Subject: Re: CAP TODO: single threaded

From: "John Stracke" <[email-masked]>
Date: Thu, 15 Nov 2001 10:33:13 -0500

>However, the WG decided for bounded latency a long time ago.

I actually can't find such a decision in the archives.  Key points:

* The first mention of bounded latency is in ietf-calsch-rtreq-00.txt, 
posted in March 1997 (http://www.imc.org/ietf-calendar/archive1/msg00906.html); it includes a requirement for bounded latency.  However, there is no 
explanation for this requirement, nor, as near as I can tell, was there 
consensus on it on the list; see, for example, 
<http://www.imc.org/ietf-calendar/archive1/msg00834.html>, where Einar 
Stefferud takes the position that a realtime requirement is not achievable 
in general.  The ensuing thread includes support from various people 
(e.g., John Klensin, 
<http://www.imc.org/ietf-calendar/archive1/msg00841.html>, and Bob 
Mahoney, <http://www.imc.org/ietf-calendar/archive1/msg00845.html>).

* In April 1997, the notes from the Memphis meeting (http://www.imc.org/ietf-calendar/archive1/msg00970.html) indicate that the sense of the meeting had been that bounded latency was 
not needed, and asks for consensus from the list.

* Bounded latency is not mentioned again on the list until May 1998 
(http://www.imc.org/ietf-calendar/archive1/msg02569.html), when Steve 
mentions that, as of the LA meeting, he got the sense from people that 
bounded latency "was not really an issue".

* The next time bounded latency is mentioned is in 
ietf-draft-calsch-irip-04.txt, posted in March 1999 (http://www.imc.org/ietf-calendar/archive1/msg02940.html), which contains the feature.  As near as I can tell, it was added with no discussion on the list.

* The first version of CAP (http://www.egenconsulting.com/cap.txt) was 
posted in June 1999; it seems to have inherited bounded latency from iRIP. 
 Again, I cannot find discussion on the list supporting it.

* I haven't dug through the archives past this point; but I have been in 
the group since January 1999, and I do not remember any active decision in 
favor of bounded latency.

So.  It may be true that the people writing the iRIP and CAP documents 
decided on bounded latency a long time ago; but, if it was not discussed 
on the list, the WG has not decided.

Can anybody explain to me whom bounded latency is supposed to benefit? It 
wastes CS resources to cancel a request that's taken too long; it 
complicates the protocol for implementors; and it impairs usability by 
complicating the user's view of the system.

/=======================================================\
|John Stracke                   |Principal Engineer     |
[email-masked]  |Incentive Systems, Inc.|
|http://www.incentivesystems.com|My opinions are my own.|
|=======================================================|
|Belief is not relevant to truth.                       |
\=======================================================/

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From: Doug Royer <[email-masked]>
Date: Thu, 15 Nov 2001 14:05:57 -0700

> I actually can't find such a decision in the archives.  Key points:

It pre-dates CAP when there was iRIP and the proposal
for an HTTP based CAP.

When iRIP went away, the agreement with the iRIP proponents
was the it remain in CAP. I know it was a discussion, but it
was a long time ago.

The real issue here is that we can't keep re-opening old
issues if we want CAP out the door. We are removing the CAP
transport in favor of BXXP, and that is a good thing. I understand
that BXXP might have issues with bound latency, we could do
in the in data (vs transport). Or we could drop it. But
we really need to be careful not to just keep reopening old
issues just because we don't like them.

-Doug