iPERF Throughput Test

iPERF Throughput Test

Iperf is a handy tool to measure the bandwidth and the quality of a network link. It is a commonly used network testing tool that can create Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) data streams and measure the throughput of a network that is carrying them.

Iperf allows the users to vary various parameters that can be used for testing the network, or alternatively for optimizing and tuning a network. Iperf has a client and server functionality, and can measure the throughput between the two ends, either unidirectionally or bi-directionally.

Iperf can be installed very easily on any Linux or Microsoft Windows system, where one host can be configured as a client, the other one as server.

Setup required for running the iperf test:

1. Download the iperf setup, you can download it from: https://iperf.fr/
2. Copy the setup file on the two hosts you would be using to perform the test.
3. Set one host in the server mode and the other in the client mode with the following syntax:

To set the host in server mode use the command : iperf -s

C:\IOS Images\iperf-2.0.5-2-win32>iperf -s
Server listening on TCP port 5001
TCP window size: 64.0 KByte (default)

To set the client in client mode use the command : iperf -c <server ip address>

C:\IOS Images\iperf-2.0.5-2-win32>iperf -c      // Where is server ip address.

The other parameters available in iperf are:

C:\IOS Images\iperf-2.0.5-2-win32>iperf –helpUsage: iperf [-s|-c host] [options]       iperf [-h|–help] [-v|–version]

-f, –format [kmKM] format to report: Kbits, Mbits, KBytes, MBytes
-i, –interval # seconds between periodic bandwidth reports
-l, –len #[KM] length of buffer to read or write (default 8 KB)
-m, –print_mss print TCP maximum segment size (MTU – TCP/IP header)
-o, –output output the report or error message to this specified file
-p, –port # server port to listen on/connect to
-u, –udp use UDP rather than TCP
-w, –window #[KM] TCP window size (socket buffer size)
-B, –bind bind to , an interface or multicast address
-C, –compatibility for use with older versions does not sent extra msgs
-M, –mss # set TCP maximum segment size (MTU – 40 bytes)
-N, –nodelay set TCP no delay, disabling Nagle’s Algorithm
-V, –IPv6Version Set the domain to IPv6

Server specific:
-s, –server run in server mode
-U, –single_udp run in single threaded UDP mode
-D, –daemon run the server as a daemon

Client specific:
-b, –bandwidth #[KM] for UDP, bandwidth to send at in bits/sec
(default 1 Mbit/sec, implies -u)
-c, –client run in client mode, connecting to
-d, –dualtest Do a bidirectional test simultaneously
-n, –num #[KM] number of bytes to transmit (instead of -t)
-r, –tradeoff Do a bidirectional test individually
-t, –time # time in seconds to transmit for (default 10 secs)
-F, –fileinput input the data to be transmitted from a file
-I, –stdin input the data to be transmitted from stdin
-L, –listenport # port to receive bidirectional tests back on
-P, –parallel # number of parallel client threads to run
-T, –ttl # time-to-live, for multicast (default 1)
-Z, –linux-congestion set TCP congestion control algorithm (Linux only)

-x, –reportexclude [CDMSV] exclude C(connection) D(data) M(multicast) S(settings) V(server) reports
-y, –reportstyle C report as a Comma-Separated Values
-h, –help print this message and quit
-v, –version print version information and quit

[KM] Indicates options that support a K or M suffix for kilo- or mega-

Use the syntax with some additional parameters ” iperf.exe – c -P 10 -w 1000k ” ( -P refers to the number of parallel TCP streams and –w referes to the TCP window size )

Happy Reading….