Draytek VigorPro 5300 User Manual page 21

NT mode in VoIP>> Phone Settings, the orange LED will light on to indicate ISDN2-S0 is
selected. And by using ISDN phone adapters (coming from the router package), the user can
connect several phones to Vigor5300VS for communication. Refer to the following figure
for reference.
Yet, if the user configures ISDN S0 2 as TE Mode in VoIP>> Phone Settings, the green
LED will light on to indicate ISDN2-TE is selected. Then, the port is specified for ISDN
line only. Refer to the following figure for reference.
(For the detailed information of LED status, please refer to section 1.2.)
VigorPro5300 Series User's Guide 13