Hello,

I'd like to ask if anyone of you has similar problem: 

We're using TMG 2010 and now we're testing Google Hangouts in our network. TMG is our outbound proxy. Shortly after strarting a meeting (30 sec up to 1 minute) we get a Hangout error #51 ("try again later") or there is a black screen with "Call has ended" information.  We had no luck when searching through TMG logs - nothing seems to be blocked and we've not added any Google IP, URL or Netblocks to be blocked. Popular browsers were tested (IE, Chrome, FF,  Opera, Safari) with the same results. On other network everything works just fine (without TMG), but other test TMG proxy shown same results. Funny thing is that when testing directly on TMG server - Hangouts work like a charm. For the tests purpose we also allowed all Outbound traffic with no luck.

Any thoughts / ideas on this?