nanog mailing list archives
RE: TCP congestion control and large router buffers
From: Mikael Abrahamsson <swmike () swm pp se>
Date: Tue, 14 Dec 2010 18:50:36 +0100 (CET)
On Tue, 14 Dec 2010, George Bonser wrote:
that sort of delay. Some form of AQM is probably a good thing as would be the wider use of ECN. Finding out that a buffer filled and a packet (or many packets) was dropped five seconds after the fact, isn't going
ECN pretty much needs WRED, and then people need to implement that first. The only routing platform I know to support it is 7200 and the other types of cpu routers from Cisco running fairly recent IOS (seems to have been introduced in 12.2T).
http://www.cisco.com/en/US/docs/ios/12_2t/12_2t8/feature/guide/ftwrdecn.html
You need enough buffering to satisfy packets "in flight" for a connection on the other side of the planet but man, what he has been reporting is just insane and it would be no wonder performance can be crap.
Yeah, 30-60ms of buffering is what I have favoured so far.With L2 switches you don't get anywhere near that, but on the other side a few ms of buffering+tail drop has much less impact on interactive applications compared to seconds of buffering.
-- Mikael Abrahamsson email: swmike () swm pp se
Current thread:
- TCP congestion control and large router buffers Vasil Kolev (Dec 09)
- Re: TCP congestion control and large router buffers Mikael Abrahamsson (Dec 09)
- Message not available
- Re: TCP congestion control and large router buffers Mikael Abrahamsson (Dec 13)
- Message not available
- Re: TCP congestion control and large router buffers Mikael Abrahamsson (Dec 14)
- RE: TCP congestion control and large router buffers George Bonser (Dec 14)
- RE: TCP congestion control and large router buffers Mikael Abrahamsson (Dec 14)
- Message not available
- Re: TCP congestion control and large router buffers Mikael Abrahamsson (Dec 09)
- Re: TCP congestion control and large router buffers Jim Gettys (Dec 20)
- Re: TCP congestion control and large router buffers Mikael Abrahamsson (Dec 20)
- Re: TCP congestion control and large router buffers Sam Stickland (Dec 21)
- Re: TCP congestion control and large router buffers Fred Baker (Dec 21)
- Re: TCP congestion control and large router buffers Jim Gettys (Dec 22)
- Re: TCP congestion control and large router buffers Fred Baker (Dec 22)
- RE: TCP congestion control and large router buffers George Bonser (Dec 22)
- Re: TCP congestion control and large router buffers Carsten Bormann (Dec 23)
- <Possible follow-ups>
- TCP congestion control and large router buffers Jim Gettys (Dec 14)