Impact of peer-to-peer traffic on the efficiency of optical packet rings

This paper addresses the impact of traffic profiles on the efficiency and performance of synchronous optical packet rings. Synchronous optical packet rings are developed to replace the currently deployed circuit based MAN architectures. The studied system differs from the well known resilient packet ring in the sense that optical packets are not electronically processed when transiting through nodes; on the other hand, a wavelength is used as a control channel and is used by the station to identify the packets to be extracted from the data channels. The performance of the optical packet ring is studied both analytically and by simulation. Simulations have been carried out by developing a new MAC model for the network simulator (ns-2) package. Analytical modeling is based on a simple Geo/Geo/1 queueing model, in which the parameters are computed to take account of different traffic scenarios under study. In particular, we model both client/server (CS) and peer to peer (P2P) traffic, which allows the analysis of the impact of traffic profiles on the performance of the system. Traffic bottlenecks are identified in different scenarios. We show that CS traffic is penalized by P2P traffic. However, if P2P traffic is handled at the metro level, the optical packet ring can carry much more traffic than if P2P traffic transits via the backbone network, mimicking CS traffic.