NPP: A Facility Based Computation Framework for Restoration Routing Using Aggregate Link Usage Information

We present NPP – a new framework for online routing of bandwidth guaranteed paths with local restoration. NPP relies on the propagation of only aggregate link usage information [2,9] through routing protocols. The key advantage of NPP is that it delivers the bandwidth sharing performance achieved by propagating complete per path link usage information [9], while incurring significantly reduced routing protocol overhead. We specify precise implementation models for the restoration routing frameworks presented in [1] and [2] and compare their traffic placement characteristics with those of NPP. Simulation results show that NPP performs significantly better in terms of number of LSPs accepted and total bandwidth placed on the network. For 1000 randomly selected LSP requests on a 20-node homogenous ISP network [8], NPP accepts 775 requests on average compared to 573 requests accepted by the framework of [2] and 693 requests accepted by the framework of [1]. Experiments with different sets of LSP requests and on other networks indicate that NPP results in similar performance gains.