HI All,

I have deployed Lync Front end & Mediation server collocated, I have also a pstn Gateway which handles my PSTN calls through one T1/E1.

Now when I make ISD calls it takes 10 seconds after that calls get cancelled by Front end server.

I am not sure that wheater it is telecom provider issue, or Phone usage.

Early media and Early progress is disabled on gateway.

what should be the issue here.

thanks

Have you enabled the Edge in the topology builder but not deployed or configuration it?  Try unchecking the "Enable outbound routing failover timer" on the Lync trunk configuration.

What do the outbound normalization rules look like for calls going to the PSTN? 

Did you assign the DID phone number to Lync users?

Please check the voice policies and PSTN usage records and voice routes are set correctly.

http://technet.microsoft.com/en-us/library/gg398272.aspx