Embodiments of the present invention provide a system, method, apparatus, means, and computer program code for facilitating or providing a back-up capability in a communication system and for improving availability and reliability of a distributed communication system. Switch over occurs from a main server to a stand-by server for supporting or facilitating calls having traffic routed across an IP network when the main server is disrupted or becomes unavailable. The main server initiates one or more signals provided to the stand-by server that inform the stand-by server of availability of the main server. When the stand-by server does not receive a designated number of the signals, or the main server fails to respond to a request or inquiry from the stand-by server regarding the signal, the stand-by server may initiate providing support for the calls previously supported by the main server and request call state information at the time of switch over from the main server to the stand-by server. As a result, the stand-by server does not need to receive call state information prior to the time of switch over.