Linux Networking Cookbook

19.9. Measuring Throughput, Jitter, and Packet Loss with iperf

Problem

You want to measure throughput on your various network segments, and you want to collect jitter and datagram loss statistics. You might want these just as a routine part of periodically checking your network performance, or you're running a VoIP server like Asterisk, Trixbox, or PBXtra, so you need your network to be in extragood shape to have good call quality.

Solution

Use iperf, which is a nifty utility for measuring TCP and UDP performance between two endpoints. It must be installed at both ends of the connection you're measuring; in this example, that is Xena and Penguina. We'll call Xena the server and Penguina the client. First, start iperf on Xena in server mode, then fire it up on Penguina. (The easy way is to do all this on Xena in two X terminals via SSH.)

	carla@xena:~$ iperf -s
	------------------------------------------------------------
	Server listening on TCP port 5001
	TCP window size: 85.3 KByte (default)
	------------------------------------------------------------

	terry@penguina:~$ iperf -c xena
	------------------------------------------------------------
	Client connecting to xena, TCP port 5001
	TCP window size: 16.0 KByte (default)
	------------------------------------------------------------
	[  3] local 192.168.1.76 port 49215 connected with 192.168.1.10 port 5001
	[  3] 0.0-10.0 sec 111 MBytes 92.6 Mbits/sec

And it's done. That's a good clean run, and as fast as you're going to see over Fast Ethernet. ...