Hitachi Communication Technologies, Ltd.

Hitachi, Ltd.

Migaku Ota

Hiroaki Miyata

Jun Nakajima

Yoshitaka Sakamoto

Koji Ikeda

Masahiro Kimura

Daiki Nozue

Shinsuke Shimizu

Minoru Nagai

Kengo Ijima

Hisao Taguchi

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.

Multicast packet routing arrangements for group-membership handling

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.

Dynamic VLAN ID assignment and packet transfer apparatus

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.

Frame forwarding apparatus for converting VLAN identifiers

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.

Packet forwarding apparatus and access network system

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.

Packet transfer apparatus

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.

Layer 2 switch

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-and LNS-, and LNS-is connected to network NWsuch as the Internet. Data is transferred between a subscriber and the network through the L2TP connection. LNS-and sever Sare connected through network NWwhich has routers. A packet transfer apparatus enables LAC-to manage subscriber information and to form and distribute copies of the packets to the subscribers when server Son network NWdistributes multicast packets of a program or the like to the subscribers.

Growing community of inventors

Yokohama, Japan

Migaku Ota