Draytek Vigor2762 series User Manual page 66

Item
After finished the above settings, click OK to save the settings.
56
Description

WAN Failure – When the active WAN failed, such WAN
will be activated as the main network connection.

Traffic Threshold – When the data traffic of active
WAN reaches the traffic threshold (specified here), the
failover WAN will be enabled automatically to share
the overloaded data traffic.
Vigor2762 Series User's Guide