[e2e] Fwd: Camel's nose in the tent

[John Day]

At 10:53 PM -0400 8/10/01, David P. Reed wrote:
>At 07:29 PM 8/10/01 -0400, John Day wrote:
>>Actually, my understanding of SMTP is that it is intended to be as 
>>much an application relay as X.400?  No.  I would agree.  The ends 
>>were the ends of a transport layer connection, i.e. TCP.
>
>The end-to-end argument applies at each protocol layer, not just the 
>transport layer.  Both the rationale for it, and the explicit 
>description we wrote in our paper apply at application layers as 
>well.

I would agree with that. Although I have been told by experts that 
that isn't the case. But just for the record, does the application 
layer have the same scope as the layer below it?

>
>You could claim that an SMTP connection is only one hop.  But each 
>relay step is specified in the protocol, and the UA's at source and 
>destination are the ends.

Right, and to have reliable transfer you need an end-to-end protocol 
that you don't have.  So exactly how is the SMTP end-to-end?

>
>In regard to reflectors and listserv's, they are ends as far as SMTP 
>is concerned - because they are UA's as far as SMTP is concerned.

And also, how does end-to-end apply to the data link layer?

Take care,
John