[cisco-voip] cme 3.2.1. and g.711 to G.729 Codec

[wmartinoglio at asp.it]

Hi all,
i've a problem.
how i can to change the codec to G.729 from G.711 for ADSL connections in
the following scenario?

a) CCME 3.2.1 installed on a 2610XM at central office, linked to a PBX
Alcatel Omnipcx 4400 via ISDN BRI. Central office use Cisco switches and
routers, like 36xx and 26xx
b) 1 7905G IP phone on Lan at central office
c) 1 7905G IP phone on WAN in a branch office linked to the central office
via ADSL 64Kbps(other branch at 128 Kbps). the branch offics use 26xx or
cisco 837 router for connections to central office.

the 2 IP phone use the following firmware: CP7905040000SCCP040701A.sbin

this configuration use 80 Kbps, of course G.711. How i can switch to G.729
for these WAN connections?
thank you in advance
auker