Hi

I am having 4 numbers of ATA 186 out of which 2 had been configured on UCM 6.0 FAX is connected to one of the ATA and a analog phone is connected to another ATA. The problem is

When someone calls from outside sometime the phone/Fax rings, and sometime they get the message “please check the number, it does not exist “ and this is intermittent, that is it 15 to 20 minutes.

The internal calling is working fine [extension to extension calling]

I have Enabled debug on the voice gateway, at the time when there is problem, call is coming up to the router and it says “Unallocated/unassigned number”.

please suggest.