The customer at Ext. 10 (as long as they are on the handset, not the speakerphone), can enter the programming mode while speaking with you, becoming your eyes and fingers. You just have to remember the programming codes to step them through. There was at one time a device that allowed remote access of Ext. 10 for programming, an of course the Dial-up GUI that usually wouldn't connect to the modem in the Backup/Restore/Remote Access card.