Abstract: A method for routing calls in a packet-based network includes receiving a call request at a first call manager from a device that is coupled to the packet-based network. The call request includes a telephone number associated with a plurality of telephony devices that are coupled to the packet-based network and that are controlled by a number of call managers. The method also includes determining a line control process associated with the telephone number that is included in the call request and communicating the call request to the line control process. The method further includes determining a device process controlling each telephony device that is associated with the telephone number included in the call request and communicating the call request from the line control process to the device processes.

Abstract: A communication system includes a controller for managing a number of communications devices. The controller receives registration requests from the devices and selectively registers the devices based on various factors. The controller may support a token registration process by which a device requests a token and, in response to the controller granting a token, registers with the controller using a token registration request.

Abstract: Registering with a call manager includes connecting to a first call manager and a second call manager. The endpoints register with the first call manager and send keep-alive signals to the first call manager and the second call manager. If a failure is detected in the first call manager, the system initiates a failover process. The endpoints re-register with the first call manager when the first call manager regains operability.