Draytek VIGOR2860 series User Manual page 344

Available settings are explained as follows:
Item
Profile Name
VPN Dial-Out Through
328
Description
Type a name for such profile. The length of the file is limited
to 10 characters.
Use the drop down menu to choose a proper WAN interface
for this profile. This setting is useful for dial-out only.
Or,
Vigor2860 Series User's Guide