I came across an issue regarding the forward on a Lync response group. There was a queue time-out enabled and set to “Forward to telephone number”. This field was filled with sip:+firstname.lastname@example.org (where domain.com was the SIP domain).
When a call came and hit the time-out, the call was forwarded to the number specified, but then an error was displayed on the client, on both Lync client 2013 and a Polycom Lync Phone Edition. The error was “the call could not be completed. Please try again later. The call could not be completed due to a busy network.“.
I started the logging on the Lync Front-End server and found the following error that was displayed:
ms-diagnostics: 1003;reason=”User does not exist”;TargetUri=”+email@example.com”
This is an expected error, as the user is not an existing user. But after this error, there was no SIP signal to the PSTN gateway for an outbound call. After some search on the internet, I saw this blog from Tim Day. This was exactly the same issue I was having. His solution sounded plausible, so I tested it, but with no luck.
I started testing with different Response Groups and found the problem. This specific Lync environment consists of multiple SIP domains. When a response group was made with a SIP domain that wasn’t the primary SIP domain, the problem existed. As there is no way of changing the SIP address of response group, I recreated the group.
After recreating the response group (workflow) with a primary SIP domain SIP address, the outbound call was made after the time-out was hit.