A dynamic protocol stack configuration model for adaptation to communications environments

Differences in the quality of communication occur based on the conditions o f the network and the position where the client is connected when the clien t is communicating with a server distributing continuous media over a netwo rk. In this paper the authors propose a DPC (Dynamic Protocol stack Configu ration) to dynamically change the protocol stack for each flow based on the reliability and throughput of the data transfer when a client connected to a network is starting or maintaining communications with a server. In addi tion, the authors define dsocket, an expanded socket based on the DPC model , and DPCP (Dynamic Protocol stack Configuration Protocol) as a protocol to change the protocol stack through coordination between the client and the server. The authors demonstrate the validity of the DPC model by using it f or dynamic changes between TCP and UDP for changes in network load in a sys tem in which computers running this model under FreeBSD are connected via a wireless LAN or the Internet. (C) 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(3): 12-27,2001.