Online routing of bandwidth guaranteed paths with local restoration using optimized aggregate usage information

We investigate the problem of distributed online routing of bandwidth guaranteed paths with local restoration. A unified model is proposed that captures the bandwidth sharing characteristic of backup paths that provision local restoration, corresponding to different fault models. We apply the model to describe bandwidth sharing on backup paths for varying degrees of network state information. The extent of backup bandwidth sharing depends on the amount of network state information made available through routing protocols. A key design criterion for traffic engineering schemes is to maximize the sharing between backup paths, while minimizing this protocol overhead. M.S. Kodialam and T.V. Lakshman (see Proc. Infocom, p.376-85, 2001) demonstrated that propagating a constant amount of aggregated information per link leads to cost effective bandwidth sharing. We propose oAIS, a new aggregate information scenario, in which we judiciously select the propagated information, such that the protocol overhead is identical to that of Kodialam and Lakshman. Simulations show that oAIS outperforms other information scenarios with comparable protocol overheads.