Recently actual use of the OSI standardized protocols has begun on cli
ent-server systems of LANs, and reduction of OSI protocol overheads in
high-speed networks has become more important. We studied a parallel-
processing architecture for Message Handling System (MHS), which requi
res a large amount of protocol processing and is expected to be used w
idely. We implemented a prototype MHS server with performance scalable
to number of CPUs, by porting an existing MHS software with minimum m
odification. This paper reports on the parallel processing scheme, har
dware and software architecture of the prototype, as well as evaluatio
n of the scheme based on measurement and simulation.