Not sure why this behavior started as it hadnt been doing this. 8 phone lines across 4 linksys spa2102 ata devices connected each line to its own extension on 3cx. The extensions are configured in 3cx with an external mobile number and are set to ring both the mobile number as well as the local extension simultaneously. Both ring into the system, however if the mobile external phone answers the call, the internal extension just keeps ringing until you anwser it and hang it back up. It seems that the ata device is not recieving the update that the call has disappeared from the system. System has been in place for months and has run trouble free until now. the bahvior change does coincide with a failure of the pbx's isp link as. Since the system was temporarliy down we had also brought the server up to version 11 of 3cx. Not sure whether this has anything to do with this or not. Wondering if anyone might have a thought on this.