Iperf Server Command

Run Iperf on one system in server mode (-s) and on another in client mode (-c) and within seconds it starts spitting out nice reports on bandwidth, jitter, and loss. By default, iPerf runs for 10 seconds. net -r -P 4. Iperf is a command line-only tool that is used to diagnose network speed issues. Hoping not too many people will reply and that one or two can explain this. The way iperf works is that you install iperf executable on all the machines that you want to test and you run one machine as a server and rest as a client. To perform an iperf test the user must establish both a server and a client. xxx -w 300k -t 100 -i 10" and Enter on command line as a picture. There are several ISP's involved from Helsinki to London(5 if my Iperf test uses the same path as my traceroute ). " This tool has to configure server side and client side to complete a test. iperf -s -D > iperflog. 0 KB (default)-----This runs iPerf in server mode and will wait to accept the client's connection. iPerf is a nice tool for that. While the Intel Ethernet Server Adapter XL710 performed better than the 10 Gb NICs, it performed at roughly 70 percent line rate when the iperf server ran on the VM, and at roughly 40 percent line-rate. A list of public iperf servers can be found here: https://iperf. iPerf is good free open source tool when there isn't really a need to use commercial more expensive tools. NET would be ideal for this, setting up a 'listener' on one machine, then a 'client' on another and trying to max. in this way iperf will listen as a service on the default port, the 5201:. Unlike NetPerf, when using Iperf we need to configure both client and server sides. sudo apt-get install iperf – on server side: iperf -s – on client side: iperf -c IPADDRESS -f k. Iperf server. From the managed switch some testing was performed using an iPerf server and client. One key reason we purchase MT products is because they provide so many diagnostic features. Lets test the throughput from the Linux client machine, as shown below. I'm trying to do network testing using iperf or netperf tools, and I'd like to be able to run both the client and server on the same computer. Combining psexec and iperf for CLI measuring LAN bandwidth. iPerf is an open source tool for measuring throughput between two network nodes and has been compiled for Windows. the cript would be run from multiple IPERF Client servers to a single IPERF Server. Jperf can be associated with Iperf to provide a graphical frontend written in Java. Previous message: [mininet-discuss] Running iperf commands on hosts created in mininet Next message: [mininet-discuss] Random MAC Address seen in the packet received. 13a so it's a good time to add the multiple group join if it's useful. Example of iperf client command syntax in iperf 3. airstreamcomm. It is the industry standard tool for checking the interface and uplink and port speeds that IaaS providers (aka Cloud companies like IBM Softlayer, Rackspace, AWS) advertise. This group includes Process, Threads, Kernel and User Image Load/Unload, Disk I/O, DPCs and Context Switch events. To install the iperf tool, you first need to install the EPEL repository. Logon on to DDOS by ssh and run the following command: # net iperf server run. After noting disparities between upload and download rate, I wanted to use the -d option and stumbled on a weird behaviour: although the transfer went through in the client to server direction, in the other direction it freezed and didn't seem to tiemout. In this example, we will run the iPerf client on VM1 and the iPerf server on VM2. Iperf reports bandwidth, delay jitter, datagram loss. Also on most OSes using this option will also respond to IPv4 clients using IPv4 mapped addresses. If passed through the client command, the outgoing interface will be set. Note on computers running Win7 or Win2008 I recommend running the cmd prompt in elevated mode. yum install iperf --enablerepo=dag and for the future if you are looking some rpm but you are not sure where it is or in which repo try (i was looking for iperf for you like this) Code: [Select]. Connect to your nuc via ssh and start iperf as a server : 'iperf' is not recognized as an internal or external command, operable. The client pushes traffic through the network while the server receives the data and measures statistics. More on Docker commands can be found here. net -r -P 4. net runs a TCP Iperf server on the default port 5001; iperf. Run the following command on the Iperf server. One host must be set as client, the other one as server. 100, then enter: iperf – c 192. Iperf has many configurable options for testing network throughput. Running the server as a daemon Use the -D command line option to run the server as a daemon. This fixes a: 61 regression introduced in iperf-3. Host1 has the iperf server, listening on port 5002, Host2 is the client. One side runs in a "server" mode, listening for requests; the other end runs "client" mode, sending data. Before running a test you will need to make of the hosts the iperf server. The basic commands are the same for iperf and iperf3: SAMPLE IPERF/IPERF3 COMMANDS Server: iperf/iperf3 -s Start server on the default port iperf -s -w 32M -D / iperf3 -s -D Start server with larger TCP window, and in daemon mode. iperf will run on any Linux or Unix (including Mac OSX), and must be installed on both hosts. If Zephyr acts as a client, iPerf must be executed in server mode. Run the following command on the Iperf client and wait for. The -d and -r Iperf client arguments measure the bi-directional bandwidths. TCP server:. More on Docker commands can be found here. On the recieve (server) side you can run a single iperf instances that will bind to all interfaces (this is the normal 'iperf -s' behavior), or exec multiple iperf servers, each using -B to bind to a specific interface (for finer-grained logging and control) as pileofrogs mentioned. Example of iperf client command syntax in iperf 3. 1 Test Bed: Server 1 is an iperf Server and Server 2 is an iperf Client. 5 (released July 8, 2010) • No further development, maintenance only - critical patches - sporadic releases, only when necessary Iperf 3 • Currently in development • Current version is 3. 2(HTTP Server) to start listening on port 80. This will have the iPerf Server running as a daemon and the server messages will be logged in the file iperfLog. One side is the client and one side is the server the, the -w switch is to set the TCP receive window size for the purpose of this discussion its 64KB Here are the commands you need to get started, from the server side you only need a few commands these are below. Iperf is designed to measure the throughput between two points and runs as a client/server pair. Performs a TCP upload from the client and server. After downloading iPerf: 1. /configure # make # make install # cd src. Testing bandwidth between 2 hosts can be helpful to determine maximum transfer rates, and how much bandwidth can be pushed. Use Ctrl+C to stop the server once the data has displayed. It does assume the client and server clocks are synched with something like.  It can test either TCP or UDP throughput. User Manuals IPERF(1) NAME iperf - perform network throughput tests SYNOPSIS iperf -s [ options ] iperf -c server [ options ] iperf -u -s [ options ] iperf -u -c server [ options ] DESCRIPTION iperf is a tool for performing network throughput measure- ments. In my examples I'm using 192. I did the above and performance is still low, what should I do now? Enter command top then hit ’1′, see the CPU utilization of each core; if any of the cores is above 90% utilized then that can be the bottleneck. (iperf command is available). To confuse things, there's an iperf2 and an iperf3. How are you opening it? There is a possibilty that you have the following Registry setting configured:. Download this app from Microsoft Store for Windows 10 Mobile. A key point to remember when testing bandwidth with Iperf is that Iperf consumes all bandwidth available between client/server via TCP, regardless of LAN, WAN, or VPN connection. Default Iperf settings: By default, the Iperf client connects to the Iperf server on the TCP port 5001 and the bandwidth displayed by Iperf is the bandwidth from the client to the server. To perform an iperf test the user must establish both a server (to discard traffic) and a client (to generate traffic). Download this app from Microsoft Store for Windows 10 Mobile. If you don’t have an IP address of a suitable Iperf listening server, please contact our support and we will provide you with one. 6 versions do. Feb 17th, 2015 8:30 AM EST. How to Test the Speed of Your Home Network with Iperf. Performs a TCP upload then download between the client and server. iPerf on Windows uses the old-school, one-letter parameters because it is an EXE. Iperf through router with NAT. This will be our client and we are telling Iperf the server is located at 192. Daemon mode is used when you want to keep your iPerf Server up and running without having to SSH in each time to start it up. GENERAL OPTIONS. com/esnet/iperf; Install the App. The optional –f M flag tells iperf to report its statistics in Megabytes. Iperf was orginally developed by NLANR/DAST as a modern alternative for measuring maximum TCP and UDP bandwidth performance. Noted : mail. To perform an iperf test the user must establish both a server (to discard traffic) and a client (to generate traffic). To run an Iperf test you need two RPis: one to act as a client and one to act as a server. 15 -b 10m -l 32k -w 128k I get this error: --iperf: ignoring extra argument -- 10m. Handy iperf commands for quick network testing. What is iPerf / iPerf3 ? iPerf3 is a tool for active measurements of the maximum achievable bandwidth on IP networks. - Log will be \My Documents\btools_log. Because of its long history and many iterations, I have always found it a little confusing to get started with. Measure network performance with Iperf/JPerf 802. Running iperf -s will setup a basic Iperf server, you can also run Iperf in daemon mode by running iperf -D. HOME LOGIN Linux References & Commands Linux Versions & Patch Linux Startup and Shutdown Linux Software Installation Linux Network-Based Installation Linux Syslog & Logrotate Linux Kernel Confiugration & Tuning Linux Disk & File Systems Linux Advanced Disk Access & Management Linux Samba: Sharing Resources with Windows Linux User Interface. Is the Ubiquiti speed test broken? I can only get it working with iPerf on a PC with legacy gear like bullets. iperf3 is a free open source, cross-platform command line based program for performing real time network throughput measurements. The way iperf works is that you install iperf executable on all the machines that you want to test and you run one machine as a server and rest as a client. run() finishes and produces the test results. It's open source and cross platform supports variety of operating system including Microsoft window, Linus, UNIX, Apple Etc. The Server or the Client can be linux or windows. In the command prompt on the server side, run this command. Lets test the throughput from the Linux client machine, as shown below:. It has been around for many years and has undergone some major updates along the way. name being the server that you are testing to. Iperf does a great job of showing how much bandwidth it can push through the link between server and client, as well as delay and jitter of the UDP session. It supports tuning of various parameters related to timing, buffers and protocols (TCP, UDP, SCTP with IPv4 and IPv6). I initiated a iperf TCP client|server for 90 sec and observed throughput was 11Mbits/sec With UDP its just 1. 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. The output format is determined by the server (in particular, if the server was invoked with the --json flag, the output will be in JSON format, otherwise it will be in human-readable format). iperf -c -F 500MB_Test_File. It is significant as a cross-platform tool that can produce standardized performance measurements for any network. 3 to connect to the server on the AP. i never mentioned having pfsense at each end. Legal Notices and Terms of Use. Start a listener service on port 5201 and name the container "iperf3-server" (if the image is not yet downloaded, the run command will pull it down for you). The traffic goes through a VPN from customer network to our network. Daemon mode is used when you want to keep your iPerf Server up and running without having to SSH in each time to start it up. # server port to listen on/connect to Most other options can be set by an environment variable IPERF_The Fiber Backpack is an SFP-to-Ethernet media converter designed specifically to be co-installed with H510 APs to extend H510's reach into Hotel and MDU deployments where Fiber is being installed for backhaul (instead of copper-based Ethernet). 10:6969 and prints out the test results. I needed a task which would wake up my PC (if needed) and started an iperf server. Generating Traffic With Iperf Basic Usage. You can do so by running the following command on the ESXi Shell:. the IPerf command line? You will need to do the same thing on the client machine, starting with identifying the machine as the client. Test Case without QoS Configured. The basic commands are the same for iperf and iperf3: SAMPLE IPERF/IPERF3 COMMANDS Server: iperf/iperf3 -s Start server on the default port iperf -s -w 32M -D / iperf3 -s -D Start server with larger TCP window, and in daemon mode. Spread the love Iperf: Iperf is an open source networking tool used to measure throughput or performance of a network. Download iperf; Extract the downloaded folder to C:\Temp\iperf-3. For more information on how to use the Ekahau Throughput Server, please refer to Ekahau Throughput Server documentation page. Then, on one of the nodes, start the iperf server using the following command: shell> iperf -s. iperf vs iperf3 from wikipedia. What is iPerf / iPerf3 ? iPerf3 is a tool for active measurements of the maximum achievable bandwidth on IP networks. between Server 3 & Server 4. Once you run the command in the router, it will be there until you reboot. So do that we will install the latest. 04 (Xenial Xerus) Install iperf Installing iperf package on Ubuntu 16. This is helpful to know which IP Address to bind to the iperf3. Noted : mail. To test throughput, you will need two PCs acting as network nodes connected to the wireless network: one running iPerf in server mode and the other running. Introduction The FCSDK in HA mode will use multicast & jgroups to share state. 0b1 (released July 8, 2010) • Weekly beta releases (starting this past Thursday). rizkypratama. The iperf utility is a great option for this. Strangely, until recently I had completely missed JPerf utility that equips Iperf with graphical interface to escape horrors of command line setup. For any Android device you can install iperf application from Play Store for free 🙂 & then you can run these iperf client server commands. When I use the command iperf -c 192. id merupakan server yang akan saya test bandwidth dari sisi saya, silakan diganti dengan keinginan anda. You can run the command iperf -help to list the specific parameters. yaml You can verify the output from the server: kubectl logs -l app=iperf-overlay-server and the client Job:. I need a good layman understanding of Iperf testing. Full documentation can be found at the iperf documentation page. Select 1 of the Public iperf Server; to test the Internet Throughtput. You can find out various settings and options for iperf by typing iperf –h. It will to join multicast group 239. Try server to server via a single 10Gb link. 94MBytes, Bandwidth=1. Use these scripts to start iperf as a client or server. The -P parameter is used to execute ten worker threads to fully fill the available bandwidth. This tutorials will teach you the way to use the iperf command line to determine various parameters of link. iPerf is a command-line tool used in diagnosing network speed issues by measuring the maximum network throughput a server can handle. iPerf is a network bandwidth throughput testing software. Mainly, we use iperf on TCP connection to measure the TCP throughput (Part B), which will lead to calculate the TCP window size. Link Capacity: 1. Using Iperf commands on the client-server (in this case your server), you will run a benchmark test and show the throughput data of all test connections. In order to send a single UDP stream from n2p2 to n1p2 as shown in Fig. JPerf stands for Java Perf; it’s a GUI for running iPerf without having to bother learning the Command Line Interface (CLI) options. 0) - In PC, open console box and run "iperf -s" - In Mobile, Choose iperf client tab and type server's IP Press "Start" - iperf will run 10 seconds if -t option is not specified. Of course, you can get more sophisticated with your testing at this point, but I keep it simple for most cases unless something unusual pops up. You will need 2 computers on the same network, and the IP Address of one of them. iperf3 is a complete rewrite of the original iperf - Client and Server classes around iperf3's libiperf. The server has limited connection access. airstreamcomm. In other words, when doing an online speed test, you connect to a server on the Internet, owned by the provider of the test (like Ookla). If you are not sure if the traffic that you wish to test is UDP or TCP, run this command to determine which services are running on the FreeNAS® system:. Download this app from Microsoft Store for Windows 10 Mobile. You can use -p option for limitting the incoming clients. Iperf is available for Windows, Arch Linux, Ubuntu, Android, iOS, and more. net), you do not need to install your own server. the number on the iperf client and iperf server are very close. TCP server:. The directory listing is done with the Is command. Input "iperf -c - t 6000&". route add -host 239. Client download test. Iperf is a tool to measure the bandwidth and the quality of a network link. --get-server-output Get the output from the server. So do that we will install the latest. The network link is delimited by two hosts running Iperf. And also have a local device, which is use to test the throughput between local and remote server. Open a command prompt and navigate to the folder containing the iperf3. $ iperf -c iperf. Par défaut le test réseau se fait en utilsant le protocole TCP (mais il est également possible d'utiliser le mode UDP avec l'option -u). Generating Traffic With Iperf Basic Usage We give an overview of some of the basic features of iperf which is a traffic generation tool that allows the user to experiment with different TCP and UDP parameters to see how they affect network performance. In such case results we got during the test:. Use these scripts to start iperf as a client or server. For iOS device you have to pay ;(Like this I have run this performance testing for all those clients mentioned & export that data onto excel. Using the same example, you could use -w values of 1. 3 to connect to the server on the AP. x, you need to look at the server side output as it is generated there. Iperf 2 GUI as a server and Iperf 3 command line as a client). One host must be set as client, the other one as server. We can use man iperf command in Linux to get all arguments. And also have a local device, which is use to test the throughput between local and remote server. Iperf 2 • Iperf 2 is widely used • Current version is 2. The same iperf binary can be used to run the process in server and client modes. Iperf commands: There are many arguments for Iperf command, we will discuss on only important and useful arguments. If passed through the client command, the outgoing interface will be set. It supports tuning of various parameters related to timing, buffers and protocols (TCP, UDP, SCTP with IPv4 and IPv6). If all goes well, we should see RSS in action on the iPerf server. Iperf was one of the earliest apps covered at this blog (second only to Opera) and I still happily use it. The -P parameter runs ten worker threads to push the performance test to the max. Mainly, we use iperf on TCP connection to measure the TCP throughput (Part B), which will lead to calculate the TCP window size. First, remove the container which is mapped to port 5001 docker rm -f mapped-iperf. The latest version of iperf3 now supports disk to disk testing. Check IPERF command-syntax when client is seeing “WARNING” without “connection refused” and the other person (acting as server) is seeing nothing. Then, select one machine to be the server and record the IP address. In order to send a single UDP stream from n2p2 to n1p2 as shown in Fig. Whoever is seeing “Connection refused” on their screen needs to tell the other person to take a look at their port-forwarding and computer-firewall configuration. If network speed is limited during normal operation so will the SLP replication. When using Iperf to test the speed, we need to set one PC as a server and another PC as a client, in this FAQ we set PC A as server and PC B as a client. After inputting this command, then click Enter to start measuring the speed. 3 ethX (where X is the interface number used to transmit/receive multicast traffic) Run the command shown below. One side runs in a "server" mode, listening for requests; the other end runs "client" mode, sending data. Install iPerf on both servers. , the iPerf output included below is from a test to a publicly available iPerf server, bouygues. 0 API - Documentation on readthedocs. From the managed switch some testing was performed using an iPerf server and client. Note: The utility uses port 5201 for a connection. Running iPerf Server in Daemon Mode. You should notice different results on the output. Link Capacity: 1. 5 (released July 8, 2010) • No further development, maintenance only - critical patches - sporadic releases, only when necessary Iperf 3 • Currently in development • Current version is 3. The Iperf tool is a freeware that can be run as executable file either in server or client mode. It is a highly reliable tool in comparison to the many network bandwidth and speed testing tools. Test your server's bandwidth. to start in server mode (the listener) you would type iperf -s. 9sec, Transfer=1. Common used command –-i :record time on the CLI (Ex. Although iperf3 has a GUI of sorts the traditional way to run iperf is from the command line. try using the -p 5000 option or just specify 5000 after the hostname. You do not have permission to edit this page, for the following reason:. net -r -P 4. Install iperf on both pfsense. It can test either TCP or UDP throughput. About the App. iperf is a tool for performing network throughput measurements. Iperf, or its latest incarnation, iperf3, is a client/server tool. Experiment is repeatable if:. Use iperf for quick and easy network tests. Iperf looks at how fast your car can go down that route, pure speed, in real numbers. This sets both send and receive buffer size. Using Iperf commands on the client-server (in this case your server), you will run a benchmark test and show the throughput data of all test connections. The test is over UDP. This package contains the command line utility. Performs a TCP upload from the client and server. Lab 2: Iperf Command Objectives Being familiar with the command iperf. Measuring network throughput with Iperf Iperf is a command-line tool that can be used to diagnose network speed related issues, or just simply determine the available network throughput. Step 2: Test The Network Speed Between Two Windows hosts. Which points out to the possible problem with the 10G network cards. Download this app from Microsoft Store for Windows 10 Mobile. To test RSS, i have 2 VM’s running iPerf. Usually iperf client send data to iperf server, what I need in this case is the server send data back to the client in the same connection. Trial version operates upto 10Mbps and 2 threads, without QoS. 3 ethX (where X is the interface number used to transmit/receive multicast traffic) Run the command shown below. The only way I found to fix this issue was to basically copy the iPerf binary to another file like iperf. 3 to connect to the server on the AP. 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. In addition, you need to setup iperf to run on 2 machines: the 'client' and the 'server'. Performs a TCP upload then download between the client and server. Once again, my question was how to test from pfsense to client antenna. LibreELEC Forum. in UDP mode, the client will send almost 100% traffic to server side. iperf3: interrupt - the server has terminated BTW, I think non-zero receiver statistic is a bug - as iPerf client, Fortigate will act as a sender, not receiver. This app is an iOS port for iperf3, which is the most commonly used network testing and performance computation tool. iperf -s -D > iperflog. try using the -p 5000 option or just specify 5000 after the hostname. In such case results we got during the test:. Iperf is a traffic generation tool that allows the user to experiment with different TCP and UDP parameters to see how they affect network performance. Although Iperf’s command line interface is relatively easy to use, there’s also an OS X port with a GUI. psexec is very good command line utility from Sysinternals that allows to execute remote commands on network computers (if you have security rights to do so). It supports tuning of various parameters related to timing, buffers and protocols (TCP, UDP, SCTP with IPv4 and IPv6). Redirect the output to a file. The commonly used option with Iperf for RHA are as below:--s Start as server ( Always on the Master )-c start as client ( Always on the Replica)-w Window size ( TCPSendRecieve Window size in RHA)-l Buffer ( Chunklentgh in RHA)-p specificy number of multiple connections ( Streams in RHA). Default Iperf settings: By default, the Iperf client connects to the Iperf server on the TCP port 5001 and the bandwidth displayed by Iperf is the bandwidth from the client to the server. First, remove the container which is mapped to port 5001 docker rm -f mapped-iperf. Iperf is a modern alternative for measuring TCP and UDP bandwidth performance, allowing the tuning of various parameters and characteristics. The presentation changes directories as Downloads bash shown. iPerf is a widely used tool for network performance measurement and tuning. In the log file, you will find the send and receive time of the packets, subtract them and you get the 'delay'. The directory listing is done with the Is command. If the connection is successful, the iperf log should be able to be seen in the linux machine terminal. iperf is a free and open source network testing utility that allows you to measure the speed of IP networks. iperf3 --server. 5-2-win32 tool to find network bandwidth. To send traffic in the reverse direction use the -R flag ex: iperf3 -c iperf. To perform an iperf test the user must establish both a server (to discard traffic) and a client (to generate traffic). Only the port 5002 is opened to the outside. We give an overview of some of its basic features here. The iperf code in WICED appears to be based on 2. the IPerf command line? You will need to do the same thing on the client machine, starting with identifying the machine as the client. Using iperf on a Microsoft Windows system Iperf is a free open-source software tool that provides a capability to measure the throughput between two hosts using both Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) data streams. A key point to remember when testing bandwidth with Iperf is that Iperf consumes all bandwidth available between client/server via TCP, regardless of LAN, WAN, or VPN connection. Due to "iperf" is command-line, we can add a graphical frontend tool "Jperf" or "XJperf" (develop on Google Code) after the "iperf" is installed so that the operation will be easy. I run iperf on a server in server mode, and on a MacBook as the client, and then reverse the roles to test the other direction. It will run in the background just waiting for connections from iPerf Clients. The commonly used iPerf commands are listed in the following table. When he launched the second pair of iperf Client - Server, total aggregated bandwidth was still around 3 Gbits/sec. - Log will be \My Documents\btools_log. The newer versions of iperf need this to fully stress the connection. Install iPerf on both servers. With iperf installed, we need to start its server mode on one of the hosts. on server: iperf -s <--at server side, it will listen on port 5001. iperf works in a client/server model: one iperf command is run on one server in server mode, one iperf command is launched on another server in client mode. Usually iperf client send data to iperf server, what I need in this case is the server send data back to the client in the same connection. in this way iperf will listen as a service on the default port, the 5201:. This is helpful to know which IP Address to bind to the iperf3. 04 and iperf 2. I did the above and performance is still low, what should I do now? Enter command top then hit ’1′, see the CPU utilization of each core; if any of the cores is above 90% utilized then that can be the bottleneck. You can find two very good tutorials here and here that provide an introduction on Iperf and all of its command-line options. In my examples I'm using 192. Install Iperf and Test Network Throughput,Speed/Other Statistics September 19, 2014 Updated September 19, 2014 LINUX HOWTO , MONITORING Iperf is a network testing tool that can create TCP and UDP data connections and measure the throughput of a network that is carrying them. iperf running on pfSense® software is NOT a suitable way of testing firewall throughput, as there is a significant difference between performance of traffic initiated or terminated on the firewall and traffic traversing the firewall. Features: * Measure bandwidth, packet loss, delay jitter * Report MSS/MTU size and observed read sizes. The –s flag tells iperf to run in server mode. All Answers ( 3) Those are available at the server, either run-time or by reading the log the server generates. Specifies the command to use to connect to the server. We’ll setting up 1 iperf client and 1 iperf server. Open command prompt in the folder path where this executable file is located.  To perform an iperf test the user must establish both a server (to discard traffic) and a client (to generate traffic).