Re: [apps-discuss] Adoption of draft-kucherawy-received-state?

Dave CROCKER <> Sun, 15 January 2012 00:48 UTC

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Date: Sat, 14 Jan 2012 16:48:23 -0800
From: Dave CROCKER <>
Organization: Brandenburg InternetWorking
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Subject: Re: [apps-discuss] Adoption of draft-kucherawy-received-state?
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On 1/13/2012 10:53 AM, John C Klensin wrote:
> SMTP rather carefully defines "trace information" or "trace
> headers" and then limits that category to two types of

What is the import of this observation, relative to the current proposal?

You appear to be intending it as a constraint, but I don't understand how, 

> In any event, we have discovered repeatedly (and sometimes
> painfully) that the the Received header field is not well
> designed for extensibility.

I don't recall seeing these claims before or documentation that they are valid. 
  Can you provide some citations?

Note that the definition of the Received: header field provides a registry for 
addition of new clauses, so you appear to be saying that extensibility is not 

>        It depends on an ordered,
> context-dependent, reserved keyword model (something I don't

If you are saying that the specific placement of the clause is essential, then 
please document this requirement -- beyond what is in the RFC5321 spec and the 
proposed clause spec -- both in terms of what you believe is acceptable and 
different from the current specification and also the basis for this.

>       we should have a serious discussion about how far
> we want to go in extending "Received:" and when it is time to
> add one or more additional Trace header fields, possibly with a
> typology of functions that each serves (beyond "inserted by a
> transit MTA or something else") and

Please review the latest version, specifically the 'Discussion' section, which 
provides exactly the consideration you are calling for.

 >      with a syntax that is
> clearly name-value based, rather than even partially dependent
> on parser recognition of specific keywords.

I don't understand the requirement you are proposing, since the "name" of a 
name/value pair is a specific keyword.  Hence, your saying "rather than" appears 
to be contradictory.

You seem to be meaning something else, but I can't guess what.

> Let's not turn "Received:" further into a kludge just because it
> is there.

How is it already a kludge?



   Dave Crocker
   Brandenburg InternetWorking