A PPP termination device allowing PPP termination at a location where a decreased number of subscriber's signals are multiplexed is disclosed. The PPP termination is performed in an access gateway including a switch in the access network system. The access gateway includes a first interface to a DSLAM, a second interface to a backbone network, and a header processor for converting between a network-layer packet and a PPP data packet including the network-layer packet. The switch switches a connection among the first interface, the second interface, the PPP link controller, and the header processor, depending on which one of a PPP data packet and a link control packet is inputted. The link control packet is used for link establishment and disconnection.