Dynamic routing with inaccurate link state information in integrated IP-over-WDM networks

• Published in: Computer networks (Amsterdam, Netherlands : 1999) Netherlands : 1999), 2004-12, Vol.46 (6), p.829-851
• Main Authors: Li, J., Mohan, G., Tien, E. Cheng, Chua, K.C.
• Format: Article
• Language: English
• Subjects: Access methods and protocols, osi model; Algorithms; Applied sciences; Bandwidths; Communications networks; Exact sciences and technology; GMPLS; Integrated routing; Internet; Internet Protocol; IP-over-WDM; Operation, maintenance, reliability; QoS routing; Quality of service; Routing; Studies; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Telephony; Teleprocessing networks. Isdn; Transmission and modulation (techniques and equipments); Uncertainty; Uncertainty modeling; Voice over Internet protocol; Wave division multiplexing; Wavelength division multiplexing
• ISSN: 1389-1286; 1872-7069
• DOI: 10.1016/j.comnet.2004.06.022

In this paper, we investigate the problem of dynamically routing bandwidth-guaranteed label switched paths (LSPs) in integrated IP-over- wavelength division multiplexed (WDM) networks with inaccurate link state information. To select a good path, a routing algorithm needs up-to-date link state information. This leads to excessive update overhead and scalability problems. In real networks, from the practical point of view, in order to avoid extensive overhead of advertising and processing link state information, updates need to be made periodically or based on a threshold trigger. This leads to inaccuracies in the link state information. Our contribution is that we consider the routing problem taking into consideration the uncertainty of link state parameters due to wavelength inaccuracy in addition to bandwidth inaccuracy. Based on the threshold-triggered update scheme, we present a probabilistic method to model the uncertainty of link state parameters. We then define a cost function reflecting the uncertainty. Depending on different cost metrics chosen to be optimized, we propose two routing algorithms considering the uncertainty of link state parameters. The objective is to minimize the impact of inaccurate information so that the blocking probability as well as setup failures are reduced. We use various performance metrics such as total blocking probability, blocking probability due to setup failures, blocking probability due to routing failures, bandwidth update frequency, and wavelength update frequency to evaluate the effectiveness of the proposed algorithms. Through extensive simulation experiments, we show that our algorithms can significantly reduce the impact of inaccurate link state information and perform very well.