Compact and non-compact formulations for segment routing

Abstract

Segment routing allows flexible control of packet routing using a segment list. A segment list consists of node-segments that utilize equal-cost multiple paths and adjacency-segments that directly use available links between source and destination nodes. This characteristic of segment routing makes it a good candidate for simplified and scalable traffic engineering. This thesis aims to minimize maximum link utilization (congestion) and processing energy costs simultaneously. In the thesis, a segment-based compact model and a path-based column generation model are developed. Initially, the models are utilized with maximum link utilization as the sole objective; both the compact model and the column generation model outperform existing methods in the literature, with the column generation approach excelling in its ability to solve large-scale and complex instances. Then, a multi-objective framework is tested for various parameter configurations that influence the energy consumption and congestion. The experiments over realistic network instances show potential for exploiting the energy-congestion trade-off for energy savings with minimal impact on congestion.