Dynamic Cable Assignment On Gigabit Infrastructure

• US 20070237166A1
• Filed: 06/14/2007
• Published: 10/11/2007
• Est. Priority Date: 12/17/2002
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Daryl Cromer, Howard Locker, Marc Pamley
• Inventors: Locker, Howard, Cromer, Daryl, Pamley, Marc
• Granted Patent: US 7,864,670 B2
• Time in Patent Office: Days
• US Class Current: 370/420
• CPC Class Codes: H04L 12/40182 by using a plurality of communication lines
• CPC Class Codes: H04L 12/5692 Selection among different networks

Abstract

A method and corresponding network interface device for communicating between devices connected to a LAN includes attempting to communicate between the network devices over an initial subset of the network media wires. If the communication fails, a subsequent subset of media wires is selected. The wires of this subsequent subset differ from the wires of the initial subset. If the attempted communication succeeds, the current subset of network media wires is used as the media over which subsequent network data is transmitted. Attempting to communicate over the media may include sending an initialization sequence such as an Ethernet Auto-negotiate sequence. In one embodiment, the network media is implemented as 8 wires of CAT 5 cabling suitable for use with a Gigabit Ethernet. In this embodiment, any subsequent subsets of the network media wires may consist of 4 of the 8 wires over which 100 Mbps Ethernet operation may occur.

Claims

1. A method of communicating between first and second devices connected by a network media comprising a set of wires, the method comprising:

attempting to communicate between the first and second network devices over a current subset of the network media wires;

responsive to determining that the attempted communication failed, selecting a subsequent subset of media wires wherein the network media wires within said subsequent subset and said current subset differ in at least one element; and

responsive to determining that the attempted communication succeeded, using at least the current subset of network media wires as the media over which subsequent network data is transmitted between the first and second devices.

2. The method of claim 1, wherein attempting to communicate over a network media comprises sending an initialization sequence responsive to connecting the first and second devices to the network media.

3. The method of claim 2, wherein sending an initialization sequence comprises initiating an Auto-negotiation sequence between the network devices.

4. The method of claim 1, wherein the network media comprises 8 wires of CAT 5 cabling and wherein the current and any subsequent subsets of the network media wires consists of 4 of the 8 wires.

5. The method of claim 1, wherein determining that the attempted communication failed comprises determining that a predetermined time period has elapsed.

6. The method of claim 1, wherein using the current subset of network media wires further comprises, responsive to successfully communicating between devices on a first attempt, using all of the network media wires as the media over which subsequent network data is transmitted.

7. The method of claim 6, further comprising, responsive to determining that transmission of network data over all of the media wires is unsuccessful, selecting the current subset of network media wires as the network medium.

8. A network interface device suitable for connecting a host device to a local area network (LAN), comprising:

a processor having access to random access memory (RAM) and read only storage (ROS) and configured to produce a set of processor signals;

a host interface unit (HIFU) including buffers and logic enabling communication with the host device;

a media interface unit (MIFU) configured to receive the set of processor signals and to produce a set of output signals based thereon that are provided to a LAN media; and

means for rerouting at least a portion of the processor signals, responsive to determining that communication over the media has failed, wherein the rerouting causes a subset of the MIFU output signals to be provided to a functional subset of media wires.

9. The network interface device of claim 8, further comprising means for sending an initialization sequence over at least a subset of the wires in the media.

10. The network interface device of claim 9, wherein the means for sending the initialization sequence comprises means for initiating an Auto-negotiation sequence between the network devices.

11. The network interface device of claim 8, wherein the network media comprises 8 wires of CAT 5 cabling and wherein the functional subset of wires consists of 4 of the 8 wires.

12. The network interface device of claim 8, wherein determining that the communication failed comprises determining that a predetermined time period has elapsed without successful completion of a communication.

13. The network interface device of claim 8, wherein responsive to successfully communicating over the media on a first attempt, the network interface is further configured to use all of the network media wires as the media over which subsequent network data is transmitted.

14. The network interface device of claim 13, wherein the network interface device is further characterized as a Gigabit Ethernet network interface device.

15. The network interface device of claim 14, wherein upon determining that the communication failed, the network interface device reroutes the processor signals to a subset of 4 wires and the network interface device operates as a 100 Mbps network interface device.

16. A network interface device suitable for connecting a data processing system to a local area network (LAN), comprising:

means for attempting to communicate with another device connected to the LAN over a current subset of the network media wires;

means for determining that the attempted communication failed and, responsive thereto, selecting a subsequent subset of media wires wherein the network media wires within said subsequent subset and said current subset differ in at least one element; and

means for determining that the attempted communication succeeded and, responsive thereto, using at least the current subset of network media wires as the media over which subsequent network data is transmitted between the first and second devices.

17. The network interface device of claim 16, wherein the means for attempting to communicate over a network media comprises means for sending an initialization sequence responsive to connecting the first and second devices to the network media.

18. The network interface device of claim 17, wherein the means for sending an initialization sequence comprises means for initiating an Auto-negotiation sequence between the network devices.

19. The network interface device of claim 16, wherein the network media comprises 8 wires and wherein the current and any subsequent subsets of the network media wires consists of 4 wires.

20. The network interface device of claim 16, wherein means for determining that the attempted communication failed comprises means for determining that a predetermined time period has elapsed.

21. The network interface device of claim 16, wherein the means for using the current subset of network media wires further comprises, responsive to successfully communicating between devices on a first attempt, means for using all of the network media wires as the media over which subsequent network data is transmitted.

22. The network interface device of claim 21, further comprising, means for selecting the current subset of network media wires as the network medium responsive to determining that transmission of network data over all of the media wires is unsuccessful.