A summary of the issue is that Freeswitch sends Jitsi an UPDATE Request. There is no method processor that appears to handle the UPDATE request, so Jitsi defaults to setting the Peer State to FAILED with a 501 Not Implemented error, but doesn't return the 501 response back to Freeswitch. Freeswitch subsequently sends me another 4 UPDATES. As a possible enhancement, I opted to explicitly handle UPDATES in the class OperationSetBasicTelephonySipImp. The enhancement does not set the Peer State to Failed, and does send back a 405 METHOD_NOT_ALLOWED. As a side point, Freeswitch completely ignores the Allow Header from which I explicitly preclude the UPDATE method and continues to send UPDATES. Is it reasonable to handle the UPDATE request in the OperationSetBasicTelephonySipImp class, or should that implementation take place elsewhere?