Re: T2 - Assertions and Questions

[Colleen Evans <cevans@sonicsoftware.com>]

It all comes down to how you look at intermediaries, doesn't it?  In the case where
each 'chasm' is considered a hop, then your argument holds.  There's a reliable
hand-off to the next hop and the reliability responsibilities cascade.   However, if
the 'chasm' is considered the end to end delivery, then a weak link is a problem.

I think your point that we need to clearly define the possible, meaningful and
realistic use cases and see how the spec matches up is very valid.  In my mind,
there are two categories of scenarios involving intermediaries:  (1) the
intermediary provides some value-add such as BP, translation, etc. or (2) the
intermediary is purely a switching mechanism.  These categories also impact the CPA
discussion in terms of where the business agreements exist (between the end points,
the end point and intermediary hop(s), etc.)

Colleen

Dan Weinreb wrote:

>    Date: Mon, 13 Aug 2001 14:40:53 -0600
>    From: Colleen Evans <cevans@sonicsoftware.com>
>
>                                                                    If the
>    intermediary hops aren't reliable, the bridge doesn't connect the end points.
>    You're only as strong as your weakest link.
>
> I don't think that the principal of "You're only as strong as your
> weakest link" applies here.
>
> Consider the analogy with TCP/IP.  The IP itself is not reliable.  It
> is purely "best-effort".  Any router is free to drop an IP packet if
> it wants to.  And yet, TCP, built upon IP, is reliable.  The
> technology of using retranmissions, acknowledgements, and duplicate
> elimination allows reliable once-and-only-once semantics over an
> unreliable substrate.
>
> -- Dan

--
Colleen Evans
Principal Product Manager
Sonic Software Corporation
phone:  720 480-3919 or 303 791-3090
email:  cevans@sonicsoftware.com
website:  http://www.sonicsoftware.com