Feature Issue on Transmission in Optically Transparent Core NetworksOne of the difficulties of optical packet-switched (OPS) networks is buffering optical packets in the network. O(1) reading operation is not possible in the optical domain, because there is no equivalent optical RAM available for storing packets. Currently, the only available solution that can be used for buffering in the optical domain is using long fiber lines called fiber delay lines (FDL). However, FDLs have important limitations and may cause high packet drop rates due to the burstiness of Internet traffic. We propose an architecture using an explicit congestion control protocol (XCP) based utilization control algorithm designed for OPS wavelength-division-multiplexing (WDM) networks with pacing at the edge nodes for decreasing the buffer requirements at core nodes. We evaluate the FDL requirements on a meshed network with multiple-hop paths and show how FDL requirements change with slot size, utilization, FDL granularity, scheduling, and packet size distribution.
© 2007 Optical Society of AmericaPDF Article