The effect of buffering strategies on protocol execution performance

The execution workload of a protocol often limits the data communications throughput in local area and wide area networks. The handling of buffers is one of the implementation factors that affects the execution workload of a protocol implementation: if possible, copying of user data should be avoided. Two buffer cut-through strategies for avoiding copying higher-level data are described, with some of the mechanisms necessary to implement them. The resulting execution workload in a transport protocol (similar to the ISO class 4 protocol) is studied in detail. Individual protocol actions are modeled for a wide range of data-stream parameters. The improvement when copying is avoided is shown to be relatively insensitive to the parameter values and to be as high as 80% when the checksum is not computed at the transport level