Het bronpakket opal downloaden:
This package contains the documentation and samples to program with the OPAL library.
The OPAL project aims to create a full featured, interoperable, Open Source implementation of the H.323 and SIP protocols that can be used freely by everybody. These protocols are most used for Voice over IP (VoIP) conferencing.
For more information on the OPAL project visit them at http://www.voxgratia.org/