PACKET TRANSFER DEVICE

• US 20110091212A1
• Filed: 11/27/2008
• Published: 04/21/2011
• Est. Priority Date: 04/25/2008
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nonaka, Naomichi
• Granted Patent: US 8,687,644 B2
• Time in Patent Office: Days
• US Class Current: 398/66
• CPC Class Codes: H04J 14/0201 Add-and-drop multiplexing
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/022 For interconnection of WDM optical networks
• CPC Class Codes: H04J 14/0254 Optical medium access
• CPC Class Codes: H04J 14/0275 using an optical service channel
• CPC Class Codes: H04J 14/0282 WDM tree architectures
• CPC Class Codes: H04J 14/0283 WDM ring architectures
• CPC Class Codes: H04J 14/0286 WDM hierarchical architectures
• CPC Class Codes: H04J 14/0295 Shared protection at the optical channel (1:1, n:m)
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0039 Electrical control
• CPC Class Codes: H04Q 2011/0073 Provisions for forwarding or routing, e.g. lookup tables
• CPC Class Codes: H04Q 2011/0079 Operation or maintenance aspects

Abstract

An optical multi-drop path is set to a downstream direction, an optical path between adjacent nodes is set to a upstream direction, a packet sorting unit is provided for appropriately controlling packet streams in the downstream direction and upstream direction, and one-to-one or one-to-N communication can be performed not only between servers and clients but also between the clients even when a multi-drop transmission is used in the downstream direction.

Claims

1. A packet transfer device connected respectively to an optical node that performs branching and inserting an optical signal and a packet node that performs transmitting and receiving data of packet units, comprising:

a first interface that transmits and receives a packet between the optical nodes;

a second interface that transmits and receives the packet between the packet nodes; and

a transfer control unit that transfers the received packet to the first interface when receiving the packet from the second interface.

2. The device according to claim 1, wherein the transfer control unit discriminates whether a destination of the packet received from the first interface is a unicast address, and transfers the received packet to the first interface and the second interface if not the unicast address.

3. The device according to claim 2 further comprising an address storing unit, wherein the transfer control unit determines whether the unicast address is coincident with an packet node address stored in the address storing unit, when the destination of the received packet is the unicast address, transfers the received packet to the second interface if coincident, and transfers the received packet to the first interface if not coincident.

4. The device according to claim 2, wherein

the packet is a packet specified by Ethernet, and

the transfer control unit refers to an I/G bit contained in the destination to discriminate whether the received packet is the unicast address.

5. The device according to claim 3, wherein

the packet is a packet specified by Ethernet, and

the address is a MAC address.

6. The device according to claim 1, wherein

the transfer control unit transfers the received packet to the second interface when receiving the packet from the first interface.

7. The device according to claim 6 further comprising a third interface that transmits and receives the packet between optical nodes, wherein

the transfer control unit determines whether a destination of the packet is a unicast address when receiving the packet from the third interface, and transfers the received packet to the first interface if not the unicast address.

8. The device according to claim 7 further comprising an address storing unit that stores an address of the packet, wherein

the transfer control unit determines whether the unicast address is coincident with the packet node address stored in the address storing unit when the destination of the packet received from the third interface is the unicast address, transfers the received packet to the second interface if coincident, and transfers the received packet to the first interface if not coincident.