Date: Fri, 11 Apr 2014 11:15:12 +0000 From: "Eggert, Lars" <lars@netapp.com> To: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org> Cc: Adrian Chadd <adrian@freebsd.org>, hiren panchasara <hiren.panchasara@gmail.com> Subject: Re: Patches for RFC6937 and draft-ietf-tcpm-newcwv-00 Message-ID: <C5823812-3972-410F-B50A-179898856F30@netapp.com> In-Reply-To: <259C9434-C6FE-42EA-823D-ECB024DBF3D7@netapp.com> References: <259C9434-C6FE-42EA-823D-ECB024DBF3D7@netapp.com>
next in thread | previous in thread | raw e-mail | index | archive | help
[-- Attachment #1 --]
Hi,
since folks are playing with Midori's DCTCP patch, I wanted to make sure that you were also aware of the patches that Aris did for PRR and NewCWV...
Lars
On 2014-2-4, at 10:38, Eggert, Lars <lars@netapp.com> wrote:
> Hi,
>
> below are two patches that implement RFC6937 ("Proportional Rate Reduction for TCP") and draft-ietf-tcpm-newcwv-00 ("Updating TCP to support Rate-Limited Traffic"). They were done by Aris Angelogiannopoulos for his MS thesis, which is at https://eggert.org/students/angelogiannopoulos-thesis.pdf.
>
> The patches should apply to -CURRENT as of Sep 17, 2013. (Sorry for the delay in sending them, we'd been trying to get some feedback from committers first, without luck.)
>
> Please note that newcwv is still a work in progress in the IETF, and the patch has some limitations with regards to the "pipeACK Sampling Period" mentioned in the Internet-Draft. Aris says this in his thesis about what exactly he implemented:
>
> "The second implementation choice, is in regards with the measurement of pipeACK. This variable is the most important introduced by the method and is used to compute the phase that the sender currently lies in. In order to compute pipeACK the approach suggested by the Internet Draft (ID) is followed [ncwv]. During initialization, pipeACK is set to the maximum possible value. A helper variable prevHighACK is introduced that is initialized to the initial sequence number (iss). prevHighACK holds the value of the highest acknowledged byte so far. pipeACK is measured once per RTT meaning that when an ACK covering prevHighACK is received, pipeACK becomes the difference between the current ACK and prevHighACK. This is called a pipeACK sample. A newer version of the draft suggests that multiple pipeACK samples can be used during the pipeACK sampling period."
>
> Lars
>
> <prr.patch><newcwv.patch>
[-- Attachment #2 --]
-----BEGIN PGP SIGNATURE-----
iQCVAwUBU0fOv9ZcnpRveo1xAQKPnAP+M4t/ovAfeWD9rBGqyB3pfUzGASg7B5OW
vAL3K6aaWc08OxduE5tw4KlsrdAAIa8p65fEBVWCBwxwthuzzQCVfIPf7948LLf5
2lWsVWSvuoAKmFS6+LS2iha+lDFbYgkV9GqrDsBahk53SLv2eCI3mx+048JAlw80
MOMAOtj2YNU=
=UgVh
-----END PGP SIGNATURE-----
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?C5823812-3972-410F-B50A-179898856F30>