I've got the mobex ext. to work for internal calls only & does NOT work for external calls. if i dial 205 it rings both the ext & the cell. but if i call the DID directly i just rings the digital phone only. So I'm not sure whats missing here

. I'm trying to do this with just MOBEX & NOT executive MOBEX.
its a 7100 v4.46d, with SIP trunks, with MGI channels & with NO OAS card.
thanks