This article is another one spawned from running into an error that google nor bing had any useful result on. Therefore, this is now something which is better than nothing.
While migrating an AudioCodes Mediant 1000 from one Lync branch server to another I noticed the following error captured in the syslogs post migration:
!! [ERROR] Rejecting call from UnRecognized Source address – 10.x.x.x:55555
I noticed for each IP noted as the source address the error repeated roughly every 60 seconds so believed it was an OPTIONS request from a non trusted source. In my situation it was NOT a call attempt/INVITE coming from the source IP in the error. Depending on your situation you could either ignore the error if you don’t care about the source IP, have the source IP stop trying to communicate with the gateway or add the source IP in the Proxy Sets Table. I chose option 3 as it was still in use.
Enjoy the day.