Recently after implementing my Edge services in OCS we started to federate with our partners and all seemed rosy to start off with. Then all of a sudden we could only send IM’s out and could not receive any back. External partners would send us an IM we would get the OCS toast but when you accept it the conversation was blank.
Well after much checking and doubling checking everything!!! It turned out that the primary EDGE certificate that had our domain name was the incorrect way around as our users SIP address end in a different domain name. So if anyone else is working in a multi domain environment make sure the primary name or your certificate is the same as your users SIP address!