A lightweight deployment of TD routing based on SD-WANs

Multipath routing conforms to the evolution principle of network development and is a trend of routing architectures. It can not only meet the needs but also enhance the performance and security of a network. However, deploying multipath routing further increases the scale of the forwarding information base (FIB) and the cost of forwarding devices. Therefore, to realize the lightweight deployment of multipath routing with a distributed architecture, this paper takes two-dimensional routing (TD routing) as an example to provide a solution. We propose a distributed storage mechanism of TD routing in combination with SRv6 (TDSR) and the corresponding SRv6 header (SRH) compression (CARD) method. The main methods are as follows: Inspired by a software-defined wide area network (SD-WAN), this paper introduces segment routing (SR) in the data plane, which can disperse TD-FIBs in different ingress nodes. The ingress routers push path information into the stack, and the intermediate routers forward the packets according to the SRH. Second, for the bandwidth waste of the SRH, compression is attempted by comparing the difference between the the shortest path first (SPF) path and the SRv6 path. Only a few hops in the TD path that are different from those in the one-dimensional (OD) path are kept. Finally, we sort out several typical application scenes of multipath routing and discuss several simplification algorithms. The experimental results show that the TDSR can reduce TD entries by 69%, and the average compression rate of CARD can reach 70%. In addition, CARD can be combined with existing methods to improve their effect.