Iñaki Baz Castillo wrote:
> El Thursday 08 May 2008 16:20:29 Paul Kyzivat escribió:
>> Iñaki Baz Castillo wrote:
>>> El Thursday 08 May 2008 15:45:53 NC Reddy escribió:
>>>> Hi,
>>>> I have the following question:
>>>>
>>>>
>>>> - Can UAS sends multiple answers for same offer:
>>>> - i.e 183 (Answer-1)
>>>> - 180(Answer-2)
>>>> - 200 Ok(Answer-2)
>>>>
>>>> Does the above UAS behavior is valid?.
>>> Sure, even if 183 and 180 have different "To" tag they are completely
>>> valid since it's the same as when parallel forking.
>> That would be "*only* if they have different To-tags", and in that case
>> it won't be the same UAS sending them.
>
> Yeah :)
>
>
>> So the answer is NO.
>
> "NO" to all? and what about if AS does as a B2BUA and uses a single "To" tag
> for all replies?
The offeranswer draft explains. THere can be only one answer per offer
per dialog. Sometimes the same answer is send in multiple messages, but
technically only one of them is the actual answer.
In the B2BUA case above, because it is a UA it is bound by the same
rules. If it is forking on the other side, then it has two choices:
- sort things out and pick the answer it wants to send to the UAC,
while handling the others itself.
- It can send the multiple answers to the UAC using different to-tags,
the same way a proxy would. In that case I would argue that it is
two UAs rather than one. (Well, it was already at least two UAs,
or three, so I guess this would make it four UAs.)
But that is more a philosophical question.
Paul
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