Evaluation of the APS protocol for SDH rings reconfiguration

Abstract

architecture is one of the underlying technologies used by ATM networks. The SDH includes various protection mechanisms. One main design issue is probably the recon guration process in case of failure. In case of SDH works on optical bres with a ring network topology, the Automatic Protection Switching (APS) protocol can be used. This paper addresses the problem of maximum allowed recovery time in four bers ring architecture. We analyze the APS protocol and derive upper bounds for the processing time in each node of the network in order to cope with the maximum recon guration time of 50 ms, as speci ed in the standard. We nally analyze the behavior of the system in case of two interleaved failures. A worst case analysis is carried out, showing that a 100 ms recon guration time can be guaranteed.

Migration of optical core network to next generation networks – Carrier Grade Ethernet Optical Transport Network

“…In contrast, thousands of users often have connection via one end router which is the most sensitive part of network. In that case, instead of additional routers and links, pairs of panel control processors are used, duplicate liner board are used or Tandem links are used (such as SDH APS -Synchronous Digital Hierarchy Automatic Protection Switch) to provide tolerance [1], [2].…”

Design and analysis of optical metropolitan networks

“…Switching (APS)[14][15][16][17][18][19][20][43][44][45][46][47] and comes in two flavors: Unidirectional Path-Switched Ring (UPSR) and Bidirectional Link-Switched Ring (BLSR).UPSR is the simpler of the two. A sending node injects identical traffic in both fibers of the dual counter-rotating ring.…”