Network interconnection system

• US 20010040890A1
• Filed: 03/02/2001
• Published: 11/15/2001
• Est. Priority Date: 03/02/2000
• Status: Active Grant

• Current Assignee: Rakuten Group, Inc.
• Original Assignee: NEC Corporation
• Inventors: Yamashita, Atsuya
• Granted Patent: US 6,975,646 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]

Abstract

A network interconnection system allowing simplified processing of signal conversion is disclosed. The network interconnection system has a plurality of input and output ports that are connected to different networks. An input interface connected to each of the input ports converts the input signal to an LCH packet signal when an input signal is not a MAC frame. A form of the LCH packet signal is identical to the MAC frame and a content of the LCH packet signal corresponding to a source address field of the MAC frame is set to all 0, which is inhibited in the MAC frame format. An output interface connected to each of the output ports converts the LCH packet signal to a signal conforming to a corresponding network when receiving an LCH packet signal as an output signal. A switch forwards an LCH packet signal received from one of input interfaces to an appropriate one of output interfaces based on a destination of an original signal of the received LCH packet signal.

Claims

1. A network interconnection system comprising:

a plurality of input and output ports that are connected to different networks;

an input interface connected to each of the input ports, wherein, when an input signal is not a signal of a predetermined signal format, the input interface converts the input signal to an interim packet signal, wherein a form of the interim packet signal is identical to the predetermined signal format and a content of a predetermined portion of the interim packet signal is different from a counterpart of any packet signal of the predetermined signal format;

an output interface connected to each of the output ports, wherein, when receiving an interim packet signal as an output signal, the output interface converts the interim packet signal to a signal conforming to a corresponding network; and

a switch for forwarding an interim packet signal received from one of input interfaces to an appropriate one of output interfaces based on a destination of an original signal of the received interim packet signal.

2. The network interconnection system according to

claim 1

, wherein a signal of the predetermined signal format is widely used in a computer network.

3. The network interconnection system according to

claim 2

, wherein a signal of the predetermined signal format is an Ethernet packet signal.

4. The network interconnection system according to

claim 3

, wherein the predetermined portion of the interim packet signal corresponding to a source address of the Ethernet packet signal is set to a unique bit string that is not used in Ethernet packet format.

5. The network interconnection system according to

claim 4

, wherein the predetermined portion of the interim packet signal corresponding to a source address of the Ethernet packet signal is set to all 0s.

6. The network interconnection system according to

claim 3

, wherein the predetermined portion of the interim packet signal corresponding to a source address of the Ethernet packet signal is set to a unique bit string in a world-wide computer network.

7. A network interconnection system comprising:

a plurality of input/output ports that are connected to outside networks, respectively;

a network interface port connected to each of the input/output ports;

a packet converter connected to the network interface port; and

a hub connecting packet converters corresponding to respective ones of the input/output ports, wherein

the network interface port comprises;

a packet memory for storing an input packet signal received from a corresponding input/output port; and

a first determiner for determining whether the input packet signal is an MAC (media access control) frame signal, to output a determination result and the input packet signal to the packet converter, and

the packet converter comprises;

a LCH header generator for generating a local channel header when it is determined that the input packet signal is not the MAC frame signal;

a LCH packet combiner for combining the local channel header and the input packet signal to produce a local channel packet signal to be sent to the hub, wherein a form of the local channel packet signal is identical to the MAC frame signal and a content of a predetermined portion of the local channel packet signal is different from a counterpart of any MAC frame signal;

a second determiner for determining whether an output packet signal is a local channel packet signal; and

a local packet checker for reproducing a packet signal conforming to a corresponding network from the output packet signal when the output packet signal is a local channel packet signal, wherein, when the output packet signal is an MAC frame signal, the output packet signal is output as it is to the corresponding network.

8. The network interconnection system according to

claim 7

, wherein the predetermined portion of the local channel packet signal corresponding to a source address of the MAC frame signal is set to a unique bit string that is not used in the MAC frame signal.

9. The network interconnection system according to

claim 8

, wherein the predetermined portion of the local channel packet signal corresponding to a source address of the MAC frame signal is set to all 0s.

10. The network interconnection system according to

claim 7

, wherein the predetermined portion of the local channel packet signal corresponding to a source address of the MAC frame signal is set to a unique bit string in a world-wide computer network.

11. A method for connecting a plurality of networks to each other through a switch having a plurality of input and output ports, comprising the steps of:

storing an input packet signal received from an input port corresponding to a network;

determining whether the input packet signal is an MAC (media access control) frame signal;

when it is determined that the input packet signal is not an MAC frame signal, generating a local channel header based on a destination of the input packet signal;

combining the local channel header and the input packet signal to produce a local channel packet signal, wherein a form of the local channel packet signal is identical to the MAC frame signal and a content of a predetermined portion of the local channel packet signal is different from a counterpart of any MAC frame signal;

forwarding the local channel packet signal to a destination output port; and

when it is determined that the input packet signal is an MAC frame signal, forwarding the input packet signal as it is to a destination output port.

12. The method according to

claim 11

, further comprising the steps of:

determining whether an output packet signal is a local channel packet signal;

when the output packet signal is a local channel packet signal, reproducing a packet signal conforming to a corresponding network from the output packet signal; and

when the output packet signal is an MAC frame signal, outputting the output packet signal as it is to the corresponding network.

13. The method according to

claim 11

, wherein the predetermined portion of the local channel packet signal corresponding to a source address of the MAC frame signal is set to a unique bit string that is not used in MAC frame format.

14. The method according to

claim 13

, wherein the predetermined portion of the local channel packet signal corresponding to a source address of the MAC frame signal is set to all 0s.

15. The method according to

claim 13

, wherein the predetermined portion of the local channel packet signal corresponding to a source address of the MAC frame signal is set to a unique bit string in a world-wide computer network.