Automatic communication protocol detection system and method for network systems

• US 6,072,803 A
• Filed: 04/20/1998
• Issued: 06/06/2000
• Est. Priority Date: 07/12/1995
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Compaq Computer Corporation (HP Inc.)
• Inventors: Nouri, Ahmad, Whitmire, Laura E., Allmond, David M., Bennett, Arthur T., Hoang, Hieu M., Hoang, Thao Minh
• Primary Examiner(s): Jung, Min
• Application Number:
  US09/062,892
• Time in Patent Office: 778 Days
• Field of Search: 370/465, 370/257, 370/410, 370/401, 370/402, 370/359, 370/445
• US Class Current: 370/445
• CPC Class Codes: H04L 12/44 Star or tree networks
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/6225 Fixed service order, e.g. Round Robin
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/9063 Intermediate storage in different physical parts of a node or terminal
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A communication protocol detection system for enabling a network system to detect and interface one or more network devices each operating according to at least one of a plurality of different communication protocols. In one embodiment, a network interface card (NIC) is capable of operating according to one of two different communication protocols, such as the 10Base-T and 100Base-TX Ethernet Standards. The NIC includes two corresponding transceivers, where the transceivers are interfaced to a network connector for interfacing an external network device. Control logic initially enables the 10Base-T transceiver to determine if link pulses are detected. If link pulses are detected, the 100Base-T transceiver is enabled to determine if it detects the link pulses. If so, the 100Base-T transceiver is used to establish communications, and if not, the 10Base-T transceiver is used. Preferably, the 100Base-T transceiver is re-enabled a predetermined number of times to determine if the network device is a 100 Mbps device. In another embodiment, a repeater includes a plurality of interface circuits, each including a plurality of transceivers. Each of the transceivers of each of the interface circuits of each port is connected to a corresponding repeater module through an array of buses. Control logic enables the transceivers one at a time within each interface circuit and correspondingly monitors the corresponding link signal. When an enabled transceiver detects link pulses, that transceiver is used to establish communications. If a link signal indicates termination of communications, enabling of the transceivers one at a time is resumed.

Claims

1. A network interface system for coupling to and interfacing with any network device that operates according to at least one of a plurality of communication protocols, the network interface system comprising:

a port for coupling to a network device, the network device operating according to at least one of a plurality of communication protocols and providing a corresponding one of a plurality of connection indications via the port;

a plurality of interface circuits coupled to the port, each corresponding to one of the plurality of communication protocols and each indicating detection of a compatible network device that is coupled to the port and providing a connection indication via the port; and

control logic, coupled to the plurality of interface circuits, that enables any one of the plurality of interface circuits indicating detection of a compatible network device to enable communication with the network device.

2. The network interface system of claim 1, further comprising:

the port including a plurality of signal connections; and

each of the plurality of connection indications comprising at least one signal asserted via at least one of the plurality of signal connections of the port.

3. The network interface system of claim 1, wherein each of the plurality of interface circuits comprises a transceiver that enables bidirectional communication via the port.

4. The network interface system of claim 1, further comprising:

a physical interface device that is coupled between the port and each of the plurality of interface circuits.

5. The network interface system of claim 1, further comprising:

a media access control device that is coupled to each of the plurality of interface circuits to enable to enable bidirectional communication via any one of the plurality of interface circuits that is enabled.

6. The network interface system of claim 5, further comprising:

a computer system that implements the control logic, comprising;

a memory that stores network software;

a processor coupled to the memory that executes the network software from the memory; and

an expansion bus that includes slots to receive expansion cards; and

a network expansion card, implemented for plugging into a slot of the expansion bus, that incorporates the media access control device, the port and the plurality of interface circuits, so that the media access control device and the plurality of interface circuits are coupled to the control logic via the expansion bus slot.

7. The network interface system of claim 1, wherein the control logic enables each of the plurality of interface circuits one at a time until one of the plurality of interface circuits indicates detection of a compatible network device.

8. The network interface system of claim 7, wherein the control logic keeps an interface circuit that indicates detection of a compatible network device enabled until it no longer indicates detection of a compatible network device, and then returns to enabling each of the plurality of interface circuits one at a time.

9. A communication protocol detection system for interfacing with at least one of a plurality of network devices, wherein each of the plurality of network devices operates according to at least one of a plurality of different communication protocols, the communication protocol detection system comprising:

a plurality of network ports;

a plurality of interface circuits, each corresponding to one of the plurality of network ports and each including a plurality of transceivers, wherein each of the plurality of transceivers of each of the plurality of interface circuits is coupled to the corresponding one of the plurality of network ports and corresponds to one of the plurality of communication protocols, and wherein each of the plurality of transceivers provides a detection indication upon detection of a compatible connection indication provided via the corresponding one of the plurality of network ports; and

control logic, coupled to each of the plurality of transceivers of each of the plurality of interface circuits, that enables any of the plurality of transceivers within each of the plurality of interface circuits that provides a detection indication.

10. The system of claim 9, wherein each of the plurality of transceivers of each of the plurality of interface circuits enables bidirectional communication via the corresponding one of the plurality of network ports according to one of the plurality of communication protocols.

11. The system of claim 9, wherein for each of the plurality of interface circuits, the control logic enables each of the plurality of transceivers one at a time until a transceiver provides a detection indication.

12. The system of claim 11, wherein the control logic keeps a transceiver that provides a detection indication within an interface circuit enabled until it no longer provides the detection indication, and then returns to enabling each of the plurality of transceivers one at a time within that interface circuit.

13. A method of detecting the communication protocol of a network device operating according to at least one of a plurality of communication protocols coupled to a network port of a network system, the network system including a plurality of transceivers coupled to the network port, wherein each of the plurality of transceivers corresponds to one of the plurality of communication protocols, and wherein each of the transceivers provides a detection indication upon detection of a compatible connection indication provided via the port, the method comprising the steps of:

for each transceiver, determining if a corresponding detection indication is provided; and

establishing communications via the port using a transceiver providing a detection indication.

14. The method of claim 13, further comprising the steps of:

periodically enabling each of the plurality of transceivers one at a time; and

for each enabled transceiver, determining if a corresponding detection indication is provided.

15. The method of claim 13, after the step of establishing communications, further comprising the steps of:

periodically monitoring the detection indication from the transceiver used for communications; and

when the detection indication from the transceiver is no longer provided, repeating the steps of determining if a corresponding detection indication is provided for each transceiver and establishing communications via the port using a transceiver providing a detection indication.