SIP/2.0 488 Not Acceptable Here
I was bringing up a new SIP trunk recently. After some SIP Invite manipulations we got outbound calls working. One would think inbound calls would be pretty straightforward.
Sadly, no.
I kept seeing this message in the Lync logging tool and Googling provided little assistance:
<?xml version=”1.0″ encoding=”us-ascii”?><reportError xmlns=”http://schemas.microsoft.com/2006/09/sip/error-reporting”><error callId=”2085379370307201314329@1.1.1.1″ fromUri=”sip:+13175551212@flinchbot.com;user=phone” toUri=”sip:+13455551212@flinchbot.com;user=phone” fromTag=”1c2085431640″ toTag=”” requestType=”INVITE” contentType=”application/sdp;call-type=audio” responseCode=”488″><diagHeader>10013;reason=”Gateway peer in inbound call is not found in topology document”</diagHeader><progressReports /></error></reportError>
Ummmm. That’s a lie! My gateway most assuredly resides in the Topology. Just for fun, I added the PSTN gateway a second time by IP address in addition to FQDN. This absolutely failed to fix the problem.
Long story short: This message is a little loose in what I think “not found in topology document” means. If I stretch the definition to mean “not found in topology document specifically as you defined it” then that might have been a bigger clue.
The fix was to set the Gateway to TCP (from TLS) to match the configuration within Lync. Once that was fixed, calls came in just fine.
Update: I saw this again. This time, the gateway was defined in DNS but the DNS address didn’t match the IP address of the gateway. So the gateway was sending correctly to Lync, but Lync was rejecting it because it didn’t know about this gateway. Putting the correct entry in via the HOSTS file fixed this in the short term. Long term – update the DNS entry.
