Traffic Engineering in multiprotocol label switching VPNs

Abstract

The changing nature of Internet-based applications is imposing stricter demands on the performance of the Internet. For many new applications requiring differentiated quality of service, the best effort model of the internet is no longer adequate. Multiprotocol label switching (MPLS) overlays a connection oriented network on the connection-less IP networks, thereby addressing several shortcomings of the IP network. MPLS improves the forwarding speed, and it provides a virtual path capability to efficiently carry differentiated services. Additionally, MPLS enables traffic engineering by explicit traffic engineering tunnels to be set up across the network to utilize all available bandwidth in an efficient manner. Constraint-based routing has been proposed as an effective approach to implement traffic engineering in MPLS. In this thesis, we propose several constraint-based routing algorithms to support both Quality of Service (QoS) and BE traffic of VPNs over the MPLS network. Our algorithms also show the explicit route setup for VPNs by including attributes like node affinity and link affinity constraints. We also study the path length limit for the QoS traffic of VPNs which may have stringent hop constraints due to delay requirements. Finally, we propose various path protection schemes for MPLS VPNs. Our approach for VPNs are scalable to large networks.