This is where we’ll use the TCP window options and parallel streams. There are many, many other parameters you can set that are beyond the scope of this article, but for our purposes, the main use is to prove out our bandwidth. Once installed, simply bring up the command line on both of the hosts and run these commands. Each test runs for 10 seconds by default, but virtually every setting is adjustable. It uses port 5001 by default, and the bandwidth it displays is from the client to the server. What’s even cooler is that because iPerf resides in memory, there are no files to clean up.
#Tamosoft throughput test vs iperf install#
There’s even a Java-based GUI you can install that runs on top of it called JPerf (JPerf is beyond the scope of this article, but I recommend looking into it). What’s so cool about iPerf is that you can test in real time any number of TCP window settings-even using parallel streams. When activated, it tries to send as much data down your pipe as it can, spitting out transfer statistics as it does. One side runs in a “server” mode, listening for requests the other end runs “client” mode, sending data.
#Tamosoft throughput test vs iperf windows#
IPerf is a simple, open source, command-line, network diagnostic tool that you install on two endpoints which can run on Linux, BSD, or Windows platforms. So what is iPerf, and how does it fit into all of this? Each OS is different and the default values will vary, but most all operating systems allow tweaking of the TCP stack and/or using parallel data streams. We do this by adjusting the “TCP Window”-telling TCP to send more data per flow than the default parameters. We can overcome BDP to some degree by sending more data at a time. This effect is called “Bandwidth Delay Product,” or BDP. Thus, the further away the two hosts, the longer it takes for the sender to receive the acknowledgment from the remote host, reducing overall throughput. But as the distance between two hosts increases, the speed of light remains constant. This “windowing” happens so fast that we don’t even notice it. This is called the “TCP Window.” Data travels at the speed of light, and typically, most hosts are fairly close together. To ensure proper delivery of data, it doesn’t send more until it receives an acknowledgment from the remote host that all data was received. In data transmission, TCP sends a certain amount of data and then pauses. In fact, the culprits are none other than TCP and the laws of physics. This issue is all too common and it has nothing to do with the network. The traceroute and MTR look fine-but where’s the performance and bandwidth you’re paying for? “What’s wrong with the network?” you wonder. To your shock, you see “Time Remaining: 10 Hours.” You may have experienced the following scenario yourself: You just provisioned a new bad-boy server with a gigabit connection in a data center on the opposite side of the globe. Two of the most common network characteristics we look at when investigating network-related concerns are speed and throughput. Troubleshoot speed and throughput issues with iPerf
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