Check if g729 codec is being used

Hello,

I installed the g729 codec (downloaded,registered,placed in modules folder , loaded from asterisk CLI ) on my pbx , than from freepbx gui did the following:
1)Under SIP settings I enabled and dragged the g729 codec in 1st position
2)In every trunk I appended the lines in the peer details textarea:
disallow=all
allow=g729&gsm&alaw

Now I want to make sure that the codec was actually being used , so , while I was on a call , I performed the ‘sip show channels’ command but I didn’t get any information about the codec ! Here is a screenshot

What do you think is happening?

core show channels

Sorry but even with core show channels I don’t get that info:
here’s the screenshot of core show channels