Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [iperf]

For questions about the open-source software Iperf, where it is a widely used tool for network performance measurement and tuning. Remember that only questions in relation to on topic network devices are allowed.

0
votes
1answer
31 views

Why is there a difference on the amount of data transferred during a UDP iperf measurement?

I have the following result from a UDP throughput test as measured by iperf3 $ iperf3 -u -t 10 -c 192.168.1.2 -b 100M -V iperf 3.6+ Linux pi-raspberry1 4.4.38-v7+ #938 SMP Thu Dec 15 15:22:21 GMT ...
0
votes
1answer
377 views

Iperf connection refused using mininet [closed]

I have created a topology using below command and using POX as a remote controller. sudo mn --switch=ovs --link tc,bw=10 --topo=tree,depth=2,fanout=2 This creates a topology with 1 controller, 3 ...
1
vote
1answer
64 views

IPoIB with Netem (Latency emulation) Poor performance

I have to emulate a wide area network. My setup contains two servers with MT27500 Family [ConnectX-3] Infiniband cards. Default latency between both nodes is ~0.4ms and iperf test shows throughput of ...
0
votes
1answer
44 views

Definition of bandwidth capacity for an internet connection

First, I want to test the data rate of a fibre-optic internet connection, but I understand that results are affected by the circumstances of the test, like number of hops between the CPE and the other ...
2
votes
1answer
195 views

cisco catalyst 3560 rate-limit on vlan is not observable with iperf

I have a dumbbell topology with two hosts and two switches. Host1 is connected to Switch1, Switch1 is connected to Switch2, and Switch2 is connected to Host2. To make things more interesting Host1 ...
1
vote
1answer
210 views

How can I find bottlenecks using IPERF3?

I've just started using IPERF and I'm rather confused about the results I'm getting. When IPERF reports bandwidth does it actually mean throughput as when repeating tests the values returned seem to ...
0
votes
0answers
24 views

Jain's fairness index in multirate wifi networks

when you have different data rates in a network, how can you use the Jain's fairness index to compare the network fairness. In some papers the throughput is normalized. What is this normalizing ...
0
votes
1answer
2k views

iperf: send specific volume?

I wanted to test some different test cases. I wanted to transmit 1MB, 10MB, 100MB, ..., 1GB, ... and measure bandwith with iperf. In the manual stands that I can use a combination of -l and -n ...
1
vote
1answer
351 views

Calculating the Jain Fairness Index of two connections - what values to use?

I'm using GNS3 and I have 3 VMs. I established two simultaneous TCP connections to an iperf server I created on VM2. VM-1 -- VM-2 VM-3 -- VM-2 Using the iperf -c <IP of VM2> command, I ...
0
votes
1answer
2k views

Iperf results on UDP Bandwidth

I am currently testing iperf with a view to automating some testing servers for our company. To do this I am using an iperf server in the cloud which is well connected and is only 5 hops away from ...
1
vote
1answer
99 views

Why I don't see drops with a TCP flows in Linux

I wanted to observe the congestion window of a TCP flow so for that I have to nodes (using Linux namespaces) connected to each other through veth pairs and a bridge. To limit bandwidth to 10mbps I ...
5
votes
2answers
787 views

WiFi TCP iperf throughput: upstream vs down stream

In a WLAN iperf3 TCP throughput test, I have the following results: With exactly the same setting, operation in 802.11ac (3x3) (DFS channel) (TCP Cubic) 30 nodes as server receiving iperf -> ...
0
votes
1answer
231 views

Test VPN tunnels with multiple source.

We have a lab setup to test VPN tunnels. I am checking for any way by which we can simulate traffic from multiple source to the vpn to test the traffic. We tried iperf but it shows result only for a ...
0
votes
1answer
841 views

Use iperf to split multiple tcp streams between 2 NIC on same client (similar to IxChariot)

I have 2 PCs connected to each other using two 1 Gbps ethernet link, to have an aggregate data bandwidth of 2 Gbps. In IxChariot, I can create multiple TCP pairs and split them into: PC1_LAN1 <-&...
3
votes
2answers
935 views

IPERF TCP vs UDP

I had to determine UDP performance over multi-hop network , I used MAC Air over gigabit ethernet ( Thunderbolt). As is customary, TCP was tested and the gig over link was saturated ~900mbps, but ...
1
vote
1answer
639 views

How to verify that the connection is 10G? [closed]

I have 2 servers connected with 10G cable between them directly. I need to know that the connection is good and it has indeed 10G throughput. I used IPERF to verify the bandwidth. According to the ...
0
votes
3answers
815 views

What iperf flags should I use to test link LACP bond total speed

I have created an channel group with LACP, I know that single TCP session will be sent over a single line. My hashing algorithm is set to source mac address. So how can I be sure that the bandwidths ...
0
votes
4answers
4k views

Lower throughput with fixed TCP window size?

I used iperf3 to measure the effect that the TCP window has on throughput. I am measuring the throughput between two virtual machines which are located on different physical hosts. So I wrote a Python ...
3
votes
2answers
2k views

Where are UDP packets lost during iPerf test?

I'm testing a 802.11 wireless link using iPerf and the UDP protocol. Using the -b command at the client, I can set the bandwidth to an arbitrary number (e.g. 1 Gbps) that's much higher than the link ...
0
votes
1answer
2k views

GNS3: performance tests using iperf3? [duplicate]

I'm running some performance tests on GNS3 (I know I shouldn't, but it is not until Friday that I will have the college lab available), and I'm trying to compare real BW or "speed" and theoritecal. ...
2
votes
3answers
199 views

There's huge gap between two results for iperf

I used iperf -c FOO_NODE -t 120 -i 10 to test the network with the other node FOO_NODE, sometimes I get the result like: [ ID] Interval Transfer Bandwidth [ 3] 0.0-10.0 sec 3.75 MBytes ...
0
votes
6answers
9k views

VOIP testing with IPERF tool

Does iperf support VOIP? If yes! then please tell me what are the commands for testing voip and video streaming.
3
votes
4answers
10k views

Iperf 'set bandwidth' command issues

I am unable to set the bandwidth on both sides using the Iperf tool. When I use the command iperf -c 192.168.1.15 -b 10m -l 32k -w 128k I get this error: --iperf: ignoring extra argument -- 10m --...
0
votes
1answer
261 views

Tuning UDP-lite protocol instead of UDP with “IPERF” tool

How do i test network connection for UDP-Lite protocol (along with checksum coverage) instead of UDP with "IPerf" tool. for udp we use following command-> iperf -s -u -i 1 what command should i ...
3
votes
1answer
3k views

standard results for gigabit ethernet iperf

I can't achieve good transfer rate through scp and I wonder if the network configuration isn't tuned up correctly. I've noticed some differences when running iperf through tcp vs udp. Are these ...
1
vote
1answer
566 views

Why don't I see client-to-server TCP traffic when sniffing iPerf TCP throughput?

When I do an Omnipeek capture of an iPerf TCP throughput test over WiFi, I only see TCP Acks from the iPerf server to the client. How come I don't see any TCP frames from the client to the server? I ...
12
votes
3answers
19k views

Wifi TCP iperf throughput: 1 stream vs multiple streams?

In a WLAN iperf TCP throughput test, multiple parallel streams will give me higher throughput than 1 stream. I tried increasing the TCP window size, but I still cannot achieve the max throughput with ...