Re: [spfbis] Review of draft-ietf-spfbis-experiment-05

[Scott Kitterman <[e-mail]>]

On Monday, April 23, 2012 03:40:21 AM Murray S. Kucherawy wrote:
> Comments inline (alas):
> 
> From: [e-mail] [mailto:[e-mail]] On Behalf Of
> Barry Leiba Sent: Sunday, April 22, 2012 1:58 PM
> To: [e-mail]
> Subject: [spfbis] Review of draft-ietf-spfbis-experiment-05
> 
> OLD
>    3.  Although the two mechanisms often used different email addresses
>        as the subject being evaluated, no data collected showed any
>        substantial operational benefit (e.g., cheaper processing,
>        improved accuracy) to using Sender-ID over SPF.
> 
> I suggest "to using either mechanism over the other."
> 
> [MSK: I don't think that's correct.  Sender ID has a substantially higher
> processing cost given that it requires accepting the DATA part of the
> message and has an obviously higher cost to extract the various identifiers
> the PRA algorithm considers.  SPF, purely compute-wise, is cheaper. 
> However, their accuracy is comparable.  If we want to be clear, we can say
> their accuracies are about the same, but SPF is operationally cheaper.]

SPF is also not fundamentally incompatible with existing internet standards in 
a way that prevents it from being advanced, documented in a different appeal 
[1].  One very good answer to "Why advance SPF and not Sender ID?" is that 
there are standards issues with Sender ID that don't exist with SPF.  Even if 
they had equivalent operational complexity/cost, that would, IMO, be enough to 
be determinant.

Scott K

[1] http://www.ietf.org/iesg/appeal/leibzon-2005-08-29.txt