Re-thinking the End-to-end Paradigm - The Missing Protocol Layer
Erling Kristiansen, José Neves, J.M. Brazio, Giampiero Pagano, Sergio Palazzo · 2004
The End-to-end paradigm is a central principle in the way the Internet and the Internet communicati on protocols work. This paradigm has proved extremely robust and versatile; without it, the Internet might not have been the global, universal network it is today. There are, however, some environments in which the paradigm leads to inferior performance and sub-optimal utilisation of, often expensive, communication resources. This is particularly the case for TCP, the reliable end-to-end transport protocol. Such environments include satellite links and terrestrial mobile links. A variety of “performance enhancers” have been proposed for such environments, and some are deployed. Such enhancers, however, break the end-toend nature of the network to a greater or lesser extent. This paper argues that the introduction of an additional protocol layer, the sub-network transport layer, provides an attractive solution to the mentioned problems. An architecture incorporating such a layer is presented, and results of simulations and tests by two independent industrial consortia are reported. The overall conclusion of the paper is that the approach is valid and provides significant performance improvements in some environments where the standard Internet protocols perform poorly.