Configurable Wan/Lan bridge

• US 6,108,345 A
• Filed: 05/30/1997
• Issued: 08/22/2000
• Est. Priority Date: 05/30/1997
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Zhang, Liping
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): Sam, Phirin
• Application Number:
  US08/865,739
• Time in Patent Office: 1,180 Days
• Field of Search: 370/445, 370/401, 370/402, 370/389, 370/408, 370/420, 370/451, 370/449, 370/447, 370/466, 370/444, 370/469, 370/455, 370/459, 370/461, 370/462, 370/250, 370/254, 370/282 , 370/285, 370/299, 370/303, 370/326, 370/327, 370/341, 370/345, 370/347, 370/359, 370/360, 370/362, 370/395, 370/396, 370/398, 370/400, 370/404, 370/419, 370/422 , 370/437, 370/438, 370/442, 340/825.08
• US Class Current: 370/445
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches

Abstract

A device for connecting networks includes at least two communication channels, a first and a second medium access controller, a bus, and a configurable switch. Each of the communication channels is configured to support a transfer of data packets. The first and second medium access controller is configured to transmit and receive data packets. A data packet received by one of the medium access controllers is transmitted by the other of the medium access controllers. The configurable switch connects the first and second medium access controllers to one of the communication channels and the second medium access controller to the other of the communication channels. The connections between the medium access controllers and the communicatoin channels can be reconfigured statically or dynamically by the configurable switch. The communication channels may operate on different physical protocols. A conversion unit is provided to convert a packet received by one medium access controller in a first protocol to a second physical protocol. A packet processor is provided to extract a destination header from a data packet, append a destination header, and pass the destination header and data packet to the second medium access controller.

The present invention can also be characterized as a method for statically and dynamically altering the connections of a medium access controller to one of at least two communication channels.

Claims

1. A remote access including:

at least two communication channels, including a first communication channel coupled a first network and a second communication channel coupled to a second network, and each of said at least two communication channels configured to support a transfer of a plurality of data packets;

a first port that couples the first communication channel to the first network using a first protocol;

a second port that couples the second communication channel to the second network using a second protocol;

a first medium access controller that is coupleable to the first port and the second port to transmit and receive at least a data packet in the plurality of data packets;

a second medium access controller that is coupleable to the first port and the second port to transmit and receive at least a data packet in the plurality of data packets;

a bus connecting said first and said second medium access controllers to pass at least some of the plurality of data packets received by one of said first and said second medium access controllers to an other of said first and said second medium access controllers;

a switch and conversion unit to selectively connect said first medium access controller to one of the first or second communication channel, and said second medium access controller to an other of the first or second communication channel,

wherein the switch and conversion unit is configurable to connect the first medium access controller to the first communication channel so that a data packet in the plurality of data packets with a destination identifier corresponding to said first medium access controller is received by said first medium access controller, and transmitted by said second medium access controller to the second communication channel, said switch and conversion unit being able to convert the data packet received by the first medium access controller from the first protocol of the first port to the second protocol of the second port by first converting the data packet to an intermediate protocol; and

a packet processor connected to said bus, said packet processor adapted to be forwarded said data packet received by said first medium access controller, and to pass said data packet to said second medium access controller after attaching a header to the said data packet, the header corresponding to a destination on the second network.

2. The remote access server of claim 1, wherein the first and second communication channel are further configured to support the transfer of the plurality of data packets in accordance with a carrier sense multiple access with collision detection (CSMA/CD) network protocol.

3. The remote access server of claim 1, wherein:

said first medium access controller further comprises a first identifier, and said first medium access controller configured to receive the data packet in the plurality of data packets which contains the destination identifier corresponding to said first identifier and to transmit a data packet in the plurality of data packets by appending a source identifier corresponding to said first identifier; and

said second medium access controller further comprises a second identifier, and said second medium access controller configured to receive a data packet in the plurality of data packets which contains a destination identifier corresponding to said second identifier and to transmit a data packet in the plurality of data packets by appending a source identifier corresponding to said second identifier.

4. The remote access server of claim 1, wherein said first physical protocol is a Manchester encoded protocol and said second physical protocol is a fast Ethernet protocol.

5. The remote access server of claim 1, wherein said first physical protocol is a slow Ethernet protocol and said second physical protocol is a slow Ethernet protocol.

6. The remote access server of claim 1, wherein said first physical protocol is a Manchester encoded protocol and said second physical protocol is a slow Ethernet protocol.

7. The remote access server of claim 1, wherein the packet processor extracts a destination header from said data packet, appends said destination header to said data packet, and passes said destination header and data packet to said second medium access controller.

8. The remote access server of claim 1, further comprising:

a third medium access controller to receive data packets containing switch configuration commands;

a controller coupled to said configurable switch and conversion unit and to said third medium access controller to pass said switch configuration commands to said configurable switch and conversion unit; and

said configurable switch and conversion unit further comprising a logic unit to reconfigure said switch in response to said switch configuration commands from said controller.

9. A method for connecting a medium access controller to one of at least two communication channels, each communication channel operating under a different protocol, said medium access controller equipped to transmit outgoing data packets with a source identifier corresponding to said medium access controller, and to receive incoming data packets which include a destination identifier corresponding to said medium access controller, and said method comprising:

detecting a switch request to connect the medium access controller to a selected one of said at least two communication channels;

then detecting that the medium access controller is available; and

connecting said medium access controller to said selected one of said at least two communication channels to receive or transmit a data packet in either the first or second protocol from the selected communication channel.

10. The method of claim 9, further comprising the step of;

implementing on each of said two communication channels a network protocol for a transfer of the incoming or outgoing data packets in accordance with a carrier sense multiple access with collision detection (CSMA/CD) network protocol.

11. The method of claim 9, further comprising the steps of;

detecting a next switch request to connect the medium access controller to an other selected one of said at least two communication channels;

receiving the incoming data packets the medium access controller in the first protocol; and

transmitting the outgoing data packets from the medium access controller in either the first or second protocol to said other selected one of said at least two communication channels.

12. The method of claim 11, wherein the detecting step further comprises the step of;

determining that the medium access controller is in a quiescent state by identifying a pause in data packet transfer.

13. The method of claim 11, wherein the detecting step further comprises the step of;

causing the medium access controller to abort the transfer of a data packet.

14. The method of claim 9, wherein receiving the switch request occurs upon receiving a run-time command with the incoming data packets to the medium access controller.

15. The method of claim 9, including a step of converting the incoming data packets from the first protocol to an intermediate protocol with the media access controller after receiving the incoming data packets, and from the intermediate protocol to the first or second protocol within the media access controller prior to transmitting the outgoing data packets.