You will need to log in all the room’s extension numbers first to properly manage the room calls. You need to activate the call logging feature from the Rental and Display Options for performing call accounting operations. Follow the steps below to add the extensions.

1. From the Rooms menu, select the Extension Master. The Extension Master form gets displayed.
2. Click on Add. The Add Extension form gets displayed.   
3. Select the appropriate option whether you would like to generate the extension range or specific extension.
   1. If you go for the Range option, you need to specify the From and To range. Specify the range by how much should the extension increment in the Steps edit box.
   2. If you go for the Specific Extension, you need to specify the extension in the edit box. If you have more than one extension, specify the extensions separated by commas

   Note: Note that the extensions are added to the Extensions list.

4. Click OK to close the Extension Master form.