http://blogs.technet.com/greg_katz_-_messaging_in_education/archive/2008/06/05/ocs-sip-over-udp.aspxWhat’s the overhead? What’s the argument. This is a very interesting blog that shows how the least common denominator in SIP communications is TCP but how the argument for UDP has continued over 20 years. http://communicationsserverteam.com/archive/2008/05/23/196.aspen-USCommunityServer 2.1 SP1 (Build: 61025.2)