A push-to-talk communication device including an operating answer mode
indicates that operating answer mode to a Session Initiation
Protocol/Internet Protocol based push-to-talk network server. The method
includes employing as the operating answer mode of the push-to-talk
communication device one of an automatic-answer mode, an
always-automatic-answer mode and a manual-answer mode. A Session
Initiation Protocol/Internet Protocol core network is employed including
a Session Initiation Protocol/Internet Protocol push-to-talk network
server. The operating answer mode is indicated in a Session Initiation
Protocol message from the push-to-talk communication device to the
Session Initiation Protocol/Internet Protocol push-to-talk network server
over the Session Initiation Protocol/Internet Protocol core network.