Disjoint-Path Segment Routing: Network Reliability Perspective

Achieving five-nines reliability in communication networks is of paramount importance to network operators. Adopting multipath Segment Routing (SR) in networking offers several key advantages in load balancing, optimal link utilization, reducing congestion, and enhancing reliability. Equal-cost multipath (ECMP) routing falls short to effectively utilize a multipath approach because ECMP may still forward traffic through the specific paths resulting in decreased network reliability. In this paper, we propose a novel two-phase Disjoint-path SR-based reliability framework to enhance the current network reliability. This framework drives network traffic flows through disjoint paths, resulting in effective load balancing and improving network reliability to meet stringent requirements of various services. Our proposed framework includes the following: a) Phase I: Optimization phase uses Mixed-Integer Linear Programming (MILP) formulation to find the optimal multipath that minimizes the maximum utilization of a given network while transmitting traffic between two terminal nodes, and b) Phase II: This phase splits the multipath of phase I into two disjoint multipaths, namely working and backup. The proposed framework is implemented, and its validation and effectiveness are demonstrated through simulation results.