Abstract:
Internet service providers and enterprise networks face rapid changes and rapid growth of the internet, and the networks become complex in operations to support the strict Service-level Agreements (SLAs) needed applications. Segment Routing (SR) is a source routing technology that overcomes the conventional Multiprotocol Label Switching (MPLS) networks’ drawbacks in scalability, flexibility, and applicability in Software-defined Networking (SDN). SR enables the source device to instruct the path using a segment or list of segments to go through the network. SR can be implemented in IPv6 and MPLS. A segment can be defined as information that instructs SR capable nodes to execute on the incoming packet. In SR, the packet header has enough instruction for packets to traverse from source to destination. So, SR does not need separate signaling protocols and does not maintain the path state in the intermediate routers.
As the default forwarding of SR, equal-cost multi-path (ECMP), can cause higher maximum utilization of links in the network, ECMP is avoided, and strict SR paths are used. This thesis studies ILP models in the paper [1] to evaluate traffic engineering performance in SR networks and enhance the integer linear programming (ILP) model, which forces to choose among only shortest paths to reduce the maximum utilization. This thesis compares the results of the ILP models of [1] and the proposed enhanced version. Results show that we can achieve the maximum utilization as nearly as the proposed model of [1]. As the Segment List Depth (SLD) to be appended to form a strict SR-TE path introduces the packet overhead, we also reduce the number of SLD to be appended. Finally, we will develop an application to implement our proposed enhanced ILP model in an emulated environment using commercial routers, SDN controller, and Postman.
