From VoIP.ms Wiki
The GXP1630 delivers an effective communications platform for access to quick call control. Delivering a vibrant and clear user-interface, this device is a perfect solution for those who handle low to medium call volume and require access to key call efficiency functionalities.
Once you have connected your device to your local connection, it will be necessary to obtain the local IP address that was designated for it.
-From your IP phone navigate through the menus to obtain its IP address:
Menu >> Status >> Network Status >> IPv4 Address
-Now that you have the Local IP address, open it in your web browser of preference.
-Once you have opened the login page, use the following credentials to access to the configuration:
-Once you see the settings page, go to the following:
Account >> Account # >> General Settings
-Change the following settings according to the information of your account:
A. Account Name: The name for this account that will be displayed on the LCD screen of your phone.
B. SIP Server: The server that you will use for the registration of this device. (one of VoIP.ms multiple servers, you can choose the one closest to your location.)
Notice that it is necessary to use the same server for both the device and the DID number in order to get incoming calls correctly
C. SIP User ID: The account or sub-account number that you will be using for this line.
D. Authenticate Password: The password for the account or sub-account you will be using for this line.
E. Name: The name that will be used as Caller-ID Name. (See the requirements below.)
IMPORTANT for Name: - We suggest entering your outbound Caller ID Name must be in capital letters. This will appears more clearly/visible on some devices. - You must NOT use any special characters, they will not be displayed. - Enter a max of 15 characters. Some of regular Canadian providers will not show more than 15 characters max. We suggest shrinking or adapt your caller ID. - Spaces are allowed in a caller id name.
F. Save and Apply
Basic SIP settings
Once this is done, we will need to set the time that the device will send the information for its registration status.
-Please go to the following:
Account # >> SIP Settings >> Basic Settings
- Change the following:
SIP Registration: Yes
Register Expiration: 5 (this is in minutes)
Enable OPTIONS Keep Alive: Yes
SIP Transport: UDP or TCP
Finally, click Save and Apply
Outgoing calls issue
If you are able to receive incoming calls but outgoing calls are failing with error "No response", make the following changes to fix it:
1. Login into your device's settings and head to Accounts > Account X > SIP > Custom SIP Header and disable:
- Use X-Grandstream-PBX Header
- Use P-Access-Network-Info Header
- Use P-Emergency-Info Header
2. Go to Accounts > Account X > SIP > Audio Settings, and choose codec G729A/B as preferred Vocoder and the rest with PCMU.
In the event where you need the guides directly from Grandstream, you may find the user and admin manual guides below:
User Manual : 
Admin Manual :