Failure Resilient Traffic Engineering Using Segment Routing

Traffic engineering is an important concept that allows Internet Service Providers (ISPs) to utilize their existing routing hardware more efficiently. One technology that can be used in this field is Segment Routing (SR). While transferring SR approaches from theory towards an actual deployment, it quickly becomes apparent that there are many requirements and constraints that have to be satisfied. One of the most important requirement for a traffic engineering approach is the resilience against failure scenarios. In this paper, we propose a post-convergence aware 2-SR based optimization model. With it, we are able to proactively find a single SR configuration that is beneficial in all predefined failure scenarios, including single link failures, shared risk link group failures, and node failures. We evaluate our model with recently measured data from a tier 1 ISP and show that we can improve over state of the art routing approaches.