The present document is a multi-part deliverable belonging to IPCablecom. The present part (part 4) specifies a profile of an application programming interface, Media Gateway Controller Interface (MGCI), and a corresponding protocol, Media Gateway Control Protocol (MGCP), for controlling Voice over IP (VoIP) embedded clients from external call control elements. The MGCP is based on a call control architecture, where the call control "intelligence" resides outside the gateways and is handled by external call control elements. The profile, as described in the present document, is referred to as the Network Call Signalling (NCS) Protocol.

Annex B of the present document specifies an expansion of the NCS protocol to emulate an Access Node of an ETSI compliant local exchange. This annex specifies the mapping of expansion of the NCS protocol to V5.2.

Annex F of the present document specifies optional NCS components for the delivery of metering pulses.

This multi-part deliverable specifies IPCablecom, a set of protocols and associated element functional requirements. These have been developed to deliver high Quality of Service (QoS), enhanced secure IP multimedia time critical communication services to a consumer's home over a cable television Hybrid Fibre/Coaxial (HFC) data network.

NOTE 1: IPCablecom defines a set of documents in the framework of a network superstructure that overlays the two-way data-ready cable television network, e.g. as specified within ES 201 488 [5] and ES 200 800 [3]. While the initial service offerings in the IPCablecom product line are anticipated to be Packet Voice and Packet Video, the long-term project vision encompasses a large family of packet-based services. This may require in the future, not only careful maintenance control but also an extension of the present set of documents.

NOTE 2: The present set of documents aims for global acceptance and applicability. It is therefore developed in alignment with standards either already existing or under development in other regions and in International Telecommunications Union (ITU).

NOTE 3: There may also be relevant equivalent studies on-going in IETF or ITU specific to the needs of European IPCablecom. Where possible ETSI TC AT-D working group for IPCablecom should align annex B package annex or similar packages addressing the specific needs of European IPCablecom with work on going in IETF, Cablelabs, or the ITU.