Patent ID: 8526592

Claim:
A system, comprising: a call controller configured to: receive a refer message configured to transfer a first endpoint of a call session, the call session being between at least the first endpoint at a first communications device and a second endpoint at a second communications device, the refer message indicating to transfer the first endpoint from the first communications device to a third communications device; subscribe the first communications device to notification messages associated with the referral of the transferred call session, the subscription to the referral extending beyond the call transfer until termination of the call; receive a subscribe message from the first communications device configured to refresh the subscription; determine whether the subscription has expired, and if so whether the subscription has expired within a predetermined amount of time if the subscription has not expired or if the subscription has expired within the predetermined amount of time, refresh the subscription; otherwise, reject the refresh of the subscription; and send, if the subscription has not expired or is refreshed, through the subscription to the first communications device, a notification message indicating termination of the transferred call.