I have a working Lync 2010 environment which is currently successfully making PSTN calls through a SIP trunk on a OCS 2007R2 Mediation server which is in co-existence.

The problem I have is with external Direct Access clients, PSTN calls fail. I have verified that the Lync client is logging on through the edge server as an external client. I have also verified that in the same remote location a non-DirectAccess client works perfectly.

I have blocked the relevant DNS records on the UAG server so they correctly get resolved by our external DNS, not the internal.

The following could be relevant;

• I don't recall this happening when the OCS 2007 R2 Edge server was in co-existence. (We now use Lync Edge server).
• I need to do more tests but I suspect that this is only happening when DA is using IPHttps, not ISATAP.

I have resolved this.

I needed to exclude the Lync Pool internal fqdn from being resolved by UAG DNS, this way the Lync Client didn't pick up the internal pool from _sipinternaltls and try and logon as an internal user.

 

• Marked as answer by Tim Chapman Sunday, December 26, 2010 8:16 PM

Hi Tim,

I know this is an old post, but i'm having the same/similar issue. I'm using 2012R2 DirectAccess with Windows 8 and 8.1 clients. I've tried adding the internal Lync server DNS names to the exclusions list on the client via the DA client GPO, but I still get the problem where an external client can login to lync, send IM's but cannot connect a voice call (either PSTN or Lync to Lync). It'll ring at the other end, but when they answer it says "connecting" and then drops after 10 seconds or so. Any ideas?

Cheers

Darren