IP Phone can't call via Asterisk+Nokia22

Hello,

I have an Asterisk 1.2.9.1 (patched with bristuff) with 2 cards: 1 TDM400P with 2 FXO, and 1 QuadBRI. The extensions are IP Phones (SIP and IAX2), and PAP2. In the TDM400P I have 2 GSM Nokia 22.

  • An analog phone conected to a PAP2 can make calls via the Nokia 22. No noise, no echo. All ok.

  • An IP Phone can’t make calls via the Nokia22: sometimes there is only noise, and sometimes the called person listen to himself with a lot of echo (without hearing the person that originate the call)

My zapata.conf (only the GSM channels):

signalling=fxs_ks
busydetect=yes
busycount=7
language=es
context=from-pstn
callwaiting=yes
callwaitingcallerid=yes
threewaycalling=yes
transfer=yes
cancallforward=yes
callreturn=yes
echocancel=yes
echocancelwhenbridged=yes
echotraining=800
callerid=asreceived
callgroup=1
pickupgroup=1
group=1
channel=>15-16

What can I do to solve this problem? Thanks in advance.