[Freeswitch-users] Possible to disable core codecs?

Hello, Is there a way to disable core codecs offered by CORE_PCM_MODULE? I want to use G729 as I need to make more concurrent calls with limited bandwidth. But no matter what I do, system keeps using PCMU codec. I did following modifications based on the wiki but nothing seems to work. In modules.conf.xml, <load module="mod_g729"/> Under SIP profile file, <param name="inbound-codec-negotiation" value="greedy"/> Under vars.xml file, <X-PRE-PROCESS cmd="set" data="global_codec_prefs=G729"/> <X-PRE-PROCESS cmd="set" data="outbound_codec_prefs=G729"/> I also contacted my SIP provider (Vitelity) but they say if I disable other codecs completely, I may be able to use G729. Thanks for help. Malay Thakershi