An evaluation of Flex-Algo traffic engineering techniques in Segment-Routing networks

Flexible Algorithm (Flex-Algo) is an emerging traffic engineering solution under standardization for IP Segment-Routing based networks, targeted to address the burgeoning requirements for enhanced Quality of Service (QoS) through dynamic and intelligent routing optimizations. This paper explores the potential of Flex-Algo in adapting QoS-based traffic profiles, while minimizing network latency and optimizing resource allocation across in heterogeneous network scenarios. In this context, we propose an operational set up where two IP topologies with different IGP weights are used for latency-constrained and not-latency constrained traffic, in two different flex-algos. We compare this with baseline setups with one flex-algo, tuned for minimizing latency or for minimizing number of IP hops. We apply this to the dimensioning of three networks. Results show how flex-algo permits reducing network costs while meeting latency constraints, by providing lower latency paths only to those flows requiring it.