Patent ID: 8582544

Claim:
A communication device, comprising: a memory to store computer instructions; and a processor in communication with the memory, wherein the processor, responsive to executing the computer instructions, performs operations comprising: transmitting a first session-initiation-protocol registration message to an internet-protocol-multimedia-subsystem network; receiving a first acknowledgment from the internet-protocol-multimedia-subsystem network indicating that the communication device has registered with a primary communication resource in the internet-protocol-multimedia-subsystem network; transmitting a second session-initiation-protocol registration message to the internet-protocol-multimedia-subsystem network, wherein the second session-initiation-protocol registration message comprises an indicator for registering the communication device with a secondary communication resource in the internet-protocol-multimedia-subsystem network, the indicator including an identification that the secondary communication resource is to provide backup communications without initiating a de-registration process thereby causing a prevention of de-registration from the primary communication resource in the internet-protocol-multimedia-subsystem; receiving a second acknowledgment from the internet-protocol-multimedia-subsystem network indicating that the communication device has registered with the secondary communication resource; and transmitting a session-initiation-protocol-origination message to the internet-protocol-multimedia-subsystem network to establish a communication session with a second communication device, whereby the session-initiation-protocol origination message is processed by the internet-protocol-multimedia-subsystem network by way of the secondary communication resource in an event that the primary communication resource is unavailable.