I have a customer that would like to know if they can use a different client with their OCS deployment? Is Office Communicator the only client that works with OCS or can they use other compliant clients. Is the requirement to be to the SIP standard? Thanks, Jazzy

While OCS and Exchange have some interdependencies, you might have better luck with this question in an OCS forum. Try here: http://forums.microsoft.com/TechNet/ShowForum.aspx?ForumID=1927&SiteID=17