Techniques are described to automatically activate and deactivate standby backup paths in response to changing bandwidth requirements in an adaptive private network (APN). The APN includes one or more regular active wide area network (WAN) links in an active mode and an on-demand WAN link in a standby mode. The on-demand WAN link is activated to supplement the conduit bandwidth when an available bandwidth of the conduit falls below a pre-specified trigger bandwidth threshold and the conduit bandwidth usage exceeds a usage threshold of a bandwidth of the conduit that is being supplied by the active paths (BWc). The on-demand WAN link is deactivated to standby mode when an available bandwidth of the conduit is above the pre-specified trigger bandwidth threshold and the conduit bandwidth usage drops below the usage threshold of BWc techniques for adaptive and active bandwidth testing of WAN links in an APN are also described.