Sip --> h323 gateway No voice

I have been reading about the no voice issue and the more I read, the more I get confused because I am not sure the issue is related to NAT (that I am not using in my setup), to canreinvite, or to missing configuration.

My setup is as follows:

softphone connecting to sip:

sip.conf

[general]
context = default
allowoverlap = no
bindport = 5060
bindaddr = 0.0.0.0
allow=ulaw,alaw

[1000]
type=friend
username=ilmixu
secret=1234
host=dynamic
context=internal-uc
rfc2833compensate=yes
dtmfmode=rfc2833
allow=all

h323.conf

[general]
;mediawaitforconnect=yes
port=1720

[mygateway]
type=peer
host=xx.xx.xx.xx my alcatel ip
nat=no
context=internal-uc
disallow=all
allow=alaw
allow=ulaw

extensions.conf

[general]
static = yes
writeprotect = no
autofallthrough = yes
clearglobalvars = no
priorityjumping = no

[internal]
plancomment = MyPlan
;exten => s,1,Wait(1)
exten => s,n,Answer
exten => _XXXX,1,Dial,SIP/${EXTEN} ;to call on my openfire
exten => _XXXX,2,Dial,H323/${EXTEN}@mygateway
exten => #,n,Hangup^M

The calls are routed properly, but when we pickup the phone, there softphone receives the status (pickup phone) after about 3 seconds, and there is no voice.

Can anyone help?