DID question

Hi,

I bough a USA DID, but when 1 talk, is like the other end is Mute. I can hear the other side background, then when I stop of talking I can hear the other side background sounds…

Does is that normal?

I’m using SIP:

[mytrunk]
type=peer
nat=auto
dtmfmode=rfc2833
disallow=all
context=from-did
canreinvite=yes
allow=alaw,ulaw,gsm
directmedia=yes
host=provider-ip