US Patent 9602556 PacketCable controller for voice over IP network

Disclosed herein are system, method, and computer program product embodiments for an access gateway control function server to convert between network-based call signaling messages and session initiation protocol messages. An embodiment operates by receiving in a first access gateway control function server, a first session initiation protocol (SIP) message sent from a first device and converting the SIP message in the first access gateway control function server to a first network-based call signaling (NCS) message to be received by a second device.