Re: [tsvwg] [Technical Errata Reported] RFC3168 (6494)

["Black, David" <[e-mail]>]

Bob,

> If it is decided that RFC3168 updates RFC791, then I think RFC3168 ought 
> not to also say that it updates RFC2474.

Hmm - if one applies the RFC 2474 and RFC 3168 updates to RFC 791 in ascending order of RFC number, the intended result is obtained.

I still think it's useful for RFC 3168 to continue to update RFC 2474 to say that the 2-bit CU (Currently Unused) field introduced in that RFC (and not present under that name in RFC 791) is now the ECN Field in addition to updating RFC 791 directly.  I'd be more inclined to agree that RFC 2474 doesn't need to be updated if that RFC hadn't introduced a new name for that field.

Thanks, --David
(author of both RFC 2474 and RFC 3168)

-----Original Message-----
From: Bob Briscoe <[e-mail]> 
Sent: Wednesday, March 24, 2021 5:58 PM
To: [e-mail]
Cc: [e-mail]; [e-mail]; [e-mail]; Black, David; [e-mail]; [e-mail]; [e-mail]; RFC Errata System
Subject: Re: [tsvwg] [Technical Errata Reported] RFC3168 (6494)


[EXTERNAL EMAIL] 

Joe,

I previously wondered myself whether RFC3168 updates RFC791 {Note 1}.
I came to the conclusion that the authors considered that RFC3168 
updated RFC2474 (which in turn updated RFC791). Otherwise, there would 
be no reason for RFC2474 to be in the updates header as well.

There is an appendix in RFC3168 on the history of the IPv4 ToS octet:
     https://tools.ietf.org/html/rfc3168#section-22
It shows (to me) that RFC3168 was considered to be the latest update in 
the long ancestral line of the ToS octet, rather than directly updating 
RFC791:

If it is decided that RFC3168 updates RFC791, then I think RFC3168 ought 
not to also say that it updates RFC2474.



Bob

{Note 1}: When I submitted the erratum to RFC3168 that added RFC2003 to 
the Updates header:
https://www.rfc-editor.org/errata/eid2660


On 24/03/2021 20:29, RFC Errata System wrote:
> The following errata report has been submitted for RFC3168,
> "The Addition of Explicit Congestion Notification (ECN) to IP".
>
> --------------------------------------
> You may review the report below and at:
> https://www.rfc-editor.org/errata/eid6494
>
> --------------------------------------
> Type: Technical
> Reported by: Joe Touch <[e-mail]>
>
> Section: Header
>
> Original Text
> -------------
> Updates: 2474, 2401, 793
>
> Corrected Text
> --------------
> Updates: 2474, 2401, 793, 791
>
> Notes
> -----
> This is the first standards-track RFC to assign the two unused bits of the IP TOS byte to ECN. Granted it was suggested in RFC2481, but that was experimental and unable to update RFC791 because it would create a downref.
>
> Instructions:
> -------------
> This erratum is currently posted as "Reported". If necessary, please
> use "Reply All" to discuss whether it should be verified or
> rejected. When a decision is reached, the verifying party
> can log in to change the status and edit the report, if necessary.
>
> --------------------------------------
> RFC3168 (draft-ietf-tsvwg-ecn-04)
> --------------------------------------
> Title               : The Addition of Explicit Congestion Notification (ECN) to IP
> Publication Date    : September 2001
> Author(s)           : K. Ramakrishnan, S. Floyd, D. Black
> Category            : PROPOSED STANDARD
> Source              : Transport Area Working Group
> Area                : Transport
> Stream              : IETF
> Verifying Party     : IESG
>

-- 
________________________________________________________________
Bob Briscoe                               http://bobbriscoe.net/