Hi Keif,
One of my favortie quote is "This is not a bug... this is a feature !".
Actually, in your situation this quote is right... By default, MOC 2007 R2 restricts usage of Secure RTP (SRTP) communications between endpoints (here, between Exchange and MOC R2). Configuring Exchange's Dial Plan for OCS R2 in Secured mode enforces usage of SIP/MTLS and SRTP...
MOC R2 also enforces by default Strict DNS Name checking, which might cause sign-in issues with Live Meeting 2007 (make sure you are using build 114 for both LM console and LM Outlook Add-in) in split-DNS scenarios (eg: your pool is ocspool.domain.local and you SIP domain is domain.com). To avoid this, make sure your OCS R2 certificate includes sip.domain.com in its SAN attribute and that your SRV records (_sip._tls.domain.com and _sipinternaltls._tcp.domain.com SRV records both point to sip.domain.com). That said,
Hope this helps/enlights your points.
Benoit.
Benoit Boudeville - Avanade France & Belux
http://unifiees.blogspot.com