Vono VoIp server incoming call problem

I’m using Asterisk netsec 1.2.2 on Suse 10.0 with an X-Lite soft phone which registers with Asterisk on this machine. I used this phone to test the PBX and I made an AIX configuration with voipjet which worked fine for placing calls to regular land lines. This particular mchine is directly conected to the internet with a firewalll that blocks all incoming traffic and lets all outgoing traffic through. I am using the soft phone on the same machine.

I created an account with a voip service in Brazil called VONO which is a sip solution working like SkypeIn/SkypeOut. In other words I have a Sao Paulo phone number that will ring on a voip phone. If I call this VONO number I can get Asterisk to make the soft phone ring but as soon as I answer, it hangs up with this message on the Asterisk terminal:

Had to drop call because I couldn’t make SIP/user-d095 compatible with SIP/john-7587

“john” is my soft phone extension

This is what sip.conf has:

[general]
port = 5060
bindaddr = 0.0.0.0
context = internal

register = user:pass@vono.net.br:1571

[john]
type=friend
secret=password
qualify=yes
nat=no
host=dynamic

[vono]
type=peer
username=user
secret=pass
fromuser=user
fromdomain=vono.net.br
disallow=all
allow=g729
host=vono.net.br
insecure=very
qualify=yes
port=5060
auth=md5
nat=yes
reinvite=no
dtmfmode=rfc2833
context=recebe_vono

and this is in extensions.conf:

[internal]
exten => 100,1,Dial(SIP/john)
exten => 611,1,Echo()

[ligacao_vono]
exten => _0XX.,1,Dial(SIP/${EXTEN}@vono,50,r)

[recebe_vono]
exten => _.,1,Dial(SIP/john,20,r)

What does this error message mean? How can I correct it?

Thanks.

In case this can be of use to anyone, I found that the problem is with the codecs so I removed the restrictions and the list of allowable codecs. This is the SIP.CONF and EXTENSIONS.CONF files I use that allows me to make and receive calls.

SIP.CONF
[general]
port = 5060
bindaddr = 0.0.0.0
context = default
srvlookup = yes

[vono]
type=friend
username=user
secret=pass
fromuser=user
fromdomain=vono.net.br
host=vono.net.br
insecure=very
qualify=yes
port=5060
auth=md5
nat=no

reinvite=no
dtmfmode=rfc2833
context=vono-in

EXTENSIONS.CONF

[vono-out]
exten => _8.,1,Dial(SIP/${EXTEN:1}@vono,50,r)

[vono-in]
exten => _.,1,Dial(SIP/miguel,10,r)