On Tailoring Thread Schedules in Protocol Design: Experimental Results
Juan Carlos Gómez, Vernon J. Rego, Vaidy S Sunderam · Purdue e-Pubs (Purdue University System) · 1996
A number of factors motivate and favor the implementation of communication protocols in user-space.This motivation is particularly strong in the context of providing multiway connectionless transport for distributed computing, multimedia, and conferencing applications.Here, protocol implementations can hold the key to optimal functionality and performance.As part of a larger study investigating experimental strategies for general multiway, connectionless transport for a variety of applications and multiple media, we report our experiences with the implementation of an unreliable transport mechanism.This step is a precursor to multiway reliable transport.We focus on the use of user-space threads and UDP-based protocol actions, presenting strategies for scheduling threads that either do a client's application-processing or retrieve packets from a client's network receive buffer.Efficient packet retrieval is crucial especially when transport is reliable, because higher packet-loss implies longer network delays.With experiments performed on a Sun SPARe 5 LAN environment, we show how different threads scheduling strategies yield different levels of application-processing efficiency and packet-loss.