User`s manual

Multi-WAN VPN QoS Router
131
● Dead Peer Detection (DPD): If this option is selected, the connected VPN tunnel will
regularly transmit HELLO/ACK message packet to detect whether there is connection
between the two ends of the VPN tunnel. If one end is disconnected, the device will
disconnect the tunnel automatically and then create new connection. Users can
define the transmission time for each DPD message packet, and the default value is
10 seconds.