The 80s witnessed the rise of fine talent - so, it is only fitting to dedicate another complete playlist for the 80s. Here it is. Enjoy. Earlier playlists can be accessed from the following locations:
iperf is a simple, open source tool to measure the network bandwidth. It can test TCP or UDP throughput. Tools like iperf are useful to check the performance of a network real quick, by comparing the achieved bandwidth with the expectation. The example in this blog post is from a Solaris system, but the instructions and testing methodology are applicable on all supported platforms including Linux.
Download the source code from iperf's home page, and build the iperf binary. Those running Solaris 10 or later, can download the pre-built binary (file size: 245K) from this location to give it a quick try (right click and "Save Link As .." or similar option).
Testing methodology:
iperf's network performance measurements are based on the client-server communication model - hence requires establishing both a server and a client. The same iperf binary can be used to run the process in server and client modes.
Start iperf in server mode
iperf -s -i <interval>
Option -s or --server starts the process in server mode. -i or --interval is the sampling interval in seconds.
Start iperf in client mode, and test the network connection between client and the server with arbitrary data transfers.
iperf -n <bytes> -i <interval> -c <ServerIP>
Option -c or --client starts the process in client mode. Option -n or --bytes specify the number of bytes to transmit in bytes, KB (use suffix K) or MB (use suffix M). -i or --interval is the sampling interval in seconds. The last option is the IP address or the hostname of the server to connect to. By default, client connects to the server using TCP. -u or --udp switches to UDP.
Check the network link speed on server and client, and compare the throughput achieved.
Check the man page out for the full list of options supported by iperf in client and server modes.
Here is a simple demonstration.
On server node:
iperfserv% dladm show-phys net0 LINK MEDIA STATE SPEED DUPLEX DEVICE net0 Ethernet up 1000 full igb0
client% ./iperf -n 1024M -i 1 -c 10.129.193.63 Connecting to host 10.129.193.63, port 5201 [ 4] local 10.129.193.151 port 63507 connected to 10.129.193.63 port 5201 [ ID] Interval Transfer Bandwidth [ 4] 0.00-1.01 sec 105 MBytes 875 Mbits/sec [ 4] 1.01-2.02 sec 112 MBytes 934 Mbits/sec [ 4] 2.02-3.00 sec 110 MBytes 934 Mbits/sec [...] [ 4] 8.02-9.01 sec 110 MBytes 933 Mbits/sec [ 4] 9.01-9.27 sec 30.0 MBytes 934 Mbits/sec [ ID] Interval Transfer Bandwidth Sent [ 4] 0.00-9.27 sec 1.00 GBytes 927 Mbits/sec Received [ 4] 0.00-9.27 sec 1.00 GBytes 927 Mbits/sec
iperf Done.
At the same time, somewhat similar messages are written to stdout on the server node.
iperfserv% ./iperf -s -i 1 ----------------------------------------------------------- Server listening on 5201 ----------------------------------------------------------- Accepted connection from 10.129.193.151, port 33457 [ 5] local 10.129.193.63 port 5201 connected to 10.129.193.151 port 63507 [ ID] Interval Transfer Bandwidth [ 5] 0.00-1.00 sec 104 MBytes 874 Mbits/sec [ 5] 1.00-2.00 sec 111 MBytes 934 Mbits/sec [ 5] 2.00-3.00 sec 111 MBytes 934 Mbits/sec [...] [ ID] Interval Transfer Bandwidth Sent [ 5] 0.00-9.28 sec 1.00 GBytes 927 Mbits/sec Received [ 5] 0.00-9.28 sec 1.00 GBytes 927 Mbits/sec ----------------------------------------------------------- Server listening on 5201 -----------------------------------------------------------
The link speed is specified in Mbps (megabit per second). In the above example, the network link is operating at 1000 Mbps speed, and the achieved bandwidth is 927 Mbps, which is 92.7% of the advertised bandwidth.
Notes:
It is not necessary to execute iperf in client and server modes as root or privileged user
In server mode, iperf uses port 5201 by default. It can be changed to something else using -p or --port option
Restart iperf server after each client test to get reliable, consistent results
Using iperf is just one of many ways to measure the network bandwidth. There are other tools such as uperf, ttcp, netperf, bwping, udpmon, tcpmon, .. just to name a few. Research and pick the one that best suits your requirement.
The quality of music steadily improved over the decades in mid-1900s, and eventually peaked in the 80s. Some may disagree, but in my opinion, the 80s were easily one of the best decades for music in the United States. The decade witnessed the emergence of many successful artists who delivered solid hits, that are still relevant and part of many pop culture references today. The launch of MTV in 1981 upped the ante to produce interesting videos in an effort to increase the global outreach.
In this iteration, let's focus on the decade of eighties. The following playlist has some random songs from the 80s in no particular order. The previous playlist can be accessed from this location: