Dynamic Light-path Configuration with GMPLS for WDM Networks
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Recently, wavelength division multiplexing (WDM) networks that multiplex wavelengths into a single optical fiber are attractive as an integral part of the infrastructure in the next generation Internet. In WDM networks, the routing in optical domain is feasible by establishing a lightpath between nodes. In WDM networks, core devices at nodes are optical crossconnect (OXC) and optical add/drop multiplexer (OADM). Generalized multiprotocol label switching (GMPLS), which is expected to support the Internet over WDM network, has been developed for OXC and not applied to OADM yet. In this paper, we apply GMPLS to the WDM network where nodes consist of OADMs, and propose a dynamic lightpath configuration method where lightpaths are dynamically established and released. The proposed method establishes lightpaths according to the congestion state of a node and releases when there are no packets to be transmitted in the node. We evaluate performances of the proposed method for tandem and ring networks by queueing analysis and simulation. Numerical examples show that for tandem networks, our method is efficient for the scalability of networks in comparison with static lightpath configuration. For ring networks, we show how the wavelength establishment/release time and holding time of a lightpath affect performance measures.