Hitachi, Ltd.

Sunao Sawada

Shinji Nozaki

Hidemitsu Higuchi

Kazuaki Tsuchiya

Tatsuya Watanuki

Tetsuo Oura

Takahisa Miyamoto

Yoshikazu Tominaga

Ken Watanabe

Akihiro Ebina

A communications apparatus for converting an IPv4 multicast packet transmit from an IPv4 terminal into an IPv6 multicast packet and transmitting the converted IPv6 multicast packet to one of a plurality of IPv6 networks. The communications apparatus has information indicating to which IPv6 network the IPv4 multicast packet to undergo conversion processing is to be transmitted. The communications apparatus then converts the received IPv4 multicast packet into an multicast packet and transmits the converted IPv6 multicast packet to an IPv6 network where it is required to be sent.

Multicast routing method and apparatus for routing multicast packet

A mobile node moves from a first IP (Internet Protocol) network to a second IP network in a network system in which the first IP network capable of executing communication in accordance with both first and second kinds of IPs and the second IP network capable of executing communication in accordance with only the first kind of IP are connected with each other. When the mobile node communicates a message with other nodes on the first network after its movement accordance with the second kind of IP, a header for the movement containing both home and foreign addresses of the first kind in IP is added to a header containing home and foreign addresses in the second kind of IP, and put to the message, is added. The message to which the movement header is thus added is used for the communication between a first mobile agent on the first network and a second mobile agent on the second network, or between the mobile node and the first mobile agent.

Mobile node, mobile agent and network system

A multicast communication method for allowing a communication control apparatus for communicating in accordance with IPv4 to communicate with a communication control apparatus for communicating in accordance with IPv6. This method includes the steps of: when an IPv4 multicast packet is inputted, discriminating that this packet is a data packet on the basis of an IPv4 header; when it is determined that the packet is the data packet, converting the IPv4 header of the IPv4 multicast packet into an IPv6 header; generating an IPv6 multicast packet; and outputting the generated IPv6 multicast packet to a IPv6 network.

Multicast communication method

A communications apparatus for converting an IPv4 multicast packet transmit form an IPv4 terminal into an IPv6 multicast packet and transmitting the converted IPv6 multicast packet to one of a plurality of IPv6 networks. The communications apparatus has information indicating to which IPv6 network the IPv4 multicast packet to undergo conversion processing is to be transmitted. The communications apparatus then converts the received IPv4 multicast packet into an IPv6 multicast packet and transmits the converted IPv6 multicast packet to an IPv6 network where it is required to be sent.

A communications apparatus for converting an IPv4 multicast packet transmit from an IPv4 terminal into an IPv6 multicast packet and transmitting the converted IPv6 multicast packet to one of a plurality of IPv6 networks. The communications apparatus has information indicating to which IPv6 network the IPv4 multicast packet to undergo conversion processing is to be transmitted. The communications apparatus then converts the received IPv4 multicast packet into an IPv6 multicast packet and transmits the converted IPv6 multicast packet to an IPv6 network where it is required to be sent.

A communication unit is connected to both an IPv4 network and an IPv6 network for converting an IPv4 multicast packet into an IPv6 multicast packet. The communication unit, which has held the IPv6 multicast addresses, holds the IPv4 multicast addresses of a multicast group on the IPv4 network and the held IPv6 multicast addresses in correspondence with each other. Moreover, the communication unit converts the IPv4 multicast address of the received IPv4 multicast packet into the IPv6 multicast address held in correspondence with the IPv4 multicast address, then transmits the multicast packet to the IPv6 network.

Multicast routing method and an apparatus for routing a multicast packet

A network in which a plurality of network apparatuses are mutually connected. The network has at least one internetwork forwarding apparatus which connects an external network and the network. The internetwork forwarding apparatus automatically allocates addresses to the plurality of network apparatuses connected to the network. Names of the network apparatuses, the addresses automatically allocated to the network apparatuses, and types of the network apparatuses are recorded into a nonvolatile storage medium. A filtering rule of a network packet of the internetwork forwarding apparatus are automatically created on the basis of recorded information.

Address autoconfiguration method for home network

In an information network having a complex structure made of a logical network and also a physical network, such an information network is constituted so as to realize a multicast service capable of not increasing an amount of a network traffic larger than a necessary traffic amount. This information network contains a plurality of information relay apparatuses for relaying information among a plurality of VLANs (Virtual Local Area Networks), a network for connecting these information replay apparatuses to each other, a multicast server and a plurality of terminals, belonging to an arbitrary VLAN of these VLANs. A multicast relay processing unit, a multicast address learning processing unit, and a multicast learning table are provided in each of these information relay apparatuses so as to register a predetermined relay destination of a multicast communication. Even in such a case that the VLAN structure is made complex irrespective of the physical network structure, it is possible to distribute such a multicast packet suitable for the physical network structure.

Network relay apparatus

A packet communications apparatus of the present invention essentially comprises a plurality of network interfaces (NIFs), a learned address table, a packet forwarding unit (PFU) and a processor for directive packets to change state (PDPCS). The learned address table contains information for identifying a NIF through which to send a packet. The PFU selects a port through which to forward a packet by referring to the learned address table, according to the state of the NIFs, and forwards or discards a packet received from a user terminal. The PDPCS receives a packet including a directive to change the state of a specific NIF to one of the connected state, disconnected state and stateless. The PDPCS changes the state of the specific NIF to one of the connected state, disconnected state and stateless, according to the directive in the packet.

Communication apparatus for routing or discarding a packet sent from a user terminal

A communicating apparatus is disclosed which has been connected to both of the IPv4 network and the IPv6 network for converting an IPv4 multicast packet into an IPv6 multicast packet. The communicating apparatus, which has held the IPv6 multicast addresses, holds the IPv4 multicast addresses of a multicast group on the IPv4 network and the held IPv6 multicast addresses in correspondence with each other, said communicating apparatus having been a member of said multicast group. Moreover, the communicating apparatus converts the IPv4 multicast address of the received IPv4 multicast packet into the IPv6 multicast address held in correspondence with the IPv4 multicast address, then transmitting the multicast packet to the IPv6 network.

Growing community of inventors

Yokohama, Japan

Sunao Sawada