Is there some status indicator on the nodephone side to tell you that the 7912 is registering?Have you taken the Astaro totally out of the equation?
To get the time and date working ask google and NTP servers and find one close to you, this is what i did.
As for the DNS if you can put all that info into the phone manually it should clear it up.
At present the phone is stuck in a "Registering" state and the following items are logged in Status Messages: Error Updating Locale Error Updating Locale DNS Unknown Host DNS Unknown Host On researching the "Error Updating Locale" error I found the following: --------------8 Believe beneboi mentioned a similar issue on a 7975 that however went away once his NAT traversal and port forwarding were sorted. t=1390896 Assuming 7911 has settings for those, what is the voipcontrolport set to? t=1390896&p=6#r113 Have never configed a 7911 SIP, can you post the config minus personal details? This may give you an idea when applied to your 7911 /forum-replies.cfm?
Assuming 7911 has settings for those, what is the voipcontrolport set to? t=1390896&p=6#r113Configuring a Cisco 7911 IP phone to my Node Phone service.
This then allows your external IP address to be registered as the IP address that your phone is on.