Wednesday, December 18, 2013

Lync 2013 - Calls dropping with error “SIP/2.0 487" Request Terminated” after successful connection


Calls dropping with error “SIP/2.0 487" Request Terminated” after successful connections. In order to support fast failover, there is a setting in Lync called “enable outbound routing failover timer”. This trunk setting requires that the SIP trunk notifies Lync within 10 seconds that it is processing an outbound call.  This setting can and does cause problems on networks where latency delays the response time or the gateway takes longer than 10 seconds to respond. Some SIP trunks will either not provide this notification, or is not able to get it back to the Lync server within 10 seconds. In this case the call will drop in about 10 seconds and a “SIP/2.0 487 Request Terminated” will appear in the Lync server SIP transaction logs.
To resolve this issue uncheck the box “Enable outbound routing failover timer”. This setting is located at LSCP>Voice Routing>Trunk Configuration