Try this:

term mon

Then register your CIPC that doesn't work. It will indicate that a particular ephone number has registered.

Likely, you do not have a DN configured under that ephone. This could have happened if you mis-typed or misconfigured the MAC address.

Just find the ephone number it is regstering as, and add the dns to it.

-nick

I am trying to auto register a fresh IP communicator which the mac address is not configured already.

when a fresh IP communcator is trying to register,the event shows the ephone number.but if we login and look into that ephone number,there is no mac address.I need to add the mac-address manually to make it work.