[142507] in North American Network Operators' Group
Re: [pfSense Support] Strange TCP connection behavior 2.0 RC2 (+3)
daemon@ATHENA.MIT.EDU (Tony Finch)
Wed Jun 29 07:19:20 2011
Date: Wed, 29 Jun 2011 12:18:08 +0100
From: Tony Finch <dot@dotat.at>
To: Mikael Abrahamsson <swmike@swm.pp.se>
In-Reply-To: <alpine.DEB.2.00.1106290719220.19581@uplift.swm.pp.se>
Cc: "williamejsalt@googlemail.com" <williamejsalt@googlemail.com>,
NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Mikael Abrahamsson <swmike@swm.pp.se> wrote:
>
> Well, then you run into the nice problem of the RNCs only having 400 kilobytes
> of buffers per session and will drop packets if they receive more packets than
> that, or sometimes even just because they receive a burst of a few tens of
> packets at GigE linerate (because the customer with large TCP window size is
> talking to a GigE connected server).
Excessively large buffers are a problem because they break TCP's RTT
measurement. Also TCP cannot measure the available bandwidth without
packet loss.
Tony.
--
f.anthony.n.finch <dot@dotat.at> http://dotat.at/
Biscay: Northerly or northwesterly, but northeasterly in far southwest 4 or 5,
occasionally 6 in east and far southwest. Slight or moderate. Mainly fair.
Good.
