A Split Stack Approach to Mobility-Providing.pdf

A Split Stack Approach to Mobility-Providing Performance-Enhancing Proxies Brian D. Davison, Kiran Komaravolu, and Baoning Wu Computer Science Engineering Lehigh University Bethlehem, PA 18015 {davison,kkk2,baw4}@ November 2002 Abstract Many varieties of performance-enhancing proxies (PEPs) have been proposed to improve TCP performance and/or provide seamless mo- bility. One simple, albeit limited technique is the application-layer proxy. It too can isolate degraded last-mile link performance from the transmission of data across the rest of the network. While Web ser- vices on proxies are common, not all network applications will fit the traditional proxy model. We suggest using the proxy in a fashion that is fully compatible with all applications. In the split stack approach, the application runs on the client, but client networking library calls are executed on the proxy. The split stack architecture provides three major benefits, even with limited deployment: seamless handling of last-mile disconnects; mobility without MobileIP; and improved net- work performance. This paper outlines the split stack architecture, relates it to previous techniques, and provides some estimates of po- tential performance improvement. 1 Introduction Many varieties of performance-enhancing proxies (PEPs) have been pro- posed to improve TCP performance and/or provide seamless mobility [4, 7]. The typical approach requires protocol modification or stateful examination of packets at the IP or TCP layers. A simpler, albeit limited technique is the application-layer proxy. It too can isolate degraded last-mile link perfor- mance from the transmission of data across the rest of the network. While 1 Web services on proxies are common, not all network applications will fit the traditional proxy model. We suggest using the proxy in a fashion that is fully compatible with all applications. In the split stack approach, the application runs on the client, but client networking library calls are