ZTE Corporation ZTE Corporation China Mobile KDDI Corporation This document specifies extensions to the Inter-Chassis Communication Protocol (ICCP) to support inter-chassis linear multiplex section protection (MSP) as described in G.841 and automatic protection switching as defined in ANSI T1.105.01. This document considers an application where a CE device or access network is attached to two PEs through Synchronous Digital Hierarchy (SDH) circuits, and MSP or APS is used to protect the attachment circuits. ICCP is used to support configuration and state synchronization between two chassis. CE device or access network attached to more than two PEs is out of the scope of this document.