T20P - After configuring Forward, the phone doesn't receive calls!

[ruiseixas]

Hi,

After checking the router NAT and PAT, and try to register my account from different devices at the same time, I concluded that the account that always missed the receiving calls, was due to the fact that the SIP provider in question only allows one device registration at time! Contrary to OnSIP, VoIP SAPO has this restriction...

The phone works well, and it maintains the register if I don't register with other device to the same account.

Thanks for your replies.

Regards,
Rui

PS: My phone version:

Code:

Firmware Version           9.70.0.140  
Hardware Version           7.0.1.61