IMSH: an iterative heuristic for SRLG diverse routing in WDM mesh networks

Abstract

Abstract-survivable routing of a connection involves computation of a pair of diverse routes such that at most one mute fails when failures occur in the network topology. A subset of links in the network that share the risk of failure at the same time are said to belong to a Shared Risk Link Gmup (SRLG) [3]. A network with shared risk link groups defined over its links is an SRLG network. A failure of an SRLG is equivalent to the failure of all the links in the SRLG. For a connection to he survivahle in an SRLG network its working and protection paths must he routed on SRLG diverse paths. SRLG diverse routing problem has been proved to he NP-complete in [l] According to the quality of service requirement of a survivable connection request, dedicated protection or shared protection can be used to establish the connection request.With dedicated protection, the connection is established on both the SRLG diverse working and protection paths. The simplest heuristic for computing SRLG diverse path pair is the two-step approach, hut it suffers from the trap topology problem. In [Z] an iterative heuristic (ITSH) using the two-step approach was proposed to compute least cost SRLG diverse path pair. Suurhalle's algorithm computes a pair of least cost linkdisjoint paths between a node pair. In this work we present a modified Suurhalle's heuristic for computing the SRLG diverse routes between a node pair. We then propose an iterative heuristic (IMSH) which uses the modified Suurballe's heuristic for computing the least cost SRLG diverse routes. We also present an 1/2-cost-improvement optimality check criterion for dedicated protection.

A survivable multicast routing mechanism in WDM optical networks

“…Despite of obtaining interesting results, authors of [1,[4][5][6][7][8][9] did not consider the differentiated reliability feature, allowing for statistical survivability and reliability guarantees.…”

“…A multitude of survivable routing mechanisms have been proposed for WDM optical networks with SRLG constraints [1][2][3][4][5][6][7][8][9]. In [1], Li et al proposed a greedy heuristic for multicast protection under SRLG constraints.…”

“…Their algorithm iteratively separates the network nodes into two sets and computes the working and backup paths respectively from each set. Todimala et al [7] also proposed an iterative heuristic for diverse routing under SRLG constraints that computes the least cost SRLG diverse paths pair.…”

p-Cycle Design in Survivable WDM Networks with Shared Risk Link Groups (SRLGs)

“…The NP-completeness proof of the SRLG-diverse routing problem as well as an ILP solution are given in [11], [12]. Heuristic approaches to this problem are proposed in [13], [14]. In this paper, we will discuss a new protection strategy for the single-SRLG failure model, that is, to apply p-cycle network design to networks with SRLGs.…”

A heuristic with bounded guarantee to compute diverse paths under shared protection in WDM mesh networks

“…In paper [11] a graph based approach is used to present an algorithm for computing SRLG-diverse paths, but it only works for SRLGs consisting of links incident on a single node. In [12] an iterative heuristic for computing SRLG-diverse paths for dedicated protection is proposed. Most of these existing heuristics only consider minimizing the sum of the costs of the SRLGdiverse paths i.e., computing SRLG-diverse paths for dedicated protection.…”