Iperf test large file. 0 sec 109 MBytes 91. The -c command designates this workstation as the “client” and the IP address of the server. Oct 6, 2017 · Run A Server. Now, you can try connecting to it from another computer on your network. To test both connection streams, run the following command from the client side: iperf -c 198. Feb 10, 2011 · 0. It lists all of extensive options available for running Iperf in either server or client This impacts large data sets of small files because each file is written to disk when transferred. - Datagram loss: can be measured with an Iperf UDP test. On the server I set up a SimpleHTTPServer using python and the client is a laptop i norway. Iperf 2 also supports --full-duplex for same socket full duplex traffic. Y. For details, see iPerf documentation. Sep 3, 2018 · To run iperf server you need to simply type: iperf3 -s. txt file. 67 seconds to send 10% of the 31. Download iPerf. The actual test data is sent over a separate TCP connection, as a separate flow of UDP packets, or as an independent SCTP connection, depending on what proto-col was specified by the client. For each test it reports the measured throughput / bitrate, loss, and other parameters. So while the test will mimic an actual file transfer, the data stored to disk may not be the same as what was sent. Jan 31, 2007 · A bi-directional test, which is the -d option, runs both ways: terry@uberpc:~$ iperf -c xena -d ' 4' 0. DESCRIPTION. Now, on iPerf, I am trying to use "-F" option like this: -c serverIp -F testFile. iperf has client and server functionality, and can create data streams to measure the throughput between the two ends in one or both directions. 51. Jun 15, 2018 · iperf_server_api. JPerf comes equipped with Iperf and its only goal is to take command line out of setup picture. Step 2 Setup the iPerf Server and Client to measure the speed of the router (LAN to LAN) When using iPerf to test the speed, we need to set one PC as a server and another PC as a client. Which is like 25% lower than the iPerf throughput. Jul 5, 2023 · To test the raw network bandwidth, you can use iperf (or iperf3). Now start the test on the client. e version 3 in both cases. Example: If the file is on your desktop, then you would use the following in the command prompt: cd C:\Users\Administrator\Desktop\iperf-2. What is iPerf / iPerf3 ? iPerf3 is a tool for active measurements of the maximum achievable bandwidth on IP networks. See image below. Y 9999 And in the target Y. 10, port 5201. To perform an iperf test the user must establish both a server (to discard traffic) and a client (to generate traffic). I carried out a network throughput test using iperf and captured packets at both ends. I think that means that it took 0. Jan 12, 2015 · In some cases, you may want to test both servers for the maximum amount of throughput. However, the iperf is showing me the following error: Nov 29, 2023 · Iperf is a command-line tool that measures TCP and UDP bandwidth performance. Written instructions with more examples: https://networkv May 19, 2016 · Each file transfer is running at a rate of 500 KB/s (4 Mbits/sec). On another PC, the client is sending traffic to this IP address. 8 Mbits/sec for a single TCP stream. 5 days ago · Downloading Iperf/Jperf for Windows & Linux - Compiling & Installing on Linux. Mar 18, 2024 · First, we need to initiate the server. c:243 - end timer; iperf_server_api. iPerf is a great way to test your LAN speed (rather than your Internet speed, as the two previous tools do). Step 2. Run a 30-second test, giving results every 1 second: iperf3 -c 10. I set up a Iperf server on the dedicated box and connected to it using the same client and got the following results iPerf - The ultimate speed test tool for TCP, UDP and SCTP It is connected via 10GbE switch with my PC. We need to install iPerf on both the client and the server: $ sudo apt install iperf. 137 signifies the IP address of the server to which client is to be connected. The Windows application is a simple executable run from the command line, thus no software has to be installed or configured. c:440 - negative result from select is handled; after long test (15 minutes) this happened: no termination message from client arrived (yet) control socket is closed in server_timer_proc timer handle at iperf_server_api. If you run the iPerf server with a larger TCP window, you can use the following command to get maximum network utilization: iperf3. 110. 5 -d. ) Feb 16, 2010 · If you are not acquainted with Iperf – it is one of the most flexible tools to run bandwidth test, although somewhat limited by being command line utility. 9 directory: Here is how the bin/ directory originally looks: And here is what it looks like after copying the iPerf 2. Connect your Laptop B wirelessly to the wireless network of the EAP. When the test is completed the output from the server looks like this: We suggest only testing the large files if you have a connection speed faster than 10 Mbps. - Jitter (latency variation): can be measured with an Iperf UDP test. A copy can be found at iperf. General Options-f, --format [kmKM] format to report: Kbits, Mbits, KBytes, MBytes -h, --help print a help synopsis Jun 28, 2016 · For a Microsoft Windows system, you need only download the zip file for Windows, unzip the contents of the file, and then move the two files within the zip file, which are cygwin1. It can test either TCP or UDP throughput. The downloadable zip file contains the Windows and Linux version of Iperf, along with the Java-based graphical interfaces (Jperf). Since it can be tricky to get access to the public servers listed on the iPerf website, I spun up my own server in Azure to test against: > iperf3. For the first test, run the test as we did before using the following commands: Server: iperf3 -s; Client: iperf3 -c 172. Here is the command : start "LocalFLServer" iperf -s -w 1024k -i 2 -B 10. Iperf is available as a free download from our Administrator Utilities download section. 168. At the end of the test, Iperf will tell you the amount of jitter as well as the amount of dropped packets in the transmission. I have an unofficial M. with iperf3, you can see the output in json format: The command: iperf3 -c <server-ip> -w 4000 -t 10 -i 2 -f MBytes -V -J --logfile test. 1. At its most basic, that’s super easy. As you can see below a test was run (from client to server) displaying the transfer rate (MB) and bandwidth This video shows you how to use iPerf for Windows as well as Linux to test bandwidth on your network. The quality of a link can be tested as follows: - Latency (response time or RTT): can be measured with the Ping command. 2. Open a command prompt or terminal and navigate to the iperf3 executable. 7. Common options: -t – time to transmit for (default 10 seconds) -i – interval time to report stats (default 1 second) For example, to test for 60 seconds with 5 second intervals: $ iperf3 -c 192. To run the network throughput test of a client, specify the address (or DNS name) of the iPerf server: iperf3. Also, for anyone using this as a guide, I deleted all the tunables I added and continued getting Feb 1, 2010 · In the device list, select the switch/router you want to get the information from. File Mebioctet 2 X Octet Kio Octet; 1 Mio file: 1 mebioctet: 2 20 octets : 1,024 Kio: 1,048,576 octets: 10 Mio file: 10 mebioctet: 10 x 2 20 octets: May 14, 2024 · 2. Continue using iperf3 -s to run the server. zip file. This version, sometimes referred to as iperf3, is a redesign of an Apr 15, 2015 · I've created a file of size 1 MB using the following command in Linux: dd if=/dev/zero of=testFile bs=1k count=1000. Now let’s run the UDP test from the client: iperf -c -u. To change your directory to desktop, simply type “cd desktop” and hit the enter key. By default, the server is listening on port 5201. x results are inconsistent for UDP above 2Gbps. Here, c signifies the client mode. Download the iperf utility. 18. Try running with the -P Flag. You did send 10GB. Fasterdata. It can be used to test the performance of your network connection between two hosts. May 9, 2023 · To run a bi-directional test, meaning you measure bandwidth in both directions simultaneously, use the -d option. 10. I see a almost 10% packets highlighted in tcp. txt or iperf3 -s -D > listen. On the server run: iperf --server --udp. On the server: iperf -s -u -i 1. This can easily be done using the built-in bidirectional testing feature iPerf offers. The video s iperf test shows large number of TCP: duplicate ACK / retransmission & out-of-order. If you push close in cmd this file text. Jan 27, 2015 · I downloaded the Windows version of Iperf, release 1. I’ve used the Mynikko Dummy File Creator in the link below. On the client host, connect to the server IP and port: $ iperf3 -c <server_ip>. 22 -i2 -t30 -b 1G -u; Using a 20GB file: Server: iperf3 -s Mar 12, 2024 · You can use iPerf to quickly measure the maximum network bandwidth (throughput) between a server and a client, and conduct stress testing of the ISP link, router, network gateway (firewall), your Ethernet, or Wi-Fi network performance. I guess with RAIDZ was the bottle neck for the write speeds! = ( lol. Network jitter = 0. 15, port 5201. You also made the lengths of your sends tiny (32K) which is probably part of your problem. com --port 5210. exe, if you downloaded a version 3 release of the software, to whatever directory you wish to keep the program in. log. (B == bytes, b == bits, naturally). iperf's Transfer column is in MebiBytes: 1,048,576's of 8-bit Bytes. dll and iperf3. x -P 10 Apr 2, 2013 · Bandwidth = 81. If you prefer to change the port you can run: iperf -s -p 2323 Iperf client node. It is a cross-platform tool that can produce standardized performance measurements for any network. But it is not working. You will see different IDs per connection/socket. When transferring a large file via SMB or iSCCi share, I „only“ get 800MB/s transfer rate. 0 sec 84. file With this method, the max speed I can get is:390KiB/s. These files will automatically use IPv6 if available, but you can select the IPv4 or Feb 22, 2020 · In order to test UDP performance, simply enter “iperf3. Connecting to host 10. iperf3 is normally used to measure memory to memory performance, but you can also use iperf3 for determine if the. [2] Symptoms. Aug 22, 2018 · Unzip the iPerf bundle in a directory; Copy all the unzipped files of iPerf 2. In particular, the file size will be rounded up to the next larger multiple of the transfer block size, and for UDP tests, iperf’s metadata (containing timestamps and sequence numbers) will overwrite the start of every UDP When Testing connection to server via libre speed I get 8000 Mbps down and 4000 up. iperf is a tool for active measurements of the maximum achievable bandwidth on IP networks. Nov 22, 2021 · I highly recommend using a test file for testing speeds, as noted in the text file commands. iPerf Example For the most basic speed test, which is all you need 99% of the time, run the following with -c for client mode: iperf3 -c <ip address of server>. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. answered Dec 15, 2017 at 6:26. For each test it reports the bandwidth, loss, and other parameters. c:243, test->state is still TEST_RUNNING Jun 5, 2022 · This video shows you how to use iPerf to test network bandwidth and the throughput on your network. 3. Note: In this case make sure you can run iperf client and server same version i. 200 -P 8 -t 30 -w 32768. It supports tuning of various parameters related to timing, buffers and protocols (TCP, UDP, SCTP with IPv4 and IPv6). 6. Full installation instructions are available within the . exe -c [IP address of server] -u”. 5 MBytes 70. Your assumption is partly right. txt client: iperf3 -c <server-ip> -B <client-ip> > send. 20. Not really much to go wrong. On your laptop, press windows key + R, put CMD in the Open bar can click OK. May 15, 2020 · Testing available network bandwidth with TCP. Then disk to memory: server: iperf3 -s. On the server that will be sending data, open an elevated command window and run the The network link is delimited by two hosts running Iperf. The click create. For example, the iperf3 test from my workstation to my Proxmox server (running iperf3 -s). On the server that will be sending data, open an elevated command window and run the Aug 25, 2017 · 0. My question is this, when someone runs an iPerf test on a link and the % packet loss comes back let's say at 10%, does that mean that 100 out of every Because the size of files sent is probably way 2 small to get optimal performance. Jul 22, 2020 · IPerf is an open-source tool designed to test network bandwidth between two network nodes. 9 and paste them in the bin directory; In more detail, here are the files that need to be copied from the unzipped iPerf 2. 2Mb/s and 6. Iperf works for both TCP and UDP traffic with Sep 6, 2014 · You will see all the process in the server machine. exe --client iperf. iperf's Bitrate column is in megabits: 1,000,000's of 1-bit bits. Feb 24, 2021 · For this test, 52GB and 20GB files were used, running from the client to the server machine. 67 seconds before ending. cageops. 4Mb/s. Just use the -s flag. After that, we need to connect to the server from the client machine. To measure the throughput of your network you need to run iperf client node which will connect to Iperf Hello, I'm a noob when it comes to iPerf, I only know what i've read online over the past couple of days and have never used the application myself. There are roughly 8. 2. Then, knowing the size of the file and the time, you can calculate the approximate Apr 18, 2017 · I am trying to start iperf server in background and redirect the output to a file. Jul 4, 2017 · 4. Type iperf3 -c SERVER-IP-OR-NAME to start the iPerf client, replacing SERVER-IP-OR-NAME with the IP address or hostname of the iPerf server. On the client side we just need to add the -u flag to start sending UDP packets instead of TCP packets. client: iperf3 -c testhost -F filename -t 60. Replace <server_ip_address> with the IP address of the server that you want to test your network speed to. #1. 2 --udp --time 10 --bandwidth 100M. 2 in my PC. or iperf -s if you installed iperf instead of iperf3. 5 Gb. Jul 24, 2019 · July 24, 2019. This field represents sp->result->stream_retrans. x. Note: you can't test between a host Mar 19, 2024 · When testing between two nodes, one node acts as the server, and the other node acts as a client. On the server that will be receiving data, open an elevated command window and run the following command: "iperf. exe file. This is a new implementation that shares Oct 6, 2021 · Symptoms. iperf3. Iperf gets me 2 Gb speed. iperf3 -c <server_ip_address>. Starting the second sftp session does not affect the speed of the first one iota. High jitter and lots of dropped packets will result in issues in VoIP calls, online gaming, etc. 15. Here, -s signifies the server mode. ) Latency measurements include both one way delay (OWD) and round trip times (RTTs. Real-Time Reporting: During the network test, "iperf" provides real-time feedback and statistics, including the measured bandwidth, packet loss, latency, and jitter. ) Mar 2, 2021 · Just open command prompt, navigate to where the iPerf binary is and run it against a iPerf server. After your test, on the client machine in cmd need push ctrl+ c and after (y). 100. iperf -c 192. The speeds i was seeing ranged between 3. iPerf benchmark gives me about 8. Dec 31, 2018 · We would like to show you a description here but the site won’t allow us. 0, from the Iperf website and extracted the files on both a Vista and XP Pro PC. Description. Jul 25, 2017 · Stack Exchange Network. Debian, Raspbian, and Ubuntu users can install it with apt: sudo apt install iperf. Measuring the download speed from the server Jun 6, 2017 · Jun 6, 2017. exe -c 192. For example it shows three rows of data but I don't know which corresponds to send and which to receive. Now let’s set up the client and server to run a UDP-based test. Connecting to host iperf. C:\TEMP\iperf3 -c 10. Sep 7, 2023 · Running iPerf tests. The other columns I can guess, but I would rather be sure. I get 250 MBps read via cd mark. To restart the test, refresh the web page. fr. Apr 29, 2024 · Copy these two files to the path C:\Windows\System32, and then the installation is complete. If you are doing the test with server's on the other side of the globe, then you might see higher jitter values in iperf output. How to test available network bandwidth. vikram jeet singh. Lost/Total = 49/69508. It sends traffic from one host to another and measures the amount of traffic that is transferred. To test your connection to one of the computers on your own network, you need to run Iperf as a server. $ iperf3 -c 192. To run a quick TCP bandwidth test, first start iperf in server mode from a server you control: iperf -s. stevesinchak@tweaks ~ % iperf3 -c 10. On the server that will be sending data, open an elevated command window and run the Symptoms. If you want to get server results in the client output, use the --get-server-output option. 3,466 2 22 22. You can use iPerf to quickly measure the maximum network bandwidth (throughput) between a server and a client, conduct stress testing of the ISP communication channel, router, network gateway (firewall), your Ethernet or Wi-Fi network. SOLVED: So I created a stripe/RAID0 and iperf continued giving me the exact same results, however, with a ramdisk I was getting full 10gbe throughput both ways. In this test we will send UDP data at 100Mb/s for 10 seconds: iperf --client 192. txt after that collect all information about this period. 0-10. 120 -p5003 I want to pipe its output to a txt file, so I tried both Nov 17, 2022 · 5) Perform iPerf test on the host machine which is connected to SSL-VPN: All the iPerf tests will be performed using an internal server as iPerf server which will be used for file transfer. 137 -u 100. Symptoms. This is quite slow, as iperf tests show a rate of 16. A fast user-space file transfer protocol that uses TCP control and UDP data for transfer over very high speed long distance networks (≥ 1 Gbps and even 10 GE), designed to provide more throughput than possible with TCP over the same networks. 0. server: iperf3 -s -D >> /tmp/listen. If you look at the output, it's only sending for 0. Aug 21, 2018 · Now to start a test, go onto the client and enter iperf -c -i 1. For Disk to Disk testing, you would do this: 1st test memory to memory: server: iperf3 -s. While FileCatalyst is a premium file acceleration tool, its speed is defined by both the hardware and network on which it is used. If your connection is fast enough to completely download the large file, the download restarts (seen in the graph by a vertical red line). This is crucial for testing connections of 10Gbps or higher (opposed to a wget command to download a test file that only holds one connection unable Mar 14, 2019 · If you want to know how to use iperf, you need only two basic commands. 9 files in it: We would like to show you a description here but the site won’t allow us. The Linux version is easily installed using the procedure outlined below. The bandwidth is measured through TCP tests. First, run a server on a device with iperf3 -s. When testing with UDP, no changes are required on the server side. You might also need larger socket buffers (TCP window size) to get 10Gbps. So these are retransmission. Once this test is completed, we recommend that you reverse the roles of the nodes to test both upload and download throughput on both nodes. 4 megabits per MebiByte. txt will be empty. 1 -f K -w 500K -R --get-server-output. 1 -f K -w 500K -d. flag with following characteristic: “TCP duplicate ack” followed by “TCP fast restransmission / TCP Jul 27, 2018 · To run the Iperf executable file, open the command prompt. The performance metrics supported include throughput and latency (or link capacity and responsiveness. Any idea of what protocol or method could I use to get speed like when using iperf ~ 3MiB/s Oct 13, 2020 · iPerf UDP Test. 5Gbit/s throughput. You can use something as simple as: on the server: iperf -s; in the client: iperf -c <server_ip> then, reverse the server and client roles; To test rsync transfer rate, which it is often limited by SSH encrypt/decrypt speed, you can create a sparse source file and sync it to the Jan 12, 2014 · If I use iperf with -y C and -r arguments to test bidirectional transfer and export it as a CSV. network or the disk is the bottleneck. Then, you can test the connection to that server by running iperf in client mode from another server with iperf -c <host> where <host> is the address of the iperf server you just started above. If the download does not start you may have to right click on the size and select "Save Target As”. to: "read from the file and write to the network, instead of using random data". Open a command prompt and navigate to the folder containing the iperf. 42. Measuring Internet speed by downloading a large file. 94 Mbits/sec is the max rate you can get for TCP/IP throughput on 100 megabit Ethernet with standard sized frames. ) and measure the time it takes to download the file. First, try to generate traffic using parallel sessions to the server using the following command: iperf3 -c x. 167 ms (network jitter is the deviation in time for periodic arrival of data gram's. Try rerunning it with the debug flag, and grab a packet capture to figure out which end initiates the termination. file | lz4c | nc Y. ) So in the end this is the file descriptor of the socket (which translates to an int). Nov 18, 2021 · To achieve the fastest possible file transfer speeds, you can run a network test using iPerf3 to ensure your system is clean and free of bottlenecks before implementing a fast file transfer solution. Recommended open this file in NotePad or WordPad for the Jul 28, 2023 · Disk Testing using iperf3. The test runs for 20 seconds, and then automatically stops. Now at bottom select the In/Out Errors/Discarded Packets in the roll-down menu, then select the interface, where you want to create the counter on. 113. Jul 10, 2021 · pv 100GB. After that, we should check if it’s installed: $ iperf --version. txt on client but on server, I don't see anything being written in any file. 165. I get some output but the problem is that I don't know what the column names are. Connect the iperf3 client. This can be done by typing the “cmd” into the search field after you have clicked on the start button. 2 Ssd storage Pool which I transfer onto from another M. Get Server Network Results in the Symptoms. 1MB file. 200. Jan 24, 2020 · iPerf. iperf 2 is a testing tool which performs network traffic measurements using network sockets. Note that iperf 2. With iperf 2 on can use --reverse or -R (for non-windows) to reverse the traffic and get through a NAT firewall. On the server that will be sending data, open an elevated command window and run the Dec 23, 2020 · cd c:toolsiperf. On the server that will be sending data, open an elevated command window and run the Oct 23, 2023 · Step 1. the same networks. txt I am able to see output in send. exe –s –w 2m". That's 2 MB/sec. In addition to the throughput measurement it can also report metrics such as packet loss and jitter. Iperf is an open source network performance measurement tool that tests throughput. If you want to keep the server running in Lets first consider the performance of UDP over the simple test network. Default length size is 128K for TCP. iPerf - The ultimate speed test tool for TCP, UDP and SCTP The downloadable zip file contains the Windows and Linux version of Iperf, along with the Java-based graphical interfaces (Jperf). Mar 8, 2020 · This is a tutorial showing how to test network performance using a tool called IPerf. 5-2-win32. Here is the result on the client: You can adjust the bandwidth from the default 1Mb/s. iperf, Iperf, or iPerf, is a tool for network performance measurement and tuning. This field is only displayed when retransmissions appeared (0 is not Jul 10, 2020 · Just run the below command on the server machine and it will initiate the server. analysis. com, port 5210. This will measure the bandwidth between the two on a period of 60 seconds, which is large enough to get a real measurement. ) Iperf can use both TCP and UDP sockets (or protocols. . Join our Discord Community of DevOps/Network Engineers:? Aug 22, 2016 · Downloading files using http gave me unsatisfactory speeds. . client: iperf3 -c testhost. Y host: nc -l 9999 | lz4c -d -| pv > 100GB. 192. The latest version of iperf3 now supports disk to disk testing. The iPerf allows to generate TCP and UDP traffic/load between two hosts. iperf can test multi-cast performance by running several servers listening on your multi-cast address: Do a bidirectional test simultaneously -n, --num n[KM] number of bytes to transmit (instead of -t) -r, --tradeoff Do a bidirectional test individually -t, --time n time in seconds to transmit for (default 10 secs) -F, --fileinput <name> input the data to be transmitted from a file -I, --stdin input the data to be transmitted from stdin -L Static download test. To stop the test early, close the web page. After downloading iPerf: 1. 1. Next, change your directory to the directory housing the Iperf folder. 8 Mbits/sec Debugging multi-cast network problems can drive you buggy. These metrics help users assess the quality and performance of the network connection, identify potential bottlenecks or issues, and make informed decisions about network iperf is a tool for performing network throughput measurements. The options of -d or --dualtest will provide two sockets (but won't pierce a NAT firewall so one has to either remove it or configure port forwarding. 5Gbe connection from the same pc I get 2500 Mbps down and up via libre. Client-Side: Basic default test: iperf3 -c 10. 3 Mbits/sec ' 5' 0. ) Out of Order = 1 datagram. This version, sometimes referred to as iperf3, is a redesign of an Run the command “iperf –s” in the DOS page, then the EAP will work in the iPerf server mode. Step 4. And Iperf gets 2. Summary. iperf -s. Then, on another device run iperf3 -t 60 -c . $ iperf -s. It shows how to install on Unraid, Windows, macOS and Linux. C:PathTo>iperf3. Aug 6, 2014 · I am trying to start an iPerf server (its a program similar to ping), and pipe its output to a . Let's take a LAN-to-LAN speed test, for example. Your file in directory c:\iperf3\text. Other factors that may impact the transfer rates for data sets comprised of small files include the application of access-control lists (ACLs), the number of tasks vying for disk space, and the number of errors generated and logged. 100 -i 5 -t 60. Normally, the test data is sent from the client to the server, and mea-sures the upload speed of the client. Now, when Testing via a 2. It's also available for Mac and Windows. "which is odd" when Testing cd mark to the Nas I get 180 MBps read and 165 MBps write. Initiate the client by using the following command. We recommend using nuttcp or iperf3 for high-speed UDP testing. Test the speed between the EAP and your wireless client. In the command prompt on the server side, run this command. Installing iPerf on Client and Server. Windows. It supports tuning of various parameters related to timing, protocols, and buffers. By default, the test runs for 10 secs but can be changed with the -t option. This sets the server into UDP mode with an interval of 1 sec. sudo apt-get install iperf. Once it's installed, you need two machines on the same network to use it (both must have iPerf installed). Click the file you want to download to start the download process. Start downloading a large file from the Internet to your computer (use a file between 1 and 2 GB; it can be a video file, iso image, zip archive, etc. Of course, there are Iperf versions for UNIX, Linux, BSD, MAC OS X, and Solaris. CloudFlare CDN: This speed test is hosted on the CloudFlare CDN. 7Mbits/sec. Jul 8, 2019 · iPerf UDP Client and Server. Now under the selected device, click create graph for the device. 6 -i 1 -t 30 Jan 6, 2018 · How to use Iperf to test 10Gbps network bandwidth The big advantage and main reason why we use Iperf is, that it is capable of running multiple test connections between two servers simultaneously. vi lu wd fm wf zr lg av eg fj