NAME

       tcpbench — TCP/UDP benchmarking and measurement tool

SYNOPSIS

       tcpbench -l
       tcpbench  [-46DRUuv]  [-B  buf]  [-b  sourceaddr]  [-k  kvars]  [-n  connections] [-p port] [-r interval]
                [-S space] [-T toskeyword] [-t secs] [-V rtable] hostname
       tcpbench -s [-46DUuv] [-B buf] [-k kvars] [-p port] [-r interval] [-S space] [-T toskeyword] [-V  rtable]
                [hostname]

DESCRIPTION

       tcpbench  is a small tool that performs throughput benchmarking and concurrent sampling of kernel network
       variables.

       tcpbench is run as a client/server pair.  The server must be invoked with the -s flag, which  will  cause
       it  to  listen  for  incoming  connections.   The client must be invoked with the hostname of a listening
       server to connect to.

       Once connected, the client will send TCP or UDP traffic as fast as possible  to  the  server.   Both  the
       client  and  server  will  periodically  compute  and  display  throughput statistics.  The server starts
       computing these for UDP on receipt of the first datagram, and stops for TCP when it has  no  connections.
       This  display  also  includes  any kernel variables the user has selected to sample (using the -k option,
       which is only available in TCP mode).  A list of available kernel variables may be obtained using the  -l
       option.

       A summary over the periodic throughput statistics is displayed on exit.  Its accuracy may be increased by
       decreasing  the  interval.   The  summary  bytes  and  duration cover the interval from transfer start to
       process exit.  The summary information can also be displayed while tcpbench is running by  sending  it  a
       SIGINFO signal (see the status argument of stty(1) for more information).

       The options are as follows:

       -4      Force tcpbench to use IPv4 addresses only.

       -6      Force tcpbench to use IPv6 addresses only.

       -B buf  Specify the size of the internal read/write buffer used by tcpbench.  The default is 262144 bytes
               for  TCP client/server and UDP server.  In UDP client mode this may be used to specify the packet
               size on the test stream.

       -b sourceaddr
               Specify the IP address to send the packets from,  which  is  useful  on  machines  with  multiple
               interfaces.

       -D      Enable debugging on the socket.

       -k kvars
               Specify  one  or  more  kernel  variables  to  monitor; multiple variables must be separated with
               commas.  This option is only valid in TCP mode.  The default is not to monitor any variables.

       -l      List the name of kernel variables available for monitoring and exit.

       -n connections
               Use the given number of TCP connections (default: 1).  UDP is connectionless so this option isn't
               valid.

       -p port
               Specify the port used for the test stream (default: 12345).

       -R      In client mode the write buffer size is randomized up to the size specified via -B.

       -r interval
               Specify the statistics interval reporting rate in milliseconds (default: 1000).   If  set  to  0,
               nothing is printed.

       -S space
               Set  the  size  of  the  socket  buffer used for the test stream.  On the client this option will
               resize the send buffer; on the server it will resize the receive buffer.

       -s      Place tcpbench in server mode, where it will listen on all interfaces for  incoming  connections.
               It defaults to using TCP if -u is not specified.

       -T toskeyword
               Change  the  IPv4  TOS  or  IPv6  TCLASS  value.  toskeyword may be one of critical, inetcontrol,
               lowdelay, netcontrol, throughput, reliability, or one of the DiffServ Code Points: ef,  af11  ...
               af43, cs0 ... cs7; or a number in either hex or decimal.

       -t secs
               Stop after secs seconds.

       -U      Use  AF_UNIX sockets instead of IPv4 or IPv6 sockets.  In client and server mode hostname is used
               as the path to the AF_UNIX socket.

       -u      Use UDP instead of TCP; this must be specified on both the client and  the  server.   Transmitted
               packets  per  second  (TX  PPS)  will be accounted on the client side, while received packets per
               second (RX PPS) will be accounted on the server side.  UDP has no Protocol Control Block (PCB) so
               the -k flags don't apply.

       -V rtable
               Set the routing table to be used.

       -v      Display verbose output.  If  specified  more  than  once,  increase  the  detail  of  information
               displayed.

SEE ALSO

       netstat(1), pstat(8)

HISTORY

       The tcpbench program first appeared in OpenBSD 4.4.

AUTHORS

       The tcpbench program was written by Damien Miller <djm@openbsd.org>.

       UDP mode and libevent port by Christiano F. Haesbaert <haesbaert@haesbaert.org>.

Debian                                           August 15, 2022                                     TCPBENCH(1)