So, the rate control does recognize that the first notify message can be empty
or might not contain all state:
$3.2: Thus, the first notification might be empty, or certain values might
The text that was originally quoted, that we're discussing is this:
A compliant notifier MUST generate notifications whenever the time
since the most recent notification exceeds the value in the "max-
interval" parameter. Depending on the event package and subscriber
preferences indicated in the SUBSCRIBE request, the NOTIFY request
MUST contain either the current full state or the partial state
showing the difference between the current state and the last
successfully communicated state.
The second sentence, taken out of context might be interpreted as Ben did - a
blanket prohibition on empty notify messages. Reading through again, with
complete context, I'm not sure that I agree with this assessment. If the
rate-control editors are amenable to a clarification in this section, it would
be nice, but I don't see it as necessary.
From: Ben Campbell [ben(_at_)estacado(_dot_)net]
Sent: Sunday, 21 March 2010 3:31 PM
To: Tschofenig, Hannes (NSN - FI/Espoo)
Cc: Thomson, Martin; aki(_dot_)niemi(_at_)nokia(_dot_)com;
salvatore(_dot_)loreto(_at_)ericsson(_dot_)com Loreto; Cullen Jennings; Rohan
Mahy; IETF-Discussion list; General Area Review Team; Hannes Tschofenig;
geopriv(_at_)ietf(_dot_)org; Adam Roach
Subject: Re: Gen-ART LC/Tekechat Review of draft-ietf-geopriv-loc-filters-10
On Mar 21, 2010, at 3:24 PM, Tschofenig, Hannes (NSN - FI/Espoo) wrote:
If rate-control gives the impression that it disallows empty NOTIFYs to
be sent then rate-control needs to change. If location is not available
at the time when the SUBSCRIBE hits the location server then the server
just cannot send something.
Do you agree with me?
We're not talking about NOTIFYs sent in response to a SUBSCRIBE. We're talking
about NOTIFY's sent as a result of a max-interval expiration, when using the
rate-control mechanism. The rate-control draft requires content in that
situation, and the geopriv-loc-filters draft recommends empty notifies in the
From: ext Ben Campbell [mailto:ben(_at_)estacado(_dot_)net]
Sent: 21 March, 2010 18:23
To: Thomson, Martin
Cc: Tschofenig, Hannes (NSN - FI/Espoo);
Cullen Jennings; Rohan Mahy; IETF-Discussion list; General
Area Review Team; Hannes Tschofenig
Subject: Re: Gen-ART LC/Tekechat Review of
On Mar 21, 2010, at 3:12 PM, Thomson, Martin wrote:
There's a few ways to handle that:
1) Treat rate-control as an informative reference, and say
you're doing something mostly like rate control, but not quite
identical. That would require quite a bit more normative
language to describe what you're actually doing.
2) Make this draft update rate-control to allow for empty
bodies when you don't have location info yet. Put some tightly
constrained language around it. so that this doesn't become a
3) Since rate-control has, to my knowledge, not been
pubreq'd yet, try to get the authors to modify the language to
allow for empty bodies for this use case.
I personally think 3 is the best path forward, as I think
the empty notify is generally useful for rate-control, and
implementor are likely to do it anyway.
I was not under the impression from reading rate-control
that that document was modifying 3265 to prevent notifiers
from sending an empty notify. But, your suggestion is a
reasonable one. Reading the rate-control text you quoted
earlier in the thread could lead to the impression that this
is the case. I've added the rate control authors to the thread.
I don't think it modifies 3265 in general, but it does seem to
normatively prevent empty NOTIFY requests as a result of a
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