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Questions tagged [iperf]

Iperf is a network testing tool for performance and tuning that can create TCP and UDP data streams and measure the throughput of a network that is carrying them.

Iperf is a network testing tool for performance and tuning that can create TCP and UDP data streams and measure the throughput of a network that is carrying them.

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Why do iperf3 and tcp_probe report different congestion windows?

I am running a simple experiment with multiple iperf3 senders on different servers, sending TCP traffic to a single receiver on another server. iperf3 reports the congestion window (Cwnd) every 0.1 seconds during this experiment (in KBytes). I also…
aousterh
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Why are packet drops in UDP correlated with number of packets vs. bandwidth utilization

I'm testing the speed between a client and host using iperf. In my application, I need to be able to send 2 byte UDP frames at roughly 5KHz. Doing a normal UDP speed test I can easily get 10Mb/s: $iperf -uVc some_ip -b 10M Interval Transfer …
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How do I get bandwidth and received signal strength information using Java?

I'm on a Windows machine using Java. I would like to get my bandwidth and received signal strength (RSSI) readings. On my Mac, I use the iperf and tcpdump utilities respectively. 1) I can't seem to get RSS readings from winpdump 2) I'm not sure how…
user
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Iperf under Cygwin not recognizing arguments

I'm running Cygwin on Windows 7 and trying to run Iperf 2.0.5-2 with it. For some reason, any arguments passed to it seem to be ignored. For example, ./iperf.exe --help or ./iperf.exe -s simply output usage instructions. (Same as the output from…
iank
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why does delay decrease when running iperf with udp?

I am trying to show how queueing effects delay over time so I am pinging my destination from my source while sending iperf udp traffic from the source to destination. But I noticed that the delay I am seeing from the ping immediately decreases for…
user3344882
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Why low data throughput is observed when iperf tried with UDP packet size set below 2000?

I'm experimenting on an LTE connection for checking the maximum rate of bandwidth can be achieved in the uplink.While creating iperf sessions i observed that i'm not able to go beyond 100Kbps in the uplink when the UDP packet size is set as…
Renold Singh
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Interpret iperf TCP bidirectional measurment

I have measured my wlan connection on embedded system with iperf. I get speed difference in both directions. I do not know how can I interpret it, and if it is something to fix. Test setup: Embedded Platform with USB wlan stick…
Bartlomiej Grzeskowiak
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Does iperf have a bandwidth ceiling?

I am trying to run iperf and have a throughput of 1Gig. I'm using UDP so I expect the overhead to pretty much be minimal. Still, I see it capped at 600M despite my attempts. I have been running: iperf -c 172.31.1.1 -u -b 500M -l 1100 iperf -c…
WildBill
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Capturing certain value from iperf result using grep

I use iperf3 version and then I get the performance result like this in terminal : [ 4] local 10.0.1.8 port 34355 connected to 10.0.1.1 port 5201 49,49,0,0,35500 [ ID] Interval Transfer Bandwidth Retr Cwnd [ 4] 0.00-1.00 …
bnbfreak
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Capturing / calculating real time TCP delay / RTT using iperf or similar tools

I want to ask, how to capture or check TCP delay / RTT every time using iperf? because I only see UDP delay jitter capture in iperf. If iperf can't capture that, is there any tools to capture real time TCP delay/RTT? Thank you
bnbfreak
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The average Jitter calculated in Iperf

In the RFC 1889 the delay jitter is given by J=J+(|(Rj-Sj)-(Ri-Si)|-J)/16 I use iperf to measure delay jitters between two network nodes. I got [ 3] 0.0- 1.0 sec 18.7 KBytes 153 Kbits/sec 8.848 ms 0/ 13 (0%) [ 3] 1.0- 2.0 sec 15.8…
Dan
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Export & Map CSV output to MySQL table using Python

I have a multiple clients to single server bidirectional iperf set-up for network monitoring. The iperf server runs well and displays output in CSV format based on the cron jobs written on the client end. I wish to write a python script to…
shyene88
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iperf UDP server start error, bind failed: Operation not permitted

OS : Windows 8, Tool : Jperf, internal Tool : iperf i want to start UDP Server listener. Command Used:- iperf -s -u -P 0 -i 1 -p 5001 -l 1470 -f k -t 10 Server listening on UDP port 5001 Receiving 1470 byte datagrams UDP buffer size: 64.0 KByte…
VISHAL VIRADIA
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Meaning of iperf TCP bandwidth of 24 Gbps on a Gigabit ethernet controller

I am using ubuntu and have a JMC250 PCI Express Gigabit Ethernet Controller. I used iperf with TCP on localhost and it gave me a bandwidth of 24.2 Gbps. What is the meaning of this bandwidth? I did this test on localhost assuming it will come out…
AzureMinotaur
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iperf server on windows using python

This may not necessarily be a Python related issue but I'm hoping someone can point me in the right direction. I'm trying to start an iperf3 server on a Windows system using Python. In my code I have import subprocess iperfserver =…
MightyMouseZ
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