linear search of TCP control blocks on demultiplexing of an incom ing IP datagram

["Vishnepolsky, Oleg" <[e-mail]>]

Which TCP implementations do a hash lookup ? I know that most BSD
derivatives do a linear search, except for the freebsd stack which does a
hash. What about MS stacks ? My stacks (OS/2, FlexOS) being BSD derivatives
used linear search except I used a one control block cache lookup since most
of the TCP packets come in "trains". I had a 70% hit ration in my
experiments.
Is there a study/comparison of various TCP stacks re this and many other
characteristics ? I am aware of external TCP fingerprinting  but that does
not reveal the internals that much. Any help will be appreciated.
Oleg Vishnepolsky