I just saw this thread. Thanks Mikael for your response. Its the best
one available for this case, assuming (as the original poster has
confirmed) that this is all one dialog.
If there is early media flowing, you probably don't want to preempt it
with a generated ringback. But if there is no media flowing, then a
generated ringback would probably be a good idea.
But this rendering behavior is largely an implementation issue. If you
do it well then people will like your device. If you do it poorly, then
people won't. And there is plenty of room for innovation, especially
with devices having more capabilities. For instance, you might indicate
the alerting status visually if your device can do that. Or you could
mix a ringback with the incoming audio, though you might have difficulty
finding a way to do that which is acceptable to people.
Thanks,
Paul
Mikael Magnusson wrote:
> On Thu, Aug 06, 2009 at 05:27:10PM +0530, Abhishek Dhammawat wrote:
>> Hi
>>
>> In my opinion RBT(Ring Back Tone) should be played.
>>
>> regards
>> Abhishek Dhammawat
>>
>
> Since nobody has mentioned RFC 3960 I thought it would be appropriate to
> quote a portion of section 3.2[1].
>
> With this in mind, a UAC should develop its local policy regarding
> local ringing generation. For example, a POTS ("Plain Old Telephone
> Service")-like SIP User Agent (UA) could implement the following
> local policy:
>
> 1. Unless a 180 (Ringing) response is received, never generate
> local ringing.
>
> 2. If a 180 (Ringing) has been received but there are no incoming
> media packets, generate local ringing.
>
> 3. If a 180 (Ringing) has been received and there are incoming
> media packets, play them and do not generate local ringing.
>
> Note that a 180 (Ringing) response means that the callee is
> being alerted, and a UAS should send such a response if the
> callee is being alerted, regardless of the status of the early
> media session.
>
> I think 3 above answers the original question about local ringtone
> generation.
>
> /Mikael
>
> [1]http://tools.ietf.org/html/rfc3960#section-3.2
>
>> 2009/8/6 Abhishek Dhammawat
>> <abhishek.dhamma...@aricent.com<mailto:abhishek.dhamma...@aricent.com>>
>> Hi
>>
>> I would request you not to remove the original question from the mail chain
>> for better understanding of the issue I am putting the question by Miguel
>> orielly again
>>
>>
>> "I am wondering if the below scenario is valid or not.
>>
>> <-- 183 (with SDP) then,
>> <-- 180 (without SDP)
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