Study on routing algorithms of multi-priority label switch path in MPLS over WDM mesh networks

An extended layered graph of MPLS over WDM mesh networks is designed in this paper, which overcomes the shortcomings of original layered graph and involves the limited optical transceivers at routing nodes. Based on different QoS constraint, the priority of label switch paths is classified and the corresponding routing algorithm DIRA (Differentiating Integrated Routing Algorithm) is proposed and studied. The LSP's QoS and optimized network resources utilization are taken into account comprehensively in DIRA. The comparison of DIRA with the representative optical routing algorithms via simulation shows that it can reduce the blocking probability of delay-constraint LSP and improve the network throughput.