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NAME

tcpbench — TCP/UDP benchmarking and measurement tool

SYNOPSIS

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 display throughput statistics along with 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.

The options are as follows:

-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 addr

Specifies the IP address of the interface which is used to send the packets.

-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. Using this option requires read access to /dev/kmem.

-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 interval

Specify the statistics interval reporting rate in milliseconds (default: 1000).

-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 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. The default is 0.

-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>.