Survivable routing in IP-over-WDM networks: An efficient and scalable local search algorithm

Abstract

In IP-over-WDM networks, a logical IP network is routed on top of a physical optical fiber network. An important challenge hereby is to make the routing survivable. We call a routing survivable if the connectivity of the logical network is guaranteed in case of a failure in the physical network. In this paper we describe FastSurv, a local search algorithm for survivable routing. The algorithm works in an iterative manner: after each iteration it learns more about the structure of the logical graph and in the next iteration it uses this information to improve its solution. The algorithm can take link capacity constraints into account and can be extended to deal with multiple simultaneous link failures and node failures. In a large series of tests we compare FastSurv with current state-of-the-art algorithms for this problem. We show that it can provide better solutions in much shorter time, and that it is more scalable with respect to the number of nodes, both in terms of solution quality and run time.

Algorithms for Failure Protection in Large IP-over-fiber and Wireless Ad Hoc Networks

“…In this paper we describe two recent algorithms solving the survivable mapping problem: SMART [22,23] and FastSurv [24,25,26]. These algorithms are very efficient, and somewhat complementary.…”

“…Each iteration of FastSurv consists of an evaluation and a number of logical link reroutings. Rerouting a single logical link has a complexity O(Dijkstra) (which is maximally of O(N 2 )) and the evaluation of survivability has a maximal complexity of O(N 4 ) [26]. Therefore, given that the maximum number of logical links to be rerouted in one iteration is the total number of logical links, which is O(N ) (we follow [17], where logical networks of a fixed degree are considered), a single iteration of FastSurv has a maximal complexity of O(N 4 ).…”

“…In a large series of tests, we have shown that the extended FastSurv algorithm outperforms tabu search in terms of solution quality and time [26]. Moreover, it is much more scalable.…”