The paper studies the application of fuzzy set optimization techniques for the reconfiguration of optical internets using Internet Protocol (IP) over Wavelength Division Multiplexed (WDM) (IP-over-WDM) technology. The IP-over-WDM networking technology with terabits per second bandwidth become a natural choice for the future generation internet networks (optical internets), Wide Area Network (WAN) environments and backbone networks due to its potential ability to meet the rising demand of high bandwidth and low latency communication. Recently, Virtual Topology Reconfiguration (VTR) of IP-over-WDM networks has received greater attention among researchers. Fuzzy set finds many applications in the field of network engineering, which includes linear programing, traffic prediction, network modeling, traffic modeling, etc. In this paper, we have presented a new approach for reconfiguring virtual topology of IP-over-WDM networks using fuzzy set optimization technique. The computed results show that this new approach achieves better performance in terms of computational accuracy, number of changes and Average Weighted Hop Count (AWHT).

In the last decade, Wavelength Division Multiplexed (WDM) optical fiber networking technologies brought a revolution in high-speed communication networks which are now able to meet the high bandwidth demands of current voice and data traffic. All optical WDM networks using wavelength routing are considered to be potential candidates for the next generation of wide area backbone networks. The demand for bandwidth is growing at a rapid pace and the Internet data traffic is expected to dominate voice traffic in the near future. With the IP playing a dominant role in wide area networking technology and advancements in wavelength routed WDM technology to provide enormous bandwidth, the IP-over-WDM networks (Mukherjee et al., 1996) become the right choice for the next generation internet networks. The IP-over-WDM network consists of a set of WDM links and nodes, each of which consists of an electronic IP router part and an Optical Cross Connect (OXC) part.

The physical topology (Rajesh and Kumar, 2001) consists of optical WDM routers interconnected by point-to-point fiber links and nodes in an arbitrary topology. In these types of networks, data transfer is carried on from one node to another node using lightpaths. A lightpath (Ramaswami and Sivarajan, 1996) is an all-optical path established between two nodes in the network by allocating same wavelength on all links of the path. In IP-over-WDM networks, lightpaths are established between IP routers.

A virtual topology (Dutta and Rouskas, 1999) is a set of pre-established lightpaths established to provide all optical connectivity between nodes for a given traffic demand. The virtual topology is established logically through lightpaths, each identified by an independent wavelength which provides end-to-end connectivity for transmission over the optical medium. The embedding of virtual topology over a physical topology results in minimizing the number of nodes that were actively involved in network transmission. The virtual topology is a graph with nodes as routers in the physical network topology and edges corresponding to the lightpaths between them. A virtual topology is designed with an objective of minimizing certain objective function such as the Average Weighted Hop Count (AWHT) of the virtual topology congestion.

Telecommunications Journal, Fuzzy Set Optimization Technique, Virtual Topology Reconfiguration, Optical Fiber Networking Technologies, Network Transmission, Virtual Topology Congestion, Optical Network Connectivity, Network Modeling, Genetic Algorithm, Linear Programing Methods, Wireless Optical Network, Fuzzy Set Multi Objective Linear Programming.