A heuristic approach to assess the traffic matrix of an ISP exploiting segment routing flexibility

The Ingress Egress Traffic Matrix (IE TM) assessment is a fundamental step of the network management for an ISP network, since it represents the key input parameter used by any Traffic Engineering solution to optimize the resource utilization and to improve the Quality of Service. The actual TM assessment procedures are based on estimation algorithms or measurement based approaches. This paper presents a method to measure the intensity of traffic flows, that overcomes the limits of the classical measurement/estimation based approaches. The idea is to exploit the flexibility of the Segment Routing paradigm to implement controlled routing changes so that to measure the intensity of a subset of network flows. The main contribution of the work is to show the feasibility of the proposed approach by means of a low complexity heuristic, referred to as Path Cost Bases (PaCoB), able to identify the list of routing changes that allow to improve the TM assessment procedure. The heuristic is composed of successive steps, referred to as snapshots: in each snapshot the routing of a set of flows is changed so that to assess their intensities. The performance evaluation show thatPaCoB assesses the intensity of more than 90% of flows. Moreover, when used in conjunction with an estimation algorithm, PaCoB allows to reduce the estimation error by more than 50% performing only 10 snapshots.