From: Neal Cardwell <ncardwell@google.com>
To: sdrb@onet.eu
Cc: Netdev <netdev@vger.kernel.org>
Subject: Re: Variable download speed
Date: Tue, 23 Feb 2016 09:26:46 -0500 [thread overview]
Message-ID: <CADVnQy=-oh7Ue=Y0vP4ioGrRs7SeJBNq5bkkDVkpogyLpr+9zA@mail.gmail.com> (raw)
In-Reply-To: <alpine.LNX.2.20.1602231455260.29937@localhost.localdomain>
On Tue, Feb 23, 2016 at 8:57 AM, <sdrb@onet.eu> wrote:
> I published example pcap file under following link:
>
> https://www.dropbox.com/s/v8375ub16seyt1a/test7.pcap?dl=0
>
> I hope it is possible to download it without creating dropbox account.
Thanks for the trace. It looks like for the first 0.8 seconds of the
trace some non-TCP component on the receiving machine (app, CPU, CPU
power-saving mechanisms, NIC, or NIC driver) is limiting throughput to
78Mbit/sec (e.g. the very first window of 10 packets is ACKed at that
rate). Then the throughput increases to over 200 Mbit/sec. AFAICT it
doesn't look like the TCP layer is doing anything wrong. I'd look for
issues with those other components. It might help to report the
receiver application, receiver CPU type, kernel version, NIC, and NIC
driver.
neal
next prev parent reply other threads:[~2016-02-23 14:26 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-23 11:19 Variable download speed sdrb
2016-02-23 13:28 ` Neal Cardwell
2016-02-23 13:57 ` sdrb
2016-02-23 14:26 ` Neal Cardwell [this message]
2016-02-24 7:48 ` sdrb
2016-02-23 11:24 sdrb
2016-02-23 16:53 ` Rick Jones
2016-02-24 9:59 ` sdrb
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