Subject: RE: [rddp] Some Marker Comments

From: "Williams, Jim" <[email-masked]>
Date: Fri, 24 Jan 2003 12:26:24 -0500

David Black wrote:
> Also, a while back, Jim commented:
> 
> > 5.  Some method needs to be created for a sender
> >     to notify the receiver of ability to align.
> >     There are strong arguments that this should
> >     be done at the transport, not the RDDP layer.
> >     (i.e. a new TCP option on the SYN segment).
> 
> IMHO (WG chair hat still off), the odds of a new TCP
> option for this purpose getting through tsvwg are close
> to zero (I've been involved in somewhat analogous attempts,
> and my ears are still ringing ...).

I hate to see important technical issues decided by
fear of being yelled at by people with gray beards. :)
On the other hand some valuable experience
comes along with the gray beards, and that should be factored
into the discussion.  If the fundamental objection is to
aligning TCP (as opposed to using a TCP option to do it)
then trying to sneak it by tsvwg by negotiating in-band
and pretending not to modify TCP seems like bad protocol
design as well as questionable politics.

> It would be better
> to pursue an inband notification mechanism that could also
> satisfy the "ensure no confusion about bytestream contents"
> requirement.  Getting that design and the underlying rationale,
> weaknesses, tradeoffs, etc. are worked out and well-described
> in an Internet-Draft ought to be done before considering
> whether the result makes a sufficient case for a new TCP
> option.

The fundamental choice is between:

 A.  "TCP is a byte stream protocol and thou shalt not attempt
      to use it otherwise."
and

 B.  "Let's treat TCP as a sequence of segments which the sender
      can construct, the network will preserve, and the receiver
      can exploit."

If the answer is A, then it's a waste of time to talk about either
TCP options or in-band notification of alignment.

If the answer is B, then in-band notification versus TCP option
is a legitimate debate.

I do object to the notion of, "Let's do B, but be sneaky enough
about it so that nobody looking at the wire can determine that
we aren't doing A, therefore tsvwg has no right to object."
It results in a bad and overly complex protocol motivated
by political rather than technical considerations.
> Thanks,
> --David
_______________________________________________
rddp mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/rddp

---

From: Caitlin Bestler <[email-masked]>
Date: Fri, 24 Jan 2003 11:51:56 -0600

On 1/24/03, Williams, Jim wrote:

>I do object to the notion of, "Let's do B, but be sneaky
>enough about it so that nobody looking at the wire can
>determine that we aren't doing A, therefore tsvwg has no
>right to object." It results in a bad and overly complex
>protocol motivated by political rather than technical
>considerations.

On the other hand I think it is legitimate to set an
objective of "Let's do B, but in such a way that no
intermediate network equipment is required to anything that
it would not have done for A."

I can even live with taking excruciating pain in drafting
standards so that they fully comply with A. But I do
strongly agree that it is going overboard if we add actual
complexity or overhead on the wire to meet a "cannot be
detected" goal, rather than a "fully interoperable with"
objective.

Caitlin Bestler
http://asomi.com/CaitlinBestler/
_______________________________________________
rddp mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/rddp