IETF RFC 5718 PDF

The Generic Associated Channel (G-ACh) has been defined as a generalization of the pseudowire (PW) associated control channel to enable the realization of a control/communication channel that is associated with Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs), MPLS PWs, MPLS LSP segments, and MPLS sections between adjacent MPLS-capable devices.

The MPLS Transport Profile (MPLS-TP) is a profile of the MPLS architecture that identifies elements of the MPLS toolkit that may be combined to build a carrier-grade packet transport network based on MPLS packet switching technology.

This document describes how the G-ACh may be used to provide the infrastructure that forms part of the Management Communication Network (MCN) and a Signaling Communication Network (SCN). Collectively, the MCN and SCN may be referred to as the Data Communication Network (DCN). This document explains how MCN and SCN messages are encapsulated, carried on the G-ACh, and demultiplexed for delivery to the management or signaling/routing control plane components on an MPLS-TP node.