should be left as default unless advised otherwise.
The default value here is G.711_PT and where WAN bandwidth is
not an issue we recommend that this is left.
If you have a requirement to use G.729 as the preferred codec then
the G.729_PT or G.729_Fix profiles should be considered.
The G.729_PT profile will place G729 as the first choice codec in a
list of possible options meaning that G729 should be negotiation in
most call scenarios but is not guaranteed, this profile offers the best
compatibility with other SIP devices.
The G.729_Fix profile will only allow the use of G729 for calls but
reduces the systems compatibility with other SIP devices that do
not support G729.