Hi
Asterisk 1.4 has native support for G722 pass-through, which means that two G722 capable phones can call one another using G722. However, Asterisk 1.4 cannot transcode G722 to some other codec so, you can't have a G722 phone call a G711 phone (unless it does so using G711).
Asterisk 1.6 will, as far as I understand it, support G722 transcoding.
sail V3.1 on the SARK1200 can be installed with either 1.4 or 1.6 of Asterisk.
Kind Regards
S