Survivability-Enhancing Routing Scheme for Multi-Domain Networks

We present a routing solution which eliminates the inherent path exploration problem of BGP and thereby enhances survivability in multi-domain networks. The path exploration problem is caused by the dependency among paths learned from neighboring domains. We propose to solve this issue by using two domain level disjoint paths. Our work is based on the aggregated representation of transit domains. The aggregated scheme we use is obtaining the shortest path between each pair of border routers for the associated domain. We also propose to use a single node to represent the destination domain, thereby the size of routing table is 2*(n-1). To implement our solution, domain level source routing is used and a SDRP header is added to the delivered packet. This avoids re-calculation and path exploration when repairing inter-domain link failures. Inter-domain link failures must be repaired at domain level, while intra-domain link failures can be repaired by neighboring nodes, border routers or at domain level. The intra-domain repair methods are compared by simulation and based on the results border router repairing is recommended.