[Spce-user] Sip-client behind nat shows internal IP in sipwise

[Ks]

Dear friends,

I am new at sipwise. I installed the appliance on a fresh debian server 
an I can register clients.
The sipwise server is on a official IP and lients behind nat routers.
If I register the client sipwise shows internal ip address on 
registraion and calling is not possible
User Agent:
Linksys/SPA962-6.1.5(a)
Contact
sip:11588 at 10.11.70.2:5063
NAT
yes
Expires
2013-09-02 11:53:30


How can I change that sipwise is using the external IP from Nat router?

Best Regards
Sonny