Re: [tcpm] Detailed review of AccECN rev -04

Bob Briscoe <> Sat, 14 July 2018 16:00 UTC

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From: Bob Briscoe <>
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Date: Sat, 14 Jul 2018 17:00:13 +0100
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Subject: Re: [tcpm] Detailed review of AccECN rev -04
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Gorry, Mirja,

While reviewing conversations on the list for including in our slides in 
Montreal, I thought again about the conversation below from March...

On 13/03/18 16:49, Gorry Fairhurst wrote:
>>> A future standards-track document based on the AccECN experimental 
>>> RFC could update RFC3168.
>> No, I don’t it would update RFC3168. It does not change anything in 
>> that RFC. It also specified an additional meachismen (which we hope 
>> will deploy as the default). The only thing we change is the use of 
>> the NS bit in the SYN but that was previously unused; with or without 
>> ECN Nonce.
> OK that makes sense. 

Although nothing in AccECN updates RFC3168, the goal was not to fork the 
wire protocol, but instead to eventually provide a generic wire protocol 
that could either feed back to a host behaving like RFC3168 (one 
response per RTT) or behaving with an updated behaviour (e.g. L4S).

So, some time in the future we might want to work out whether / how to 
update RFC3168 with a new standards track feedback protocol.


Bob Briscoe