Phone numbers
To make and receive calls, you need to have a phone number attached to your application.
How to get a phone number
To buy a phone number, log in to your Voximplant control panel and select the Numbers section from the main menu:

In the left upper corner, choose Buy a new phone number:

This opens a list of availible phone numbers to buy.
You can choose between real phone numbers and test ones, specify the desired phone number country, state, and city:

Test phone numbers are good for testing apps and developers. To call a test phone number, you need to call one of Voximplant inner numbers and enter the test number as an extention.
You cannot use a test phone number as your Caller ID.
Once you buy a phone number, you can attach it to your application and use.
How to attach a phone number to an application
To attach a number to your application, go to the Applications section in your control panel, choose the necessary application and switch to the Numbers tab. Choose an available number and click Attach:

You can choose a routing rule while attaching the number, or you can do it later manually.

You can buy several numbers and bind them to several routing rules to process the numbers in different ways.
Once you attach a phone number to your application, you can make and receive calls.