scope:

Introduction and Purpose

The present document defines extensions to the IPCablecom Network-based Call Signalling (NCS) [2] protocol to support the following analogue trunking for PBX interfaces on an embedded Voice-Over-IP client device in a IPCablecom environment:

• Ground-start lines.

• PBX one-way and two-way DTMF (dual-tone multi frequency tones) trunks.

As shown in figure 1, the IPCablecom NCS specification [2] already defines the Loop-Start line interface typically used for residential services today. The present document is designed for additional line/trunk interfaces to support analogue trunking for PBX so that the MTA (multimedia terminal adapter) may be used to interface directly to a Legacy PBX via a Ground-Start line or other trunk interface (E&M - E and M Signalling or DID - Direct Inward Dialling). Example PBX trunk interfaces are shown below.