NAME

       lat_tcp - measure interprocess communication latency via TCP/IP

SYNOPSIS

       lat_tcp -s
       lat_tcp  [  -m <message size> ] [ -P <parallelism> ] [ -W <warmups> ] [ -N <repetitions> ]
       hostname
       lat_tcp -S hostname

DESCRIPTION

       lat_tcp is a client/server program that  measures  interprocess  communication  latencies.
       The  benchmark  passes  a  message  back and forth between the two processes (this sort of
       benchmark is frequently referred to as a ``hot potato'' benchmark).  No other work is done
       in the processes.

       lat_tcp  has  three forms of usage: as a server (-s), as a client (lat_tcp localhost), and
       as a shutdown (lat_tcp -S localhost).

OUTPUT

       The reported time is in microseconds per round trip and includes the total time, i.e., the
       context switching overhead is includeded.  Output format is like so

       TCP latency using localhost: 700 microseconds

ACKNOWLEDGEMENT

       Funding  for  the  development  of  this  tool  was  provided by Sun Microsystems Computer
       Corporation.

SEE ALSO

       lmbench(8), lat_fcntl(8), lat_fifo(8), lat_tcp(8), lat_udp(8), lat_unix(8).

AUTHOR

       Carl Staelin and Larry McVoy

       Comments, suggestions, and bug reports are always welcome.

(c)1994 Larry McVoy                           $Date$                                   LAT_TCP(8)