Subject: [SIP] sip call Scheduling service

From: "Mauricio Bolaños Arturo" <[email-masked]>
Date: Fri, 21 Jul 2000 10:41:42 -0500

Hi everyone!

If I would like to make a sip call Scheduling service could I make it of the
following form?

The user sends an INVITE request to a proxy server with a SDP body  in which
there is a field "t=" or "r=" with information about the time (hour, minute)
that he wants to make the call. The server catches the request and look that
the message body has the time field ( "t=" or  "r=" or both) and sends this
information to the service logic. Time later when the call desired hour
arrives, the proxy server sends an INVITE request to the destination, and if
he accepts it then the proxy sends an INVITE request or a  message response
( 2xx) to the origin.
Is possible to make it using these SDP fields only??

thanks a lot

Mauricio Bolaños Arturo
ITEC -TELECOM
Bogotá Colombia

_______________________________________________
SIP mailing list
[email-masked]
http://lists.bell-labs.com/mailman/listinfo/sip

---

From: Jonathan Rosenberg <[email-masked]>
Date: Fri, 21 Jul 2000 12:11:35 -0400

This is overloading the meaning of these fields within SDP.

If you want to schedule a server to call you at some time, I suggest you
enter the data in a web page and have the application server use that
data to call you at the appropriate time. SIP is not meant to be an
event scheduling protocol.

-Jonathan R.

-- 
Jonathan D. Rosenberg                       72 Eagle Rock Ave.
Chief Scientist                             First Floor
dynamicsoft                                 East Hanover, NJ 07936
[email-masked]                     FAX:   (973) 952-5050
http://www.cs.columbia.edu/~jdrosen         PHONE: (732) 741-7244
http://www.dynamicsoft.com

---

From: Samir Chatterjee <[email-masked]>
Date: Fri, 21 Jul 2000 15:17:31 -0700

Doing it your way means that the proxy server will have to maintain unnecessary
state about this schedule event. While you can create a stateful server but
scalability will soon hit you. The necessary timing event can either be
preprogrammed in your end-point or by off-loading it to some app server which
can later initiate the call. Also, the "t=" and "r=" field have different
interpretations which become non-standard.

Dr. Samir Chatterjee
VoiceCore Technologies Inc &
Georgia State University

---

From: Henning Schulzrinne <[email-masked]>
Date: Fri, 21 Jul 2000 22:19:28 -0400

I suppose you could use "Retry-After" if somebody automatically calls
back, but that's really stretching it. Overloading the SDP media session
timing for session-level things is not a good idea.

Adding an automatic mechanism to follow a link at a particular time
would be a useful feature for calendar software, e.g., to automatically
announce a multicast meeting.