Packet Switch Architectures for Very Small Optical RAM

One of the difficulties of optical packet switched (OPS) networks is buffering optical packets in the network. The traditional rule-of-thumb buffering approach needs huge buffers due to ultra high speed of optical networks. However, optical RAM is still under research and it is not expected to have large capacity, soon. The burstiness of Internet traffic causes high packet drop rate and low utilization in small buffered OPS networks. In this paper, we investigate and compare many optical switch architectures and pacing algorithms for minimizing the buffer size of OPS switches. We show that our XCP-based pacing control with shared buffering switch architecture gives a high TCP goodput when very small optical RAM buffers are used.