SDN Architecture and Southbound APIs for IPv6 Segment Routing Enabled Wide Area Networks

TL;DR

This paper explores integrating SDN with IPv6 Segment Routing (SRv6) in wide area networks, presenting architecture, API designs, an emulation system, and performance evaluations to enhance scalability and manageability.

Contribution

It introduces a comprehensive SDN architecture for SRv6 networks, including multiple Southbound API implementations and an emulation system for testing and development.

Findings

API implementations vary in performance and complexity

Configuration updates impact SRv6 node performance

The architecture supports scalable and manageable IPv6 networks

Abstract

The SRv6 architecture (Segment Routing based on IPv6 data plane) is a promising solution to support services like Traffic Engineering, Service Function Chaining and Virtual Private Networks in IPv6 backbones and datacenters. The SRv6 architecture has interesting scalability properties as it reduces the amount of state information that needs to be configured in the nodes to support the network services. In this paper, we describe the advantages of complementing the SRv6 technology with an SDN based approach in backbone networks. We discuss the architecture of a SRv6 enabled network based on Linux nodes. In addition, we present the design and implementation of the Southbound API between the SDN controller and the SRv6 device. We have defined a data-model and four different implementations of the API, respectively based on gRPC, REST, NETCONF and remote Command Line Interface (CLI). Since it is important to support both the development and testing aspects we have realized an Intent based emulation system to build realistic and reproducible experiments. This collection of tools automate most of the configuration aspects relieving the experimenter from a significant effort. Finally, we have realized an evaluation of some performance aspects of our architecture and of the different variants of the Southbound APIs and we have analyzed the effects of the configuration updates in the SRv6 enabled nodes.