The Caller ID Number under Outbound Call Preferences is what OnSIP sends out as the caller-ID when an outbound call is placed. On calls to the PSTN, ONLY the number is accepted by the outbound carrier. As long as you see the caller-ID number, you have setup caller-ID correctly. The Caller-ID name field is only sent on SIP to SIP (extension to extension) phone calls.
First, log in to the OnSIP Admin Portal and navigate to the Users tab. Click on the name of the user who's Caller ID you'd like to modify and look for the Outbound Call Preferences section.
Click "modify" to change this user's settings. You can either have the user's phone send Caller ID (Please note: not all phones can send caller-ID settings), or provide a custom one through our interface. For custom Caller ID, select "custom" as the PSTN Caller ID, and fill in the name and phone number you would like to appear as Caller ID. The custom setting will then over-ride anything sent by the phone.
When you're done, click "save". If everything went okay, you should see your settings in the Outbound Call Preferences section. Otherwise you will be given an error message and asked to fix what went wrong.
On all extension to extension calls, both your name and number will be displayed to the called party. On calls to the PSTN, most carriers will drop the caller-ID name, but will display the caller-ID number, given the number is a valid 11 digit number.
Setting Default Caller ID click here
Can't Call Toll Free Numbers:
If you have problems calling toll free numbers, it may be a problem with your outbound caller-ID number. Make sure that your caller-ID number is a valid 11 digit phone number and not, itself, a toll free number. Many toll-free numbers reject calls without a valid caller-ID or if the caller-ID is a toll-free number.