Traffic Engineering with Segment Routing Considering Probabilistic Failures

Segment Routing (SR) is a source routing paradigm that routes a packet through an ordered list of instructions called segments. It is widely used in Traffic Engineering (TE) because of its simplicity and scalability. Although there are lots of research about TE with SR (SR-TE), fewer consider network failures. The reactive approaches may suffer from latency and update issues, and the proactive approaches don't perform very well because the objectives aren't carefully designed. Besides, although different types of failures are considered, the failure probabilities are ignored. In this paper, we take failure probabilities in to consideration, and propose a proactive 2-SR model 2SRPF to handle SR-TE problem with network failures, aiming at minimizing maximum link utilization (MLU). Considering that severe failures are more noteworthy, we use probability as a severity threshold, and minimize the expectation of the larger MLUs whose corresponding failure states have probabilities sum to a specific threshold value. We solve it with probabilistic risk management. Experiments show that 2SRPF performs well with one threshold setting for different topologies consistently, and gets close to optimal results when network fails.