Subject: [salud] Expanding where Alert-Info can appear

From: [email-masked] (Dale R. Worley)
Date: Mon, 25 Mar 2013 17:38:57 -0400 (EDT)

Currently, we have this text at the start of section 1.2:

   1.2.  Alert-Info Header Field Usage Change

   This specification changes the usage of the SIP Alert-Info header
   field defined in the [RFC3261] by additionally allowing its use in
   all provisional responses to INVITE (except the 100 response).

This is correct, but it suggests that Alert-Info may not now be used
in provisional responses.  Looking at RFC 3261, Alert-Info may be used
in 180 responses, but not other responses.  I believe that we intend
to allow Alert-Info in all responses, so that it can be used in, for
example, 181 Call Is Being Forwarded and 182 Call Is Being Queued 
responses, for which ringback tones are often provided.

I think we should explain the situation more fully, perhaps by adding

   Previously, the Alert-Info header field was only permitted in 180
   (Ringing) responses.  But in telephony, other situations indicated
   by SIP provisional responses, such as 181 (Call Is Being Forwarded)
   and 182 (Call Is Being Queued), are often indicated by tones.
   Extending the applicability of Alert-Info allows the telephony
   practice to be implemented in SIP.

Comments?

Dale

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From: Paul Kyzivat <[email-masked]>
Date: Tue, 26 Mar 2013 07:08:50 +0800

WFM

On 3/26/13 5:38 AM, Dale R. Worley wrote:
> _______________________________________________
> salud mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/salud
>

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From: Laura Liess <[email-masked]>
Date: Tue, 26 Mar 2013 13:34:06 +0100

I am fine with the added text.

Thank you,
Laura

2013/3/25 Dale R. Worley <[email-masked]>