Question : Asterisk (Trixbox) 1.4.2.4 n-way calling / 3-way calling / conferencing

Hi Gurus,

I need help configuring n-way calling or 3-way calling.

I'm using Linksys SPA941 phones...When I'm talking to a user and try to conference in another caller, I press "conference" on the phone, dial the number and when the caller picks up and i press "join," instead of conferencing, it's transfering the call.

What do I need to do to get this working?

Answer : Asterisk (Trixbox) 1.4.2.4 n-way calling / 3-way calling / conferencing

Here your answer from the link above about G729.

It offers toll quality speech at a reasonably low bit rate of 8Kbps. However, it is a rather "costly" codec in terms of CPU processing time, therefore some VoIP phones and adapters (notably the Linksys/Sipura/Cisco brands) can only handle one G.729 call (channel) at a time. This can cause calls to fail if the user attempts to use three-way calling, or place simultaneous calls on both lines of a two-line device, and G.729 is the only allowed codec.