Abstract: A packet routing arrangement, when receiving a request to join or leave a multicast group from a host unregistered to that group, a response is sent exclusively to the unregistered host. In the packet routing arrangement, when receiving a request packet from a host to join or leave a group, including the identifier of the group, it is determined whether the source host of the packet is registered to that group; and, if it is not registered, the first group identifier is changed to a second group identifier assigned to another delivery server delivering information to the other unregistered host and the packet is transferred to this other delivery server. When receiving a packet containing certain information from this delivery server, the second group identifier included in the received packet is changed to the first group identifier and the packet is transmitted to the unregistered host.

Abstract: Any or unique VLAN ID is dynamically assigned to a user terminal connected to a network, and communication by the assigned VLAN ID is enabled. A connection request from a user terminal is directed to L2GWs by a tagged VLAN frame having a common VLAN ID on the network. The L2GWs determine whether the connection request can be met, obtain a VLAN ID that can be assigned to the user terminal from a VLAN ID management server, configure themselves to communicate by the assigned VLAN ID, and report the VLAN ID to the user terminal. The user terminal performs subsequent communication by the reported VLAN ID. L2SWs monitor communication between the user terminal and the L2GWs and configure themselves to allow communication between the user terminal and the L2GWs by the VLAN ID assigned to the user terminal.

Abstract: A frame forwarding apparatus is provided with a frame forwarding processing unit for converting a VLAN ID of a frame received from one subscriber terminal into a group VLAN ID and converting a group VLAN ID of a frame received from an ISP router into a subscriber VLAN ID, by referring to a VLAN bundling table. Each of the entries in the bundling table defines subscriber side line information including a line number of a physical line connected to one of the subscriber terminals and a subscriber VLAN ID, in association with a MAC address of the subscriber terminal and ISP router side line information including a line number of a physical line connected to the ISP router and a group VLAN ID.

Abstract: An access network system connected to an ISP network including a subscriber authentication server comprised of a plurality of packet forwarding apparatuses each for connecting user terminals to an Internet network via the ISP network and an address pool management server having an address pool management table for holding, as a sub-address pool, a plurality of IP addresses usable over the ISP network. Each of the packet forwarding apparatuses acquires from the address pool management server an IP address to be allocated to the user terminal having requested connection to the Internet when the subscriber authentication server has succeeded in authentication of the user terminal.

Abstract: A packet transfer apparatus which can switch a communication path for each of a plurality of users using the same L2TP tunnel is provided. Packet transfer apparatuses terminating L2TP contain a table specifying a flow threshold level and a priority level of each subscriber; the amount of packet flow of each subscriber is measured in accordance with the information in the table; if the threshold level is exceeded, the packet communication path is switched in accordance with the priority level specified for each subscriber. The OSPF protocol is used to manage the path information, and the information of a plurality of paths to a destination is stored in a path management table. The path is switched by specifying destination routers with the source routing option in the IP header of a packet after L2TP encapsulation.

Abstract: A Layer 2 switch manages distribution destinations of a multicast packet and distributes a copy of the multicast packet, so that the bandwidth wasted in a network is reduced. The Layer 2 switch is disposed between a user terminal and a packet transfer apparatus, which are connected by P2P, has a function to manage connected multicast users, receives a multicast packet on behalf of the users, and distributes a copy, to reduce the bandwidth wasted between the Layer 2 switch and the packet transfer apparatus.

Abstract: An LAC manages multicast destinations, and forms and distributes copies of the multicast packets. An L2TP tunnel and an L2TP session are formed between LAC 1-i and LNS 2-i, and LNS 2-i is connected to network NW2 such as the Internet. Data is transferred between a subscriber and the network through the L2TP connection. LNS 2-i and sever S1 are connected through network NW2 which has routers. A packet transfer apparatus enables LAC 1-i to manage subscriber information and to form and distribute copies of the packets to the subscribers when server S1 on network NW2 distributes multicast packets of a program or the like to the subscribers.

Abstract: A frame forwarding apparatus connected between an ISP router and a plurality of subscriber terminals comprises a frame forwarding processing unit and a VLAN bundling table defining the correspondence of subscriber side line information with ISP router side line information and subscriber terminal's MAC address. The subscriber side line information includes a physical line number and a subscriber VLAN identifier, and the ISP router side line information includes a physical line number connected to the ISP router and a group VLAN identifier. By referring to the VLAN bundling table, the frame forwarding processing unit operates to convert a VLAN identifier given in a frame received from a subscriber terminal into a group VLAN identifier and to convert a VLAN identifier given in a frame received from the ISP router into a subscriber VLAN identifier, before forwarding the frame to its destination.

Abstract: An IP address provision request issued from a client terminal according to the DHCP protocol is transferred to a DHCP server, and an application for provision of an IP address is received. At this time, a packet transfer system stores pieces of information on the client terminal (IP address and MAC address) in a memory unit. Moreover, the client terminal or the packet transfer system itself broadcasts an ARP request. Pieces of information on the client terminal (IP address and MAC address) contained in an ARP packet are also stored in the memory unit. If the stored IP addresses contained in the DHCP and ARP packets respectively agree with each other, packets addressed to the client terminal that has transmitted the ARP packet are filtered in order to decide whether the packets are allowed to pass through the port.

Abstract: Any or unique VLAN ID is dynamically assigned to a user terminal connected to a network, and communication by the assigned VLAN ID is enabled. A connection request from a user terminal is directed to L2GWs by a tagged VLAN frame having a common VLAN ID on the network. The L2GWs determine whether the connection request can be met, obtain a VLAN ID that can be assigned to the user terminal from a VLAN ID management server, configure themselves to communicate by the assigned VLAN ID, and report the VLAN ID to the user terminal. The user terminal performs subsequent communication by the reported VLAN ID. L2SWs monitor communication between the user terminal and the L2GWs and configure themselves to allow communication between the user terminal and the L2GWs by the VLAN ID assigned to the user terminal.

Abstract: A Layer 2 switch manages distribution destinations of a multicast packet and distributes a copy of the multicast packet, so that the bandwidth wasted in a network is reduced. The Layer 2 switch is disposed between a user terminal and a packet transfer apparatus, which are connected by P2P, has a function to manage connected multicast users, receives a multicast packet on behalf of the users, and distributes a copy, to reduce the bandwidth wasted between the Layer 2 switch and the packet transfer apparatus.

Abstract: An access network system connected to an ISP network including a subscriber authentication server comprised of a plurality of packet forwarding apparatuses each for connecting user terminals to an Internet network via the ISP network and an address pool management server having an address pool management table for holding, as a sub-address pool, a plurality of IP addresses usable over the ISP network. Each of the packet forwarding apparatuses acquires from the address pool management server an IP address to be allocated to the user terminal having requested connection to the Internet when the subscriber authentication server has succeeded in authentication of the user terminal.

Abstract: Upon receiving a connection request from a terminal, a packet transfer apparatus registers information on the terminal with a memory and forwards information necessary for the authentication of the terminal and an authentication request to an authentication server. The apparatus then receives authentication permission and a multicast group address list associated with the terminal that has made the connection request from the server. The apparatus then associates the multicast group address list received with the terminal information stored in the memory for registration. Upon receiving a participation request from the terminal, the apparatus determines whether or not the group address contained in the participation request is present in the list in the memory. If the group address is present in the list in the memory, the apparatus permits the delivery of a packet to the terminal from a content delivery server and transmits the packet to the terminal.

Abstract: A packet transfer apparatus for accommodating a plurality of hosts to transfer packets between the plurality of hosts and an ISP network. Upon receipt of a connection authentication request from a host, the packet transfer apparatus transmits ID and password information (information required for authentication) included in the request to an authentication server in the ISP network, acquires IP address information for the host from the authentication server, and notifies a DNS server in the ISP network of the IP address information, and previously registered domain name information of the host.

Abstract: A packet routing arrangement, when receiving a request to join or leave a multicast group from a host unregistered to that group, a response is sent exclusively to the unregistered host. In the packet routing arrangement, when receiving request packet from a host to join or leave a group, including the identifier of the group, it is determined whether the source host of the packet is registered to that group; and, if it is not registered, the first group identifier is changed to a second group identifier assigned to another delivery server delivering information to the other unregistered host and the packet is transferred to this other delivery server. When receiving a packet containing certain information from this delivery server, the second group identifier included in the received packet is changed to the first group identifier and the packet is transmitted to the unregistered host.

Abstract: A packet transfer apparatus which can switch a communication path for each of a plurality of users using the same L2TP tunnel is provided. Packet transfer apparatuses terminating L2TP contain a table specifying a flow threshold level and a priority level of each subscriber; the amount of packet flow of each subscriber is measured in accordance with the information in the table; if the threshold level is exceeded, the packet communication path is switched in accordance with the priority level specified for each subscriber. The OSPF protocol is used to manage the path information, and the information of a plurality of paths to a destination is stored in a path management table. The path is switched by specifying destination routers with the source routing option in the IP header of a packet after L2TP encapsulation.

Abstract: An LAC manages multicast destinations, and forms and distributes copies of the multicast packets. An L2TP tunnel and an L2TP session are formed between LAC 1-i and LNS 2-i, and LNS 2-i is connected to network NW2 such as the Internet. Data is transferred between a subscriber and the network through the L2TP connection. LNS 2-i and sever S1 are connected through network NW2 which has routers. A packet transfer apparatus enables LAC 1-i to manage subscriber information and to form and distribute copies of the packets to the subscribers when server S1 on network NW2 distributes multicast packets of a program or the like to the subscribers.