From: Hal Murray <hmurray@megapathdsl.net>
To: bloat@lists.bufferbloat.net
Cc: Hal Murray <hmurray@megapathdsl.net>
Subject: Re: [Bloat] How is bufferbloat prevented/fixed for UDP?
Date: Mon, 12 May 2014 21:33:28 -0700 [thread overview]
Message-ID: <20140513043328.63233406060@ip-64-139-1-69.sjc.megapath.net> (raw)
> 1)With UDP, you cannot uniquely identify a flow? This prevents an
> AQM-algorithm to drop packets for an (several) offending UDP flow(s).
UDP packets have port numbers, just like TCP.
> 2) Unlike TCP, UDP does not back down when encountering packet loss
Mumble. The OS doesn't do it. It has to be done in user code. But there is
no reason that it can't be done there even if it isn't done correctly as
often as we might like.
I think most DNS code is reasonably sane, mostly because the retransmit
timeout is several seconds and also because it only retransmits a few times.
The poster child for how to do it wrong is the NTP client that was shipped in
a zillion Netgear home routers with a hard wired NTP server. Dave Plonka did
a wonderful writeup.
http://pages.cs.wisc.edu/~plonka/netgear-sntp/
I call it required reading (and understanding) for anybody interested in
networks.
--
These are my opinions. I hate spam.
next reply other threads:[~2014-05-13 4:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-13 4:33 Hal Murray [this message]
[not found] <mailman.3.1399921203.1657.bloat@lists.bufferbloat.net>
2014-05-12 20:25 ` David Collier-Brown
-- strict thread matches above, loose matches on Subject: below --
2014-05-12 7:11 Forums1000
2014-05-12 20:21 ` Toke Høiland-Jørgensen
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