A high speed transport protocol for datagram/virtual circuit networks

Abstract

We present a design and preliminary analysis of an end-to-end transport protocol that is capable of high throughput consistent with the evolving wideband physical networks based on fiber optic transmission lines and high capacity switches. Unlike the current transport protocols in which changes in control state information are exchanged between the two communicating entities only when some significant event occurs, our protocol exchanges relevant and full state information periodically, routinely and frequently. We show that this results in reducing the complexity of protocol processing by removing many of the procedures required to recover from the inadequacies of the network such as bit-errors, packet loss, out of sequence packets and makes it more amenable to parallel processing. Also, to increase channel utilization in the presence of high speed, long latency networks, and to support datagrams, we propose an efficient implementation of selective repeat method of error control used in our protocol. Thus, we utilize small extra bandwidth to simplify protocol processing; a trade-off that appears proper since electronic speeds for protocol processing are far slower than fiber transmission rates. Our preliminary estimates indicate that 20,000 packets/second can be handled in a completely software implementation on a 10 MIP microprocessor using 8% of its cycles.