Optical Packet Buffers for Backbone Internet Routers

If optical routers are to become reality, we will need several new optical technologies, one of which is to build sufficiently large optical buffers. Building optical buffers for routers is daunting: Today´s electronic routers often hold millions of packets, which is well beyond the capabilities of optical technology. In this paper, we argue that two new results offer a solution. First, we show that the size of buffers in backbone routers can be made very small-just about 20 packets per linecard-at the expense of a small loss in throughput. Second, we show that integrated delay line optical buffers can store a few dozen packets on a photonic chip. With the combination of these two results, we conclude that future Internet routers could use optical buffers.