OCS 2007/Lync 2010 is a great unified communications product, but one limiting factor has been the inability to connect devices via UDP. Microsoft says that they limit the connections to TCP only devices for security purposes. This article is not a commentary on why, but a discussion of how to overcome this limitation. Also, this shows 2 methods to connect to asterisk, but the sip proxy should work with many other IP PBX systems as well, and almost everything can connect to asterisk, so with these tools we should be able to connect to just about everything out there.