Method and apparatus for monitoring a dedicated communications medium in a switched data network

• US 6,047,321 A
• Filed: 09/27/1996
• Issued: 04/04/2000
• Est. Priority Date: 02/23/1996
• Status: Expired due to Term

• Current Assignee: Avaya Incorporated
• Original Assignee: Nortel Networks Corporation
• Inventors: Reddy, Sri, Stevens, David B., Smith, Robert W., Raab, Ilan
• Primary Examiner(s): Rinehart, Mark H.
• Application Number:
  US08/714,930
• Time in Patent Office: 1,285 Days
• Field of Search: 395/200.54, 395/183.15, 395/183.19, 395/200.69, 370/245, 370/247, 370/251, 370/253, 370/241, 370/452, 370/217, 702/58, 702/59, 702/122, 709/224, 709/229, 709/223, 709/239, 714/39, 714/41, 714/43
• US Class Current: 709/224
• CPC Class Codes: H04L 41/00 Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
• CPC Class Codes: H04L 43/12 Network monitoring probes

Abstract

A method and apparatus for monitoring the performance of a dedicated communications medium in a switched data networking environment wherein a probe having a bypass circuit allows promiscuous monitoring of all traffic between a switch and a network device, such as a file server, in either direction, and in full duplex mode. Additionally, the bypass circuit eliminates the requirement for a separate repeater between the switch and the network device.

Claims

1. A probe comprising:

a first port to communicatively couple with a first communications medium;

a second port to communicatively couple with a second communications medium;

a monitor to monitor communications passed from the first port to the second port; and

a bypass circuit to forward the communications from the first port to the second port, bypassing the monitor, when power to the probe is interrupted.

2. The probe of claim 1, wherein the monitor is to receive the communications from the first port when the probe is in a monitor mode.

3. The probe of claim 1, wherein the monitor is not to receive the communications from the first port when the probe is in a bypass mode.

4. The probe of claim 1 wherein the bypass circuit comprises:

a passive tap to communicatively couple with the first port and the second port; and

an amplifier to communicatively couple with the passive tap and the monitor, said amplifier to pass the communications from the first port to the monitor when power is applied to the amplifier.

5. A probe comprising:

a first port to communicatively couple with a first network device;

a second port to communicatively couple with a second network device;

a bypass circuit to couple the first port to the second port to forward communications received from the first network device via the first port to the second network device via the second port whether or not power is applied to the probe; and

a monitor to couple with the bypass circuit, the monitor to receive and monitor the communications forwarded from the first port to the second port when power is applied to the probe.

6. The probe of claim 5 wherein the bypass circuit is in a bypass mode when power is not applied to the probe, and the bypass circuit is in a monitor mode when power is applied to the probe.

7. The probe of claim 5 wherein the bypass circuit comprises:

a high impedance tap to couple with the first port and the second port; and

an amplifier having an input to couple with the high impedance tap and an output to couple with the monitor to receive the communications from the first port via the high impedance tap and forward the communications to the monitor.

8. A probe comprising:

a plurality of ports including a first port and a second port;

a monitoring device to monitor a transfer of data from the first port to the second port; and

a bypass circuit having at least two modes of operation, the bypass circuit to forward the data transferred from the first port to the second port and bypass the monitoring device when the bypass circuit is placed in a first mode of operation.

9. The probe of claim 8, wherein the bypass circuit includes a relay placed in an inactive state when the bypass circuit is placed in the first mode of operation, the relay in the inactive state to route the data from the first port to the second port and bypass the monitoring device.

10. The probe of claim 9, wherein the relay is in the inactive state when a supply of power to the probe is discontinued.

11. The probe of claim 9, wherein the bypass circuit further includes a repeater coupled to the relay and the monitoring device.

12. The probe of claim 11, wherein the relay of the bypass circuit routes the data from the first port to the monitoring device via the repeater when the relay is placed in an active state so that the bypass circuit is in a second mode of operation.

13. The probe of claim 8, wherein the bypass circuit includes

a line communicatively coupled to the first port to the second port, the line includes a passive tap;

an amplifier coupled between the passive tap and the monitoring device.

14. The probe of claim 13, wherein the line routes the data from the first port to the second port, bypassing the monitoring device when the amplifier is placed in an inactive state.

15. The probe of claim 14, wherein the amplifier is placed in the inactive state when a supply of power to the amplifier is discontinued.

16. The probe in claim 13, wherein the line routes the data from the first port to the monitoring device when the amplifier is placed in an active state, thereby placing the bypass circuit in a second mode of operation.

17. The probe of claim 8, wherein the data is in a packet format.

18. A network comprising:

a hub including a plurality of modules to handle data traffic from multiple network segments;

a switch including a plurality of ports, each port in communication with one of the plurality of modules;

a network device in communication with one of the plurality of ports; and

a probe coupled to the plurality of ports and the network device, the probe includes (i) a monitoring device and (ii) a bypass circuit to transfer data from a first port of the switch to the network device and to bypass the monitoring device when the probe is placed in a first mode of operation.

19. The network of claim 18, wherein the probe is placed in the first mode of operation by discontinuing a supply of power to the probe.

20. The network of claim 19, wherein the bypass circuit of the probe includes a relay to route the data from the first port of the switch to the network device and to bypass the monitoring device when a supply of power to the probe is discontinued.

21. The network of claim 18, wherein the bypass circuit further includes

a line communicatively coupling the first port and the second port, the line includes a passive tap;

and

an amplifier coupled between the passive tap and the monitoring device, the amplifier is placed in an inactive state when the bypass circuit is placed in the first mode of operation in order to bypass the monitoring device.

22. The network of claim 18, wherein the network device is a digital terminal equipment.

23. A method comprising:

receiving data by the probe disposed between a switch and at least one network device;

placing the probe is in a first mode of operation; and

bypassing a monitoring device of the probe by providing the data directly to the at least one network device when the probe is in the first mode of operation.

24. The method of claim 23, wherein prior to receiving data by the probe, the method further comprises coupling a relay between a first port of the probe coupled to the switch, a second port of the probe coupled to the network device and the monitoring device.

25. The method of claim 24, wherein the placing of the probe in the first mode of operation includes

placing the relay into an active state so that the first port is solely in communications with the second port.

26. The method of claim 25, wherein the placing of the relay in the inactive state includes discontinuing power to the probe.

27. The method of claim 23, wherein prior to receiving data by the probe, the method further comprises coupling an amplifier to a passive tap set along a transmit line coupling the first port and the second port.

28. The method of claim 27, wherein the placing of the probe in the first mode of operation includes placing the amplifier into an inactive state so that the first port is solely in communication with the second port.

29. A probe comprising:

first means for receiving data;

second means for receiving data;

monitor means for monitoring a transfer of data from the first means and the second means; and

means for forwarding the data transferred from the first means to the second means and for bypassing the monitor means when the means for forwarding is placed in a first of at least two modes of operation.