I have the following scenario, where I have three Sip phone extensions. (For ex 2222, 4444, 5555)
Two of the extension (i.e 2222, 4444) are configured in cisco UCM and third extension(i.e. 5555) is not configured with UCM.
When I send registration request for the first two extension(i.e 2222, 4444) to the UCM, the Sip registration is successful and Sip subscription is also successful. But when I send a Sip registration request for the third extension(i.e. 5555), I get the error saying the 404 not found. Which is correct behaviour, as the third Sip extension is not configured in UCM.
Now, after sending the Sip 404 not found, the UCM sends a Sip Notify with subscription terminated to the other two extensions. Is this correct behaviour ?
Why should registration failure of a dumb extension trigger a Sip subscription termination of all the other extensions? Am I missing something. Please help.