i read that speex is a wideband codec with fec and bandwidth throttling. is it a good codec to use? im thinking about trying it out
also i was looking into g722 vs g711. if g722 has the same bandwidth requirements should it be used instead of g711 if the device supports it? the quality is supposed to be better.
Since the phone network is still limited to a an 8Khz PCM signal, anything other that uLaw (g.711) is limited to traffic between endpoints on your network.
If you use a CODEC other than native you will be adding transcoding duties to Asterisk, this consumes CPU resources and needs to be accounted for.
The only time I used g.722 was an environment with heavy internal conferencing.
Speex is definitely something you want to consider for WAN and unreliable networks. IT has FEC (forward error correction) which kinda guarantees packet transmission and correction if something does go wrong.
Also, one thing i love about speex is that it is on EVERY SINGLE PHONE I’VE USED SO FAR …so compatibility is important too.
But, i am very very much excited and interested in the development of OPUS (predecessor to Speex and sort of a fork of speex, the SILK codec). As they say, one codec to rule em all, that would possibly be OPUS…
Not predecessor, but the successor to…hehe 
obviously
yea i have noticed that all the softphones have speex enabled but i dont see it as a option on my polycom. i wish they had it.