Re: [aqm] TCP ACK Suppression
David Lang <david@lang.hm> Wed, 07 October 2015 21:22 UTC
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Date: Wed, 07 Oct 2015 14:22:42 -0700
From: David Lang <david@lang.hm>
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To: Jonathan Morton <chromatix99@gmail.com>
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Cc: aqm@ietf.org, davecb@spamcop.net
Subject: Re: [aqm] TCP ACK Suppression
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On Wed, 7 Oct 2015, Jonathan Morton wrote: >> On 7 Oct, 2015, at 21:05, David Lang <david@lang.hm> wrote: >> >>>> It’s not “in the wild”, but this sort of thing is a headache for ELR. It >>>> essentially means that it won’t be able to use AccECN for its feedback >>>> (since AccECN doesn’t allow reconstructing a complex 32-packet history of >>>> ECN codepoints from a single ACK), but must introduce some other mechanism >>>> to feed back the required data to the sender. >>> >>> but if you are getting all 32 acks at the same time, with no other packets >>> flowing, are you going to be able to do anything sane? do you mark every one >>> of the acks with ECN (sending a super-strong backoff message), or only mark >>> one of the acks (sending a weak backoff message) >> >> Also, how can you tell how many acks you 'should' get? what happens if the >> 1500 byte packets get combined into 9000 byte jumbo packets for the final >> hop? how many acks 'should' you get? > > Let me turn that around: > > What should a node which aggregates 1500-byte packets into jumbo frames set > the ECN field to on the resulting jumbo packet, if the ECN fields of the > original packets had different values? I’m having some trouble imagining a > scenario where such destructive aggregation is permitted, except for TCP > proxies which should act as endpoints anyway. GSO, in particular, requires > the headers to be identical in that respect, ensuring that the original > packets can be reconstructed (assuming they are MSS sized). TCP data is supposed to be logically a continuous stream, it should not matter to the endpoints how it is packetized. So a conversion to/from jumbo frames should be acceptable. David Lang
- [aqm] TCP ACK Suppression Mikael Abrahamsson
- Re: [aqm] TCP ACK Suppression Greg White
- Re: [aqm] TCP ACK Suppression Mikael Abrahamsson
- Re: [aqm] TCP ACK Suppression LAUTENSCHLAEGER, Wolfram (Wolfram)
- Re: [aqm] TCP ACK Suppression Bless, Roland (TM)
- Re: [aqm] TCP ACK Suppression Mikael Abrahamsson
- Re: [aqm] TCP ACK Suppression Clark Gaylord
- Re: [aqm] TCP ACK Suppression Steve Bauer
- Re: [aqm] TCP ACK Suppression Francini, Andrea (Andrea)
- Re: [aqm] TCP ACK Suppression Richard Scheffenegger
- Re: [aqm] TCP ACK Suppression Greg White
- Re: [aqm] TCP ACK Suppression Bless, Roland (TM)
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression David Collier-Brown
- Re: [aqm] TCP ACK Suppression Jonathan Morton
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression Richard Scheffenegger
- Re: [aqm] TCP ACK Suppression Yuchung Cheng
- Re: [aqm] TCP ACK Suppression Jonathan Morton
- Re: [aqm] TCP ACK Suppression Jonathan Morton
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression Joe Touch
- Re: [aqm] TCP ACK Suppression Joe Touch
- Re: [aqm] TCP ACK Suppression Greg White
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression Joe Touch
- Re: [aqm] TCP ACK Suppression Yuchung Cheng
- Re: [aqm] TCP ACK Suppression Joe Touch
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression Joe Touch
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression Christian Huitema
- Re: [aqm] TCP ACK Suppression Rick Jones
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression Christian Huitema
- Re: [aqm] TCP ACK Suppression David Collier-Brown
- Re: [aqm] TCP ACK Suppression Simon Barber
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression Yuchung Cheng
- Re: [aqm] TCP ACK Suppression Joe Touch
- Re: [aqm] TCP ACK Suppression Joe Touch
- Re: [aqm] TCP ACK Suppression Joe Touch
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression Joe Touch
- Re: [aqm] TCP ACK Suppression Joe Touch
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] [tcpm] TCP ACK Suppression Greg White
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] TCP ACK Suppression Simon Barber
- Re: [aqm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Dave Taht
- Re: [aqm] [tcpm] TCP ACK Suppression Jonathan Morton
- Re: [aqm] [tcpm] TCP ACK Suppression Jonathan Morton
- Re: [aqm] [tcpm] TCP ACK Suppression Simon Barber
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Jonathan Morton
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Mikael Abrahamsson
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression Greg White
- Re: [aqm] [tcpm] TCP ACK Suppression Joe Touch
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang
- Re: [aqm] [tcpm] TCP ACK Suppression David Lang