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>.