RE: [Serusers] Summary of using SER as an app server - sr-users

6 Oct 2004

I am curious to see how (even if) the SDP is handled by an app using ser's app server
fifo.
Does ser give an app access to SDP payloads? 
Can the app specify the SDP payload on an outbound call (outbound w/respect to ser)?
Can the app see the SDP payload on an inbound call (inbound w/respect to ser)?
Can the app specify which codec to use on a reply to an INVITE?
All of these features are required in order for the app to initiate a (meaningful) call
via ser.

Mr Kuthan and Mr Darilion mentioned the click-to-dial feature of serweb as an example of
initiating a call from ser.
Does ser participate in the SDP in click-to-dial, or does it just let the endpoints
negotiate SDP?
Where is the click-to-dial source code?
I browsed serweb's cvs but I can't find it.

sorry for so many questions in a single email...

-----Original Message-----
From: Franklin, Allen 
Sent: Tuesday, October 05, 2004 7:35 AM
To: 'Jiri Kuthan'; serusers(a)lists.iptel.org
Subject: RE: [Serusers] Summary of using SER as an app server

Can I use the app server functionality of SER to initiate a SIP call?

In order to initiate a SIP call, the app needs to be able to specify RTP
parameters to go into SDP bodies of SIP messages, and to have access to
the SDP info returned by the callee.

Some entity (SER or the app?) needs to do SDP negotiation.

I don't see mention of this in the SER docs.

Am I asking for something that SER does not support?

-----Original Message-----
From: Jiri Kuthan [mailto:jiri@iptel.org]
Sent: Monday, October 04, 2004 7:11 PM
To: Franklin, Allen; serusers(a)lists.iptel.org
Subject: Re: [Serusers] Summary of using SER as an app server

At 12:51 AM 10/5/2004, Franklin, Allen wrote:
...
 A very basic hook is provided that allows a script to
call functions in a user-provided shared library,
but this hook is only useful for rewriting the URI of the "current" message.

Thats incorrect. The shlibs can do and do much more than URI rewriting. See module list
and what they do.

...
 SER does not allow scripts or app server processes to
see or modify the SDP, so an app
server process could not be used to initiate a voice call. 
There are modules that do SDP mangling. nathelper for example.

...
 SER does not have a SIP parser as would be found in a
traditional SIP stack. 
I don't know what a traditional SIP stack is but if you mean something slow
that SER doesn't have it ;) It is not available as a separate library if you
mean that.

Otherwise your assessment has been correct. If you are looking for a real
application server (meaning a stateful call control element) than it is
not SER. We have AA (www.iptel.org/aa).

-jiri 