A Distributed Congestion Mitigation Mechanism Based on Neighboring Nodes Traffic Steering
Lirong Bai, Liang Zhang, Geng Zhang, Lin Zhang, Paolo Medagliani, Sébastien Martin · 2023
Congestion mitigation plays a vital role in network optimization to reduce the link load when unexpected events, such as link failures or traffic peaks, happen in the network. To solve this problem, we propose a distributed congestion mitigation (CM) mechanism to load balance traffic from a congested link to different alternative paths as soon as a router detects congestion over an outgoing interface. We present an efficient implementation of the proposed CM mechanism based on offline computation of alternative paths using a Neighbor Deviation Algorithm (NDA). The alternative paths are then encoded as Segment ID (SID) lists to be inserted into the Segment Routing Header (SRH) of the rerouted packets in the case a congestion happens. We benchmark our approach against a K-Shortest Path (KSP) algorithm, and we show, via a Python simulator, the advantage of using the CM mechanism into a real backbone network from China Mobile.