB Client Access Server Role HA is use NLB Hub Transport HA is deploy more than one in the same AD Site Mailbox Server Role HA can be a LCR,CCR or SCC.When you Deploy CCR or SCC just only Single server role can be deploy on box! UM Server Role HA is same as HUB Transport server role. BR, Jammy