ccaudio2 : GNU ccAudio ( http://www.gnu.org/software/ccaudio/ )
mediastreamer : Mediastreaming library for telephony application ( http://www.linphone.org/ )
silk : SILK (skype codec) library ( http://www.linphone.org )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a voip
For Paludis use this rsync : rsync://gentoo.zugaina.org/voip-portage
If you have a problem : ycarus(-at-)zugaina.org