This document specifies an Inter-Chassis Communication Protocol
(ICCP) that enables Provider Edge (PE) device redundancy for Virtual
Private Wire Service (VPWS) and Virtual Private LAN Service (VPLS)
applications. The protocol runs within a set of two or more PEs,
forming a Redundancy Group, for the purpose of synchronizing data
among the systems. It accommodates multi-chassis attachment circuit
redundancy mechanisms as well as pseudowire redundancy mechanisms.