Data Logistics in Network Computing: The Logistical Session Layer

In this paper we present a strategy for optimizing end-toend TCP/IP throughput over long-haul networks (i.e. those where the product of the bandwidth and the delay is high.) Our approach defines a Logistical Session Layer (LSL) that uses intermediate process-level “depots” along the network route from source to sink to implement an end-to-end communcation session. Despite the additional processing overhead resulting from TCP/IP protocol stack Unix kernel boundary traversals at each depot, our experiments show that dramatic end-to-end bandwidth improvements are possible. We also describe the prototype implementation of LSL that does not require Unix kernel modification or root access privilege that we used to generate the results, and discuss its utility in the context of extant TCP/IP tuning methodologies.