Retrying a Request


If the Unified Messaging (UM) server returns any failure response, as described in section, or if the Unified Messaging server timer expires, the next UM server in the list MUST be selected and the request MUST be routed to that server.

When selecting the next UM server, the UM server version and ordering to UM servers restrictions specified in step 7 of section 3.1.5 MUST be followed<11>.

If all servers in the list have been attempted, the call SHOULD be terminated with a response code 480.<12>

If the request was routed to a new UM server, the Unified Messaging server timer MUST be restarted.