Investigation of FlexAlgo for User-driven Path Control

TL;DR

This paper investigates FlexAlgo as a framework for user-driven path control within intra-domain SR networks. It develops and tests a FlexAlgo-based solution and an automated Path Controller to let users specify metrics and constraints, aiming to increase security and trust in routing. The experiments demonstrate FlexAlgo's capability to steer traffic via user-defined policies across IGP/TE metrics, adapt to dynamic conditions, and support automated deployment through NETCONF/YANG tooling. While the results validate feasibility in a controlled, SR-MPLS environment, limitations include the virtualization platform's lack of real-time delay measurement and incomplete TE-metric integration, guiding future work toward broader topologies and SRv6/IS-IS deployments.

Abstract

This paper examines the Flexible Algorithm (FlexAlgo) for its potential to enable user-driven path control in intra-domain Segment Routing (SR) enabled networks. FlexAlgo is a relatively new approach to intra-domain routing that allows multiple custom algorithms to coexist within a single domain. This capability has the potential to provide users with greater control over the paths their data takes through a network. The research includes a thorough investigation of the FlexAlgo approach, including an examination of its underlying techniques, as well as a practical implementation of a FlexAlgo-based solution. We depict performed experiments where we implemented FlexAlgo in three different scenarios. We also present how we developed an automated tool for users to control traffic steering using preferred metrics and constraints. The results of this investigation demonstrate the capabilities of FlexAlgo as a means of enabling user-driven path control and therefore increase security and trust of users towards the network.

Figures (3)

• Figure 1: Network topology created in Cisco Modelling Labs.
• Figure 2: Path chosen for FlexAlgo 128
• Figure 3: Path chosen for FlexAlgo 131