Inline.

ext Adam Roach wrote:
> On 7/24/07 9:36 AM, Jonathan Rosenberg wrote:
>>
>>>  The conditional header field can also be wildcarded using the special
>>>    "*" entity-tag value.  Such a condition always evaluates to true
>>>    regardless of the value of the current entity-tag for the resource.
>>>
>>>    Example:
>>>
>>>       Suppress-Notify-If-Match: *
> 
> We discussed this briefly at the microphone -- the answer can be
> paraphrased as "about half the stuff in Mohammad's notify-pause draft
> that we'll be discussing in SIPPING on Thursday."

As I said in the session today, this is not to pause a subscription at
all; it only affects the very next NOTIFY that the SUBSCRIBE is about to
generate. So I don't see where the overlap here is. (However, there is
considerable overlap with the notify-pause and the throttle draft, which
I used to author long ago when my hair was a lot shorter...)

The use-cases for the wildcard are as follows (also mentioned at the end
of 4.3.):

- Heartbeat, or liveliness check. Using Suppress-Notify-If-Match: *, the
watcher can check whether a resource is alive: a 204 response says it
is, a 404 says it is not.

- Meta-data retrieval. Just like a HEAD in HTTP, a SUBSCRIBE with
Suppress-Body-If-Match: * will generate a NOTIFY without the body but
with the full header, including the current SIP-ETag.

I agree that these are not cornerstone use-cases for this draft, but
they represent some low-hanging fruit that would be difficult to add as
an extension.

I think it is beneficial to make notifiers understand wildcards from the
very beginning.

(I believe it is also a trivial implementation effort. I mean it's a
single additional string comparison in addition to matching the given
etag value with the current etag value of the resource, which the
notifier in any case needs to perform.)

Cheers,
Aki


_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [EMAIL PROTECTED] for questions on current sip
Use [EMAIL PROTECTED] for new developments on the application of sip

Reply via email to