Optimal capacity placement for path restoration in STM or ATM mesh-survivable networks

Abstract

Abstract-The total transmission capacity required by a transport network to satisfy demand and protect it from failures contributes significantly to its cost, especially in long-haul networks. Previously, the spare capacity of a network with a given set of working span sizes has been optimized to facilitate span restoration [11], [12]. Path restorable networks can, however, be even more efficient by defining the restoration problem from an end to end rerouting viewpoint. We provide a method for capacity optimization of path-restorable networks which is applicable to both synchronous transfer mode (STM) and asynchronous transfer mode (ATM) virtual path (VP)-based restoration. Lower bounds on spare capacity requirements in span-and path-restorable networks are first compared, followed by an integer program formulation based on flow constraints which solves the spare and/or working capacity placement problem in either spanor path-restorable networks. The benefits of path and span restoration, and of jointly optimizing working path routing and spare capacity placement, are then analyzed.

Spare Capacity Planning for Survivable Mesh Networks

“…In contrast, for path restoration, the source destination node pairs whose traffic traversed the failed device are responsible for restoration and reroute over the entire path set between each affected source destination pair. In general, path restoration is known to require less spare capacity than link restoration [1,[3][4][5][6]. However, path restoration is more complex to implement as many more nodes are involved in the restoration process.…”

“…Several highly publicized outages have illustrated that disruption of communication services is very costly to businesses, governments and the general public. This has led to growing interest in the design of networks which are survivable [1][2][3][4][5][6][7][8][9][10][11].…”

“…Previous research on spare capacity assignment in STM mesh networks adopts the problem context above and uses either mathematical programming techniques [1][2][3][4][5][6][7]11] or heuristics [8][9][10][11] to determine the spare capacity allocation. In both cases, algorithms have been developed for link restoration and path restoration.…”

“…A typical goal is to determine the spare capacity placement such that all normal traffic can be restored for any single link failure in the network. Mathematical programming methods have been used to formulate the spare capacity planning problem for link and path restoration approaches as Integer Programming (IP) models [2][3][4][5][6]11]. The objective function adopted is to minimize the spare capacity required for achieving restoration from a specific failure condition.…”

Analysis and algorithms for partial protection in mesh networks

“…There are a variety of protection strategies available [3], [4], [5]. The most common in backbone networks today is guaranteed path protection [6], which provides an edge-disjoint backup path for each working path, resulting in 100% service restoration after any link failure.…”