资源

OpenH323 项目:

http://www.openh323.org/

http://www.openswitch.org/

http://www.linuxjack.com/

http://www.linuxtelephony.org/

http://www.asteriskpbx.org/

http://www.voxilla.org/

http://www.opengatekeeper.org/

http://www.packetizer.com/

Vovida Networks, Inc. — 开源协议栈（最近被思科收购）

http://www.vovida.com/opensource.html

http://www.cs.columbia.edu/~hgs/rtp/

http://www.cs.columbia.edu/~hgs/sip/

http://www.pulver.com/

http://www.ietf.org/html.charters/iptel-charter.html