From: Michael Tuexen <firstname.lastname@example.org>
To: Xin Long <email@example.com>
Cc: "linux-sctp @ vger . kernel . org" <firstname.lastname@example.org>,
Marcelo Ricardo Leitner <email@example.com>
Subject: Re: add SPP_PLPMTUD_ENABLE/DISABLE flag for spp_flags
Date: Tue, 18 May 2021 21:19:21 +0200 [thread overview]
Message-ID: <DE8A113C-DF80-412E-A5C1-C0731E1757E2@freebsd.org> (raw)
> On 18. May 2021, at 20:33, Xin Long <firstname.lastname@example.org> wrote:
> On Tue, May 18, 2021 at 1:38 PM Michael Tuexen <email@example.com> wrote:
>>> On 18. May 2021, at 18:43, Xin Long <firstname.lastname@example.org> wrote:
>>> Hi, Michael,
>>> We're implementing RFC8899 (PLPMTUD) on Linux SCTP recently,
>>> and to make this be controlled by setsockopt with
>>> SCTP_PEER_ADDR_PARAMS, as in
>>> we need another two flags to add for spp_flags:
>>> Do you think it makes sense? if yes, does the RFC6458 need to update?
>>> if not, do you have a better suggestion for it?
>> It is great new that you want to implement RFC 8899. I plan to do the
>> same for the FreeBSD stack.
>> In my view, RFC 8899 is the right way to implement PMTU discovery.
>> So I will just use the SPP_PMTUD_ENABLE and SPP_PMTUD_DISABLE. I don't
>> think that the user needs to control which method is used.
>> I you want to support multiple versions, I would make that
>> controllable via a sysctl variable. But I think for FreeBSD, support
>> for RFC 8899 will be the only way of doing PMTU discovery. There
>> might be multiple choices for details like how to do the searching,
>> how long to wait for some events. These will be controllable via
>> So in my view, there is no need to extend the socket API. What do you think?
> OK, that makes sense to me.
> Another thing I want to know your opinion on is: do you think the HB
> should be created
> separately for PLPMTUD probe, instead of reusing the old HB that
> checks the link connectivity?
Yes. I think testing for connectivity is conceptually different
from testing a particular PMTU. When testing for PMTU, I think
about sending probe packets. Not that they consist of a HB chunk
bundled with a PAD chunk.
> As the HB for PLPMTUD probe might get lost, which we don't want to
> affect the link's
Yes, I agree completely.
>> Best regards
next prev parent reply other threads:[~2021-05-18 19:19 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-18 16:43 add SPP_PLPMTUD_ENABLE/DISABLE flag for spp_flags Xin Long
2021-05-18 17:38 ` Michael Tuexen
2021-05-18 18:33 ` Xin Long
2021-05-18 19:19 ` Michael Tuexen [this message]
2021-05-19 22:24 ` mleitner
2021-05-20 2:05 ` Xin Long
2021-05-20 7:06 ` tuexen
2021-05-20 15:13 ` Xin Long
2021-05-19 16:18 ` Xin Long
2021-05-19 18:15 ` Michael Tuexen
2021-05-19 18:44 ` Xin Long
2021-05-19 22:44 ` mleitner
2021-05-19 23:16 ` Michael Tuexen
2021-05-20 0:45 ` Marcelo Ricardo Leitner
2021-05-20 6:59 ` tuexen
2021-05-20 19:27 ` Marcelo Ricardo Leitner
2021-05-19 23:10 ` Michael Tuexen
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).