sip trunk problem?

[alcatelboy]

i can use the elastix's sip trunk to connect a the other sip gateway,it's config see below:
host=hk1-sip01.aoillphost.com
username=18001160011
secret=6GSRLPPAa
type=peer
qualify=yes
canreinvite=yes
port=5060
nat=yes
dtmfmode=rfc2833
insecure=very
context=custom-zutlus
;context=custom-rodge-zutlus
fromuser=18001160011

but i use the config ,the oxe can't to connect?
why?
the oxe config :

Node Number (reserved) : 1 |
| Instance (reserved) : 1 |
| Instance : 0 |
| |
| Gateway Name : custom-zutlus |
| Remote domain : hk1-sip01.aoillphost.com |
| PCS IP address : ----------------------------------------------- |
| Port number : 5060 |
| Transport type + TCP |
| RFC3262 forced use + False |
| Belonging domain : node000000 |
| Registration Id : -------------------------------------------------- |
| ation ID in P_Asserted + False |
| Registration timer : 0 |
| Outbound Proxy : hk1-sip01.aoillphost.com |
| Supervision timer : 0 |
| Trunk group number : 100 |
| Pool Number : -1 |
| Outgoing realm : aoipdial |
| Outgoing username : 18001160011 |
|

oxe trace error number is 480.
oxe can't to support the NAT?
somebody can help me .

[cavagnaro]

SIP is not NAT friendly...please search on the forum for similar issues and solutions proposed