Event ID: 1400, The following UM IP gateways did not respond as expected to a SIP OPTIONS request.

In relation to my previous post regarding Exchange2010 integration with Lync 2010, I encountered Event ID 1400. The certificate issued in the Exchange UM Server was not using its FQDN (EXCHANGE.domain.com) as the Subject Name (SN), instead the SN was owa.domain.com. The owa.domain.com certificate was issued before in the Exchange Server by the Exchange Admin. It was not me who issued it, but I have to be honest, it took me the whole day to realize that I need to check the Exchange certificate's details. Good thing I did!

Event ID: 1400 Source: MSExchange Unified Messaging
The following UM IP gateways did not respond as expected to a SIP OPTIONS request.
Transport = TLS, Address = lyncfe.domain.com, Port = 5061, Response Code = 0, Message = This operation has timed out.

Symptom
UM Cannot make a TLS connection to the OCS 2007 Server
Cause
The UM server was using a wildcard cert. This type of cert cannot be used for TLS connectivity with OCS
Resolution
Re-issued a cert with the fqdn of the UM server as the subject name.


The resolution? I created a new certificate and assigned it to the Exchange UM role only with the FQDN as its Subject Name. :)