Grandstream GXP2120 IP Phone
From VoIP.ms Wiki
You must first determine what IP address the IP Phone was assigned. To do this, press the round menu button, then the down arrow next to it until the display shows:
 IP Addr
Now, press the round menu button again and you will be shown the IP address of your device (e.g. 192.168.0.100).
Open your web browser and go to the IP you just found: https://[DeviceIP]
You will be prompted to enter a password, the default is "admin", then click the "Login" button.
Click on ACCOUNT, followed by the ACCOUNT 1 (to configure your line 1). You need to modify only a few settings from the factory default.
Fill in the followings fields.
- SIP Server: atlanta.voip.ms (You can enter the address of any of our multiple servers, this is just an sample with Atlanta server)
- SIP User ID: 100000 (Replace with your VoIP.ms username, it is a six digit number)
- Authenticate Password: ********* (Type your VoIP.ms account Password)
- SIP Registration: Yes
- Register Expiration: 5
Finally, please click the Update button and then Reboot at the bottom of the configuration screen.
If you receive Weird Calls such as from CallerID 100 or in the middle of the Night not showing in your CDR, please note that these calls are not going through our Network but rather through the internet directly to your IP Phone without authentication.
Users have the ability to deny calls that are not authenticated. You can find the option by navigating the phone web interface, clicking on Account X-->SIP Settings-->Security Settings and enabling "Authenticate Incoming invite" You can also go to Account X -> SIP Settings -> Security Settings -> and enable "Accept Incoming SIP from Proxy Only"