Automatic communication protocol detection system and method for network systems

• US 5,754,552 A
• Filed: 02/29/1996
• Issued: 05/19/1998
• 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: Whitmire, Laura E., Allmond, David M., Bennett, Arthur T., Hoang, Hieu M., Hoang, Thao Minh, Nouri, Ahmad
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Jung, Min
• Application Number:
  US08/608,819
• Time in Patent Office: 810 Days
• Field of Search: 370/254, 370/257, 370/465, 370/466, 370/445, 370/410, 370/401, 370/402
• US Class Current: 370/465
• 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 communication protocol detection system for a network system including at least one port for interfacing at least one network device operating according to at least one of a plurality of different communication protocols, the communication protocol detection system comprising:

a plurality of interface circuits for coupling to a port, each of said plurality of interface circuits corresponding to one of the plurality of different communication protocols for interfacing a compatible network device coupled to the port, for detecting link pulses from said compatible network device coupled to the port and for providing a corresponding one of a plurality of link detect signals indicative thereof, and

control logic coupled to enable each one of said plurality of interface circuits and coupled to receive each of said plurality of link detect signals, wherein said control logic enables an appropriate one of said plurality of interface circuits based on detection of a corresponding one of said plurality of link detect signals.

2. The communication protocol detection system of claim 1, wherein each of said plurality of interface circuits comprises a transceiver for enabling bidirectional communication.

3. The communication protocol detection system of claim 2, wherein said plurality of interface circuits comprises:

a first transceiver for coupling to the port for enabling operation at 10 megabits per second (Mbps); and

a second transceiver for coupling to the port for enabling operation at 100 Mbps.

4. The communication protocol detection system of claim 3, wherein said control logic initially enables said first transceiver and disables said second transceiver, and in response to receiving a corresponding link detect signal being provided from said first transceiver, said control logic enables said second transceiver and disables said first transceiver to determine if a corresponding link detect signal is provided from said second transceiver, wherein if said control logic determines that a link signal is provided from said second transceiver said control logic keeps said second transceiver enabled and if a link signal is not provided from said second transceiver, said control logic re-enables said first transceiver.

5. The communication protocol detection system of claim 4, wherein said control logic re-enables said second transceiver a predetermined number of times while monitoring said link detect signal corresponding to said second transceiver to determine if a network device is coupled to the port and operating at 100 Mbps.

6. The communication protocol detection system of claim 4, wherein said control logic enables said second transceiver while monitoring said link detect signal corresponding to said second transceiver for a predetermined time period to determine if a network device coupled to the port is operating at 100 Mbps.

7. The communication protocol detection system of claim 3, wherein said control logic toggles between enabling said first and second transceivers until a corresponding link detect signal is provided.

8. The communication protocol detection system of claim 7, wherein said control logic re-enables said second transceiver a predetermined number of times while monitoring said link detect signal corresponding to said second transceiver to determine if a network device is coupled to the port and operating at 100 Mbps.

9. The communication protocol detection system of claim 1, wherein said control logic comprises control circuitry for receiving each of said plurality of link detect signals and for enabling each of said plurality of interface circuits one at a time.

10. The communication protocol detection system of claim 9, further comprising;

a media access device coupled to said plurality of interface circuits; and

wherein said control circuitry includes a processor for executing a software routing for controlling said media access device.

11. The communication protocol detection system of claim 10, further comprising:

a computer system incorporating said processor for executing said software routine, said computer system further including an input/output (I/O) bus for receiving I/O cards and interface circuitry for interfacing said processor to said I/O bus; and

a network interface card including said media access device and said plurality of interface circuits, wherein said network interface card is implemented for plugging into an I/O slot of said computer system.

12. A communication protocol detection system for a network system for interfacing 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 connectors;

a plurality of interface circuits, each corresponding to one of said plurality of network connectors and each including a plurality of transceivers coupled to a corresponding one of said plurality of network connectors, wherein each of said plurality of transceivers of each of said plurality of interface circuits corresponds to one of said plurality of communication protocols, and wherein each of said plurality of transceivers is separately enabled for detecting link pulse signals indicative of connection of a compatible network device coupled to said corresponding one of said plurality of network connectors and for providing a corresponding link detect signal indicative thereof; and

control logic coupled to said plurality of interface circuits for receiving and monitoring a plurality of link detect signals, each of said plurality of link detect signals corresponding to one of said plurality of transceivers, wherein said control logic enables one of said plurality of transceivers within each of said plurality of interface circuits.

13. The communication protocol detection system of claim 12, wherein said plurality of transceivers within each of said plurality of interface circuits further includes at least one 10Base-T transceiver and at least one 100Base-T transceiver.

14. The communication protocol detection system of claim 12, wherein said control logic includes a processor.

15. The communication protocol detection system of claim 14, further comprising:

select logic for receiving and monitoring said plurality of link detect signals and for interrupting said processor in the event any one of said plurality of link detect signals indicates a change of a corresponding one of said plurality of interface circuits.

16. The communication protocol detection system of claim 14, further comprising:

select logic for receiving said plurality of link detect signals and select signals from said processor for providing a selected one of said plurality of link detect signals requested by said processor as indicated by said select signals.

17. The communication protocol detection system of claim 14, further comprising:

each of said plurality of interface circuits including enable logic for enabling one of said plurality of transceivers; and

wherein said processor provides select signals to select the enable logic of one of said plurality of interface circuits and asserts enable data to said selected enable logic to select one of said plurality of transceivers within said one of said plurality of interface circuits.

18. The communication protocol detection system of claim 12, further comprising:

a plurality of communication devices, each corresponding to one of the plurality of communication protocols; and

a bus array for coupling each of said plurality of communication devices to a corresponding one of said plurality of transceivers within each of said plurality of interface circuits.

19. The communication protocol detection system of claim 18, wherein each of said plurality of communication devices comprises a network repeater.

20. The communication protocol detection system of claim 12, wherein said control logic initially enables one of said plurality of transceivers within each of said plurality of interface circuits, and upon indication by one of said plurality of link detect signals, enables each of said plurality of transceivers one at a time within an interface circuit corresponding to said one of said plurality of link detect signals while monitoring said one of said plurality of link detect signals.

21. The communication protocol detection system of claim 12, wherein said control logic enables each of said plurality of transceivers one at a time within each of said plurality of interface circuits while monitoring said plurality of link detect signals.

22. The communication protocol detection system of claim 21, wherein when any one of said plurality of link detect signals indicates connection to a network device, said control logic maintains enablement of a currently enabled transceiver within an interface device corresponding to said one of said plurality of link detect signals.

23. The communication protocol detection system of claim 22, wherein said control logic continues to monitor said one of said plurality of link detect signals until it indicates that said connection to a network device is disconnected, wherein said control logic resumes enabling each of said plurality of transceivers one at a time within said corresponding interface circuit while monitoring said plurality of link detect signals.

24. A method of detecting the communications protocol of a network device operating according to at least one of a plurality of communication protocols coupled to a network connector of a network system, the network device sending signals through the network connector to the network system when connected thereto, the network system including first and second interface devices corresponding to first and second communication protocols, respectively, wherein the first and second interface devices are separately enabled, and wherein the first and second interface devices each provide a link detect signal indicating detection by an interface device of the network device being present and transmitting link pulse signals, comprising the steps of:

enabling the first interface device;

periodically monitoring a link detect signal from the first interface device for an indication that a network device is detected by the first interface device;

if the first interface device detects a network device, disabling the first interface device and enabling the second interface device;

periodically monitoring a link detect signal from the second interface device for an indication that the network device is detected by the second interface device;

if the second interface device detects the network device while being enabled, establishing communications using the second interface device; and

if the second interface device does not detect the network device while being enabled, disabling the second interface device, re-enabling the first interface device and establishing communications using the first interface device.

25. The method of claim 24, further comprising the steps of:

after either of said steps of establishing communications using the first and the second interface device, periodically monitoring the corresponding link detect signal of the enabled interface device for an indication that the network device is still present.

26. The method of claim 24, further comprising the step of:

repeating said steps of disabling the first interface device, enabling the second interface device, re-enabling the first interface device and periodically monitoring the corresponding link detect signals for up to a predetermined number of times while the network device is detected by the first interface device but not detected by the second interface device.

27. The method of claim 26, further comprising the steps of:

if the network device is detected by the second interface device, establishing communications using the second interface device; and

if the network device is not detected by the second interface device, establishing communications using the first interface device.

28. The method of claim 24, wherein said step of monitoring the link detect signal corresponding to the second interface device for an indication that the network device is detected by the second interface device is performed for a predetermined period of time before said step of disabling the second interface device.

29. The method of claim 24, wherein the first and second communication protocols are, and the first and second interface devices operate according to, the 10Base-T and 100Base- T Ethernet standards, respectively.

30. 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 connector of a network system, the network device sending signals through the network connector to the network system when connected thereto, the network system including an interface device including a plurality of transceivers coupled to the network connector, wherein the plurality of transceivers correspond to the plurality of communication protocols and are separately enabled, and wherein each of the transceivers provides a link detect signal indicating that an enabled transceiver has detected a network device coupled to the corresponding network connector and is transmitting link pulse signals, the method comprising the steps of:

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

for each enabled transceiver, monitoring a corresponding link detect signal for an indication that a network device is detected by the enabled transceiver; and

if the link detect signal indicates that an enabled transceiver detects a network device, establishing communications with that network device and the using the currently enabled transceiver.

31. The method of claim 30, wherein the network system includes a plurality of network connectors for interfacing a plurality of network devices, each operating according to one of the plurality of communication protocols, the network system including a plurality of interface devices each corresponding to one of the plurality of network connectors and each including a plurality of transceivers coupled to a corresponding network connector and asserting a corresponding one of a plurality of link detect signals, further comprising the steps of:

periodically enabling each of the plurality of transceivers one at a time within each of the plurality of interface devices;

periodically monitoring each of the plurality of link detect signals for an indication that a network device is detected by an enabled transceiver; and

if a link detect signal indicates that an enabled transceiver detects a network device, establishing communications with that network device using the currently enabled transceiver.

32. The method of claim 30, after said step of establishing communications with a network device, further comprising the steps of:

continuously monitoring the link detect signal from the enabled transceiver to determine whether communications are terminated; and

if the link detect signal from the enabled transceiver indicates communications are terminated, repeating said steps of monitoring each of the plurality of link detect signals for an indication that a network device is detected by an enabled transceiver and establishing communications with that network device if a link detect signal corresponding to the enabled transceiver indicates that an enabled transceiver detects another network device.