Retransmission in OBS networks with fiber delay lines

While most transmission schemes in OBS networks relegate retransmission to higher protocol layers, the scheme proposed in this paper reduces retransmission delays by exploiting fiber delay lines at the optical layer. We present an analysis of the scheme that focuses not only on individual components but also on the end-to-end properties of the network. We also propose a facility location model suitable for optimizing the locations of sites with fiber delay lines when the number of such sites is limited. Evaluation of our proposed scheme on a common test network shows that major improvements in performance are possible.