PACKET RELAY DEVICE

• US 20080002727A1
• Filed: 08/14/2007
• Published: 01/03/2008
• Est. Priority Date: 03/04/2005
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: YAMANE, Shinji
• Granted Patent: US 7,894,428 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 12/1836 with heterogeneous network architecture
• CPC Class Codes: H04L 12/2803 Home automation networks
• CPC Class Codes: H04L 12/2836 Protocol conversion between an external network and a home network controlling appliance services of a home automation network from a device located outside the home and the home network H04L12/2818; protocol conversion H04L69/08; adaptation of digital video signals for transport over a specific home network H04N7/24
• CPC Class Codes: H04L 12/4604 LAN interconnection over a backbone network, e.g. Internet, Frame Relay
• CPC Class Codes: H04L 41/0893 Assignment of logical groups to network elements

Abstract

Provided is a packet relay device for efficiently transferring a communication packet transmitted from a plurality of terminals connected with a network. The packet relay device is positioned in the network, in which a plurality of local networks are connected with each other through a global network, and at the boundary between the local network and the global network. The packet relay device comprises an acquisition unit for specifying the terminal of a transmission source from a broadcast packet transmitted by the terminal in the local network thereby to acquire group information on the group, to which the specified terminal belongs, a conversion unit for converting the broadcast packet into a virtual multicast packet corresponding to the group information acquired beforehand, a transfer unit for transferring the virtual multicast packet to another corresponding relay device, and a packet conversion unit for converting the virtual multicast packet into a corresponding real broadcast packet.

Claims

1. A packet relay device located at a border between a local network and a global network in a network where a plurality of local networks is connected to each other via the global network, said packet relay device comprising:

a receiving unit receiving a broadcast packet from a terminal within the local network;

an acquisition unit specifying a sender terminal from the broadcast packet and acquiring group information about a group to which the specified sender terminal belongs;

a converting unit converting the broadcast packet into a virtual multicast packet associated with the acquired group information; and

a forwarding unit forwarding the virtual multicast packet toward another relay device connected via the global network and associated with the virtual multicast packet.

2. A packet relay device according to claim 1, further comprising:

a virtual packet receiving unit receiving the virtual multicast packet;

a packet converting unit converting the virtual multicast packet into a real broadcast packet associated with the virtual multicast packet; and

a transmitting unit transmitting the real broadcast packet to within the local network.

3. A packet relay device according to claim 1, wherein the virtual multicast packet is assigned a multicast address as a destination address enabling the another packet relay device located at the border between another local network to which to connect another terminal belonging to the same group as the group to which the specified sender terminal belongs and the global network, to recognize that the virtual multicast packet is a packet into which the broadcast packet for the group has been converted.

4. A packet relay device according to claim 1, wherein said forwarding unit, if said acquisition unit determines that the sender terminal of the broadcast packet does not belong to any group, does not forward the virtual multicast packet to the another relay device.

5. A packet relay device according to claim 2, wherein said packet converting unit includes:

a virtual address extracting unit extracting the virtual multicast address from the virtual multicast packet; and

a virtual address acquisition unit acquiring the real broadcast address associated with the extracted virtual multicast address, and

wherein said transmitting unit, if said virtual address acquisition unit does not acquire the real broadcast address, does not transmit the real broadcast packet to within the local network.

11. A packet relay device according to claim 1, further comprising:

an information transmitting unit transmitting, to the another packet relay device, information about the terminal within the local network to which the self packet relay device is connected, group information about the group to which the terminal belongs, converting information for converting the broadcast packet transmitted from the terminal into a virtual multicast packet associated with the group, and reverse converting information for converting the virtual multicast packet into the real broadcast packet; and

an information updating unit updating the self-retained group information, the self-retained converting information and the self-retained reverse converting information on the basis of the group information, the converting information and the reverse converting information given from said another packet relay device.

6. A packet relay device located at a border between a local network and a global network in a network where a plurality of local networks is connected to each other via the global network, said packet relay device comprising:

a receiving unit receiving a multicast packet from a terminal within the local network;

a packet group acquisition unit acquiring group information associated with the multicast packet;

an acquisition unit specifying a sender terminal from the multicast packet, and acquiring group information about a group to which the specified sender terminal belongs;

a group determining unit determining a destination group from the group information acquired by said packet group acquisition unit and from the group information acquired by said acquisition unit;

a converting unit converting the received multicast packet into a virtual multicast packet associated with the destination group; and

a forwarding unit forwarding the virtual multicast packet toward another relay device connected via the global network and associated with the virtual multicast packet.

7. A packet relay device according to claim 6, further comprising:

a virtual packet receiving unit receiving the virtual multicast packet;

a packet converting unit converting the virtual multicast packet into a real multicast packet associated with the virtual multicast packet; and

a transmitting unit transmitting the real multicast packet to within the local network.

8. A packet relay device according to claim 6, wherein the virtual multicast packet is assigned a multicast address as a destination address enabling the another packet relay device located at the border between another local network to which to connect another terminal belonging to the same group as the group associated with the pre-conversion multicast packet and the global network, to recognize that the virtual multicast packet is a packet into which the multicast packet for the group has been converted.

9. A packet relay device according to claim 6, wherein said forwarding unit, if said group determining unit determines, from the group information acquired by said packet group acquisition unit and from the group information acquired by said acquisition unit, that any coincident group does not exist, does not forward the virtual multicast packet to the another relay device.

10. A packet relay device according to claim 7, wherein said packet converting unit includes:

a virtual address extracting unit extracting the virtual multicast address from the virtual multicast packet; and

a virtual address acquisition unit acquiring the real multicast address associated with the extracted virtual multicast address, and wherein said transmitting unit, if said virtual address acquisition unit does not acquire the real multicast address, does not transmit the real multicast packet to within the local network.

12. A packet relay device according to claim 6, further comprising:

an information transmitting unit transmitting, to the another packet relay device, group information associated with the multicast packet transmitted from the terminal within the local network, second group information about a group to which the terminal belongs, converting information for converting the multicast packet into a virtual multicast packet associated with the destination group, and reverse converting information for converting the virtual multicast packet into the real multicast packet; and

an information updating unit updating the self-retained group information, the self-retained second group information, the self-retained converting information and the self-retained reverse converting information on the basis of the group information, the second group information, the converting information and the reverse converting information given from the another packet relay device.

13. A packet relay method executed by a packet relay device located at a border between a local network and a global network in a network where a plurality of local networks is connected to each other via the global network, said packet relay method comprising the steps of:

receiving a broadcast packet from a terminal within the local network;

specifying a sender terminal from the broadcast packet and acquiring group information about a group to which the specified sender terminal belongs;

converting the broadcast packet into a virtual multicast packet associated with the acquired group information; and

forwarding the virtual multicast packet toward another relay device connected via the global network and associated with the virtual multicast packet.

14. A packet relay method according to claim 13, further comprising the steps of:

receiving the virtual multicast packet;

converting the virtual multicast packet into a real broadcast packet associated with the virtual multicast packet; and

transmitting the real broadcast packet to within the local network.

15. A packet relay method executed by a packet relay device located at a border between a local network and a global network in a network where a plurality of local networks is connected to each other via the global network, said packet relay method comprising the steps of:

receiving a multicast packet from a terminal within the local network;

acquiring group information associated with the multicast packet;

specifying a sender terminal from the multicast packet, and acquiring second group information about a group to which the specified sender terminal belongs;

determining a destination group from the group information and from the second group information;

converting the received multicast packet into a virtual multicast packet associated with the destination group; and

forwarding the virtual multicast packet toward another relay device connected via the global network and associated with the virtual multicast packet.

16. A packet relay method according to claim 15, further comprising the steps of:

receiving the virtual multicast packet;

converting the virtual multicast packet into a real multicast packet associated with the virtual multicast packet; and

transmitting the real multicast packet to within the local network.