The phone numbers tab (as below) enables the administrator to see the following:

1. The number of each PBX user.

2. The name of each PBX user. 

3. The extension of each PBX user.

4. The call flow applying to each PBX user.

Additionally, the admin can do the following from this page:

1) add extensions 

2) click on the icons below to a) delete phone numbers, configure call flows, Configure inbound reporting, configure phone numbers and edit extensions.

For more detailed information, please see the Customer Setup Section