sun
   microsystems              Systems Architecture Committee

_________________________________________________________________

Subject:       SIP Library Integration

Submitted by:  Venugopal Iyer

File:          PSARC/2006/402/opinion.ms

Date:          August 9th, 2006

Committee:     James D. Carlson, Kais  Belgaied,  Ed  Gould,
               Glenn   Skinner,   William  Sommerfeld,  Gary
               Winiger.

Product Approval Committee:

               Solaris PAC
               solaris-pac@sun.com

1.  Summary

This project delivers a library that implements the  Session
Initiation  Protocol,  which  is  used in telecommunications
applications.  It does not deliver the applications that use
it,  but  can be used to build applications that require a C
programming interface.

2.  Decision & Precedence Information

The project is approved as specified in reference  [1],  but
as  modified  by  the  technical  change  required listed in
Appendix A below.

The project the project may be delivered  in  a  patch/micro
release of Solaris via the ON consolidation.

3.  Interfaces

PSARC/2006/402         Copyright 2006 Sun Microsystems, Inc.

                           - 2 -

The project exports the following interfaces.

__________________________________________
|          Interfaces Exported           |
|_________|________________|_____________|
|Interface|  Classification|  Comments   |
|_________|________________|_____________|
|SIP API  |  Committed     |  See [1]    |
|<sip.h>  |  Committed     |  Header File|
|-lsip    |  Committed     |  Library    |
|_________|________________|_____________|

4.  Opinion

4.1.  State Management

The library has just one globally initialized  state,  which
means  that sip_stack_init() cannot be called more than once
in an application, and there should be no more than one user
of  the library in a given application.  Several ARC members
noted that this limitation means that it should not be  used
from within other libraries, and that the documentation must
be updated to make this limitation clear.

This discussion led to the first technical change  required,
listed in Appendix A below.

4.2.  Standards

Much of the review discussion for this case and  the  super-
seded   "Session   Initiation  Protocol  (SIP)  API"  (PSARC
2005/451) project dealt with the lack of  interoperable  API
standards  for  SIP,  and  the generally uneven state of the
open source  alternatives.   While  many  of  the  committee
members felt that this project would be more successful with
such a standard in place, there was no consensus to  require
this standardization.

4.3.  Documentation

An ARC member noted that the documentation for this  library
is very important if the library is to be usable by applica-
tion developers.  The project team is advised to  put  every
effort  into  making certain that the documentation is clear
and complete.

5.  Minority Opinion(s)

None

PSARC/2006/402         Copyright 2006 Sun Microsystems, Inc.

                           - 3 -

6.  Advisory Information

None

7.  Appendices

7.1.  Appendix A: Technical Changes Required

     1.   The sip_stack_init() function must fail if  called
          more than once within a single process.

7.2.  Appendix B: Technical Changes Advised

None

7.3.  Appendix C: Reference Material

Unless stated otherwise, path names are relative to the case
directory PSARC/2006/402.

1.   SIP API
     File:  commitment.materials/sipapi.pdf

PSARC/2006/402         Copyright 2006 Sun Microsystems, Inc.