Segment routing as a basis for software defined network

Abstract

In this article the structure, main components and functioning of Segment Routing (SR) are analyzed. Segment routing is a WAN traffic routing technique existing on MPLS and only-BGP networks. Segment routing is also considered as a way of improving the infrastructure performance and efficiency. The main advantages of SR are achieved through the implementation of the SDN concept approach, without changing the standard data transferring plane for each of the technologies, above which SR can be applied. The article also covers the main areas of SR technology application, interaction in a centralized and decentralized network. The article provides the examples of controllers for SDN implementation using SR. The presence of a controller in the network permits the realization of bandwidth on demand, traffic prioritize, selection of the most suitable route in the network for different types of traffic easier and more often without any protocols or devices. Another important advantage of controller’s implementation on networks using SR can be a reduction of the services recovery time after a failure, because the route will be rebuilt faster (compared to MPLS). SR can be considered as an opportunity to refuse from such protocols as LDP or RSVP for situation when used on a network in tandem with a controller. IPv6 networks, using SR, are able to acquire additional capabilities in programmability and flexibility.