The present invention is directed to the recovery of a call signaling
channel in connection with a realtime communication established using a
packet data network. Specifically, in the event of the failure of an
endpoint's current gatekeeper, this invention provides a fast mechanism
for searching for an alternate gatekeeper with which the endpoint can
re-establish its call signaling channel and hence can regain call
service, including call features on existing calls. In accordance with an
embodiment of the present invention, a lightweight registration request
message is sent on the RAS channel to an alternate gatekeeper in response
to the loss of an established call signaling channel, even though a keep
alive signal is not then due. The lightweight RRQ message may be sent to
individual gatekeepers on an alternate gatekeeper list, until a
registration confirmation message is received. Alternatively, a
lightweight RRQ message may be sent to all or a number of the gatekeepers
on the alternate gatekeeper list simultaneously. A call signaling channel
is then established between the first alternate gatekeeper to respond
with a registration confirmation message, or to a selected gatekeeper
where a number of gatekeepers provide an RCF message.