Subject: RE: [SIP] Announcements in SIP

From: Jaime Jimenez <[email-masked]>
Date: Thu, 25 Jan 2001 09:55:20 -0500

I am new to this list and I have a quick question on this item.

Are we looking to provide "in-band" Announcements for what traditionally
been call "network announcements?"  In the US PSTN we are required to
provide "answer supervision" (meaning to answer the call) before a
"customer" announcement can be played to the calling party. So if the call
is queued, then the call needs to be answered before a message can be
provided.

Having said that, there are other scenarios where the "network" can provide
recorded announcements (congestion, etc.) that are provided, but letting the
end system map that locally maybe the best approach.

Jaime

If it can be done (getting around the 4xx response issue), it look great.
Rather than recreating the bugs (I mean features :-) of the PSTN [sending
aural signaling in-band as "early media"], we provide useful solutions to
end users [providing informative responses, using local resources when
possible or network resources if necessary].

> On seeing a 404 response, an end UA *may* choose to use the information in
> the CallProgress-Info header if it is not capable of providing local
> annoucements, otherwise, it could render to the user the information
> provided in the CallProgress-Info header. How does this look?
>
[snip]

---

From: hammer michael <[email-masked]>
Date: Wed, 31 Jan 2001 17:36:49 -0800

I second the idea to try to filter out PSTN inefficiencies if 
possible.  That said, would packetized one-shot (voice-mail or data) 
responses be preferred over streamed connections?

Another thought to keep in the back of the mind, you might also want to 
consider the possibility that the user or the terminal is not native to the 
location of the proxy.  Put another way, if the announcement played to me 
is in Chinese, it would do me no good.  A data message might be easier to 
translate, but would present the same problems.  Any 3G mobile-related 
solutions?

Mike Hammer

At 09:55 AM 01/25/2001 -0500, Jaime Jimenez wrote:

>is queued, then the call needs to be answered before a message can be provided.
>
>Having said that, there are other scenarios where the "network" can 
>provide recorded announcements (congestion, etc.) that are provided, but 
>letting the end system map that locally maybe the best approach.
>
>Jaime
>

_______________________________________________
This list is for continuing development of the SIP protocol.
The sip-implementer's list is the place to discuss implementation,
and to receive advice on understanding existing sip.
To subscribe to it, send mail to [email-masked] with
"subscribe sip-implementors" in the body.