[SIPForum-discussion] Implementation of Session Inprogress

[Sriram Subramanian]

Hi,
     I will try to explain the basic behaviour i have seen

1)183 session progress is mainly used in case of EARLY MEDIA NEGITOTIATION
to provide the enduser an announcement .Generally it will be having a
require:100 Rel header which says that this provisional response needs to
transmitted reliably and needs an Provisional ACK ,So u might be seeing a
PRACK and 200 OK following an 183 Session Progress Response.
2)180 Ringing is a normal Ringing response which indicates an ALERTING state
,This comes as a part of BASIC call signalling and not in case of point
mentioned above. Point to be noted is even 180 Ringing can have a Require
:100 Rel but not mandatory.
You can also refer RFC 3261 Section 21.1.2 and 21.1.5 for a higher level
explanation.

Regards,
Sriram

On Mon, Nov 2, 2009 at 10:40 PM, kks balaji <balaji.sivam at gmail.com> wrote:

> Hi,
>
> Anyone can explain the session progress(183) and ringing response(180) in
> SIP.
>
> Thanks in advance,
> Balaji.
>
>
> _______________________________________________
> This is the SIP Forum discussion mailing list
> TO UNSUBSCRIBE, or edit your delivery options, please visit
> http://sipforum.org/mailman/listinfo/discussion
> Post to the list at discussion at sipforum.org
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sipforum.org/pipermail/discussion/attachments/20091103/b4db710f/attachment-0002.html>