Enhanced multi-layer protection in multi-service GMPLS networks

Abstract

Abstract-This paper focuses on QoS routing with protection in an MPLS network over an optical layer. In this multi-layer scenario each layer deploys its own fault management methods. A partially protected optical layer is proposed and the rest of the network is protected at the MPLS layer. New protection schemes that avoid protection duplications are proposed. Moreover, this paper also introduces a new traffic classification based on the level of reliability. The failure impact is evaluated in terms of recovery time depending on the traffic class. The proposed schemes also include a novel variation of minimum interference routing and shared segment backup computation. A complete set of experiments proves that the proposed schemes are more efficient as compared to the previous ones, in terms of resources used to protect the network, failure impact and the request rejection ratio.

An Adaptive Segment Repair in MPLS Protection

“…Previous MPLS protection researches only consider one or two QoS parameters, such as resource utilization [4][5][6][7][8], packet loss [4,[6][7], recovery time [5][6]9] and request rejection ratio [10][11]. However, all QoS requirements and other aspect, like failure probability [8] are not considered at the same time.…”

“…Recently, much effort has been concentrated on the designing of Multi-Protocol Label Switching (MPLS) [1] protection method [2][3][4][5][6][7][8][9][10][11]. Three main approaches exist [2]: Global Repair, Local Repair and Segment Repair.…”

Incorporating Protection Mechanisms in the Dynamic Multi-layer Routing Schemes

“…Two network scenarios may be considered in order to improve network management and resources: 1) the static multi-layer network scenario or 2) the dynamic multi-layer network scenario. In the static multi-layer network scenario [9,10], the logical topology defined by the optical layer is given, fixed and partially protected. Some of the logical links are assumed to be already protected at the optical layer.…”

The Effects of Multi-Layer Traffic on the Survivability of IP-Over-WDM Networks

“…1. A degree-4 top network can be accomplished by adding links (1,5), (2,6), and (3, 6) to the degree-3 network. A degree-5 top-layer network is set through its full mesh, i.e., adding links (1, 6), (2,5), and (3, 4) to the degree-4 network.…”

“…Owning to fast failure detection and pre-reserved resources in WDM networks, recovery at this layer is usually faster [6]; however, it may not be able to provide survivability when failures happen at the top layer. In some cases, this strategy is not aware of the IP top-layer node failures unless there is an appropriate signalling coordination like GMPLS.…”