Masking the overhead of protocol layering

Abstract

Protocol layering has been advocated as a way of dealing with the complexity of computer communication. It has also been criticized for its performance overhead. In this paper, we present some insights in the design of protocols, and how these insights can be used to mask the overhead of layering, in a way similar to client caching in a file system. With our techniques, we achieve an order of magnitude improvement in end-to-end message latency in the Horus communication framework. Over an ATM network, we are able to do a round-trip message exchange, of varying levels of semantics, in about 170 µseconds, using a protocol stack of four layers that were written in ML, a high-level functional language.