Re: Chat: questions on 'accept-wrapped-types'

On 9/12/12 9:50 AM, Miguel A. Garcia wrote:
> On 11/09/2012 21:24, Paul Kyzivat wrote:
>> On 9/11/12 2:51 PM, Ben Campbell wrote:
>>>
>>> On Sep 11, 2012, at 1:46 PM, Ben Campbell <[email protected]> wrote:
>>>
>>>>
>>>> On Sep 11, 2012, at 1:17 PM, "Eric
>>>> Burger"<[email protected]> wrote:
>>>>
>>>>> We solved the three-out-of-four endpoints understand D problem
>>>>> years ago. See RFC 3459. UAC's mark the message as critical (gets
>>>>> rejected if unable to send to all recipients) or not critical (gets
>>>>> silently dropped or destination gets a notice).
>>>>
>>>> That's an interesting and likely useful approach. I'm concerned that
>>>> it's a bit of feature creep for this draft, though. At least, it's a
>>>> non-trivial feature that the working group had not contemplated so
>>>> far. Mapping rfc3459 to MSRP seems like an effort roughly equivalent
>>>> effort to when we did the delivery status notification work for
>>>> MESSAGE.
>>>
>>> Okay, before anyone jumps on that, on a more careful read of 3459, I
>>> realize it would be less work than DSN. But it's still a substantial
>>> new feature for this late in the draft's life cycle. That doesn't
>>> mean we can't add it if we Really Need It (TM) for the rest of the
>>> draft to be useful. Do we?
>>
>> ISTM that now we are realizing we have had the feature all along and
>> just never realized it. So there is nothing to do other than maybe point
>> out to people that they should do it.
>>
>>     Thanks,
>>     Paul
>>
>>>>
>>>> Can we live with some implementor guidance that they need to think
>>>> about this, and leave a formal solution as future work if anyone
>>>> wants to do it?
>>>>
>>>> Thanks!
>>>>
>>>> Ben.
>>>>
>
> At this point in time, I believe we don't really understand all the use
> cases and problems that we will get when we introduce the
> Content-Disposition handling parameter. Let me give you one example of
> added complexity:
>
> Alice sends a message to the chat room. The MSRP switch distribute to
> Bob and Charlie, because both indicated an accept-wrapped-types of "*".
> Bob accepts the content, but not Charlie. Charlie "MUST take the
> appropriate failure action " [RFC3459], but which one is it? And then,
> when the MSRP switch receives such 'failure action', what should it do
> towards the sender? And should it wait to aggregate 'failure actions'
> from several potential receivers?
>
> So, let's be pragmatical. We don't have time nor requirements to have
> this sophisticated feature at this late point in time. I will try to
> think of something simple (e.g., discard on error). If someone is
> interested, he or she should collect requirements and write an extension.
>
> Is this reasonable? If so, I will come up with text for review?

Yes, I am sympathetic that this is a rat hole that would be good to 
avoid for now.

I just don't want to see something done that *requires* action in 
conflict with what the Content-Disposition would call for. (IOW it 
should be ok for an implementation to be guided by the C-D handling 
parameter if it wishes.)

	Thanks,
	Paul