Multi-layer MPLS network design: The impact of statistical multiplexing

摘要: The possibility of adding multi protocol label switching (MPLS) support to transport networks is considered an important opportunity by telecom carriers that want add packet services and applications their networks. However, the question arises whether it suitable have MPLS nodes just at edge network collect traffic from users, or introduce also facilities on a subset core in order exploit flexibility multiplexing, thus inducing better bandwidth allocation. In this paper, we propose mathematical programming model for design two-layer where top (SDH WDM depending required link speed). Our models take into account tradeoff between cost savings allocation due statistical multiplexing grooming effects induced nodes. matrix specifies each point-to-point request pair values: mean value additional one. Using model, effect allows allocate capacity equal sum all values demands routed only highest We path-based Mixed Integer Programming (MIP) problem optimizing number location capacities. apply Lagrangian relaxation use subgradient method obtain lower bound cost. As path variables used routing grows exponentially with graph size, initially limited column generation approach. heuristic approach get good feasible solution. Computational results are reported small size real-world instances.