NAT issue - X lite

Hi,

I have a remote client who is registering his x-lite with my Asterisk 1.2.23. the registration works just fine but he wont be able to receive ZAP call… Client is using a Sonicwall 2040 pro and I’m using PFsense so both the client and asterisk server are behind NAT.

I have 50 other users and it’s working just fine for them except this one client…

on my end, port 5060 and 10,000 to 20,000 are open… I asked the customer to also open port 5060, 5061, 10000 and 20000.

my sip.conf:

[general]
context=default                
bindport=5060                   
bindaddr=0.0.0.0                
srvlookup=yes
disallow=all                  
allow=ulaw
externip = my Asterisk ext ip
localnet=192.168.0.0/255.255.0.0
canreinvite=no


[901407]
type=friend
context=dnc
host=dynamic
username=901407
secret=901407
disallow=all
allow=ulaw
qualify=yes
nat=yes
externip=my Asterisk ext ip

As I mentioned, I got other clients with the same configuration and works just fine…

how can I fix this? is there any setting that I’m missing in Sip.conf

Thanks for your help.