esnet/iperf

Mismatch between sent and received data size

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#382 opened on Mar 10, 2016

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Help Wantedbugbug:test-data

Description

I'm running iPerf 3.1.2 on 2 Ubuntu 14.04 machines.

If I run "iperf3 -c xx.xx.xx.xx -n 1M" because I only want to send around 1MB of data, on the receiver end, only around 350KB is received.

When I use wireshark to capture the packets, I can see that after around 350KB of data is received, the receiver (i.e., iperf server) sends a TCP RST to the sender and refuses to accept more data.

Is there some reason that iPerf behave this way? (maybe I missed something)

Contributor guide

Tech stack
c
Domain
cliperformance
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
TCP basicsC programmingiperf usage
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
25
Research direction
Investigate the implementation of the n flag in iperf3's source code, particularly in files like src/iperf api.c or src/iperf tcp.c. Examine the logic for when a TCP RST is sent after receiving data. Look for any related discussions in the comments on this issue for potential clues about the expected behavior or known limitations.