Metro/core routing information exchange in optical networks

Next generation optical network technology has attracted lots of attention from both academia and industry. Large optical networks are typically partitioned into metro and core sub-networks due to the different service and technology requirements. A client optical connection may pass through multiple sub-networks, originating in a metro sub-network, traversing the core network, and accessing the destination on a different metro network. This structure is similar to current ISP networks, which may be divided into multiple routing areas for scalability. However, optical networks are different from IP networks. The difference affects the routing information that needs to be exchanged in metro/core optical networks such that IP routing protocols require significant extensions if they are to be applied in optical networks. In this paper, we focus on Metro/Core routing requirements and present a proposal to extend the current IP multi-area Open Shortest Path First (OSPF) protocol to exchange routing information over metro/core sub-network interfaces. A brief discussion of our prototype implementation is given at the end of this paper.