IEC 62439-2 Ed. 1.0 b:2010

Industrial communication networks - High availability automation networks - Part 2: Media Redundancy Protocol (MRP)

IEC 62439-2:2010 is applicable to high-availability automation networks based on the ISO/IEC 8802-3 (IEEE 802.3) (Ethernet) technology. It specifies a recovery protocol based on a ring topology, designed to react deterministically on a single failure of an inter-switch link or switch in the network, under the control of a dedicated media redundancy manager node. It cancels and replaces IEC 62439 published in 2008 and constitutes a technical revision. It includes the following significant technical changes with respect to IEC 62439 (2008):
 - adding a calculation method for RSTP (rapid spanning tree protocol, IEEE 802.1Q),
 - adding two new redundancy protocols: HSR (High-availability Seamless Redundancy) and DRP (Distributed Redundancy Protocol),
 - moving former Clauses 1 to 4 (introduction, definitions, general aspects) and the Annexes (taxonomy, availability calculation) to IEC 62439-1, which serves now as a base for the other documents,
 - moving Clause 5 (MRP) to IEC 62439-2 with minor editorial changes,
 - moving Clause 6 (PRP) was to IEC 62439-3 with minor editorial changes,
 - moving Clause 7 (CRP) was to IEC 62439-4 with minor editorial changes, and
 - moving Clause 8 (BRP) was to IEC 62439-5 with minor editorial changes,
 - adding a method to calculate the maximum recovery time of RSTP in a restricted configuration (ring) to IEC 62439-1 as Clause 8,
 - adding specifications of the HSR (High-availability Seamless Redundancy) protocol, which shares the principles of PRP to IEC 62439-3 as Clause 5, and
 - introducing the DRP protocol as IEC 62439-6.   

This publication is to be read in conjunction with IEC 62439-1:2010.