On Mon, 2010-04-05 at 15:09 -0400, Hadriel Kaplan wrote: > > > -----Original Message----- > > From: Scott Lawrence [mailto:xmlscott@xxxxxxxxx] > > Sent: Monday, April 05, 2010 2:30 PM > > To: Hadriel Kaplan > > > > The spec says in section 2.6 > > (Validity of Stored Configuration Data): > > > > The UA MAY use configuration data that is of unknown validity, > > or configuration data that is known to be no longer valid, while > > attempting to revalidate that data or obtain new data. > > > > So the UA may use the configuration data before any subscription is > > established - the subscription does not block anything (except getting > > change notices). > > Heh... weren't you just arguing about how optional requirements in > IETF docs are bad? ;) > > This form of optional is right up that alley. For example, if I am a > service provider who wants to not have Subscription mode, and the only > way to do it is through UA config framework itself by setting a config > field for "Subscribe-UA-Config="false" or whatever, then clearly the > UA's MUST use the config. A MAY statement does nothing. The draft is clear that the configuration data can modify any part of the procedures in the draft. Section 2: The User Agent MAY obtain configuration information by any means in addition to those specified here, and MAY use such information in preference to any of the steps specified below, ... So if you're looking for an escape clause, you've found it, but the rest of the sentence is important ...but MUST be capable of using these procedures alone in order to be compliant with this specification. > If it's not clear and exact as to what config data a UA is supposed to > use, and when, then you really do get "flaky service behavior" as you > were worried about in a previous email. I think that the wording of that particular statement is perhaps unfortunate, but have not found a better one. In effect, what we were trying to do is express that the UA is not required to wait until the subscription exists to use the data, and can continue to use the data should the subscription fail for any reason. This prevents various failure modes and/or delays in the UA when the Configuration Service is overloaded or otherwise unavailable. It's not an 'optional requirement' it's a non-requirement. _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf