Optimal LSP capacity and flow assignment using traffic engineering in MPLS networks

Quality of service (QoS) and traffic engineering (TE) capabilities are two important criteria in today's networks for supporting real-time applications. Multiprotocol label switching (MPLS) plays a key role in IP networks by providing QoS and TE features. In this paper, we first propose an analytical label switched path (LSP) model associated with the TE issue that assumes two different LSP transmission mechanisms: layer 2 cut-through switching and layer 3 default routing. Secondly, we propose a new LSP traffic flow distribution optimization objective function to minimize the overall network transmission delay. The simulation results show that the proposed model minimizes the overall delay and distributes the traffic on each link evenly. In other words, the connection-oriented forwarding characteristics of layer 2 switching technology are achieved in the proposed model and the incorporated objective function while retaining the equally desirable flexibility and scalability of layer 3 routing.