C450IP does not ring on incoming calls.

[pranzo]

I have this problem using C450IP with VoXaLot.
The SIP registration went successfully. The echo test was OK.
But the phone does not ring on incoming calls sent to: sip:mynumber@voxalot.com.
The strange thing is that if I launch SJphone (registered at VoXaLot) on my pc, then incoming calls ring both on SJPhone and on C450IP.

I suppose that my configuration of C450IP is partly not correct or incomplete.
Can you help me?

I have tried many combinations. The last one is:

Authenticated name: mynumber
Authenticated password: mypassword
Confirm authenticated password: thesameasabove
Username: mynumber
Domain: eu.voxalot.com
Displayed name: myname
Proxy Server: eu.voxalot.com
Proxy Server port: 5060
Registrar Server: eu.voxalot.com
Registar Server Port: 5060
SIP Port: 5060
RTP Port: 5004
Random Port: No
Use Stun: yes
STUN Server: stun.voxalot.com
STUN Port: 3478
NAT Refresh Period: 20 sec
Proxy Outbound mode: never
Outbond Proxy: eu.voxalot.com
Outbond Proxy Port: 5060
VoIP Volume: normal
Use Annex B for G729: No
Select codecs: G729, G711 a law, G711 m law, G726