Distributed network repeater module and method

• US 6,431,765 B1
• Filed: 06/11/1999
• Issued: 08/13/2002
• Est. Priority Date: 06/11/1999
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Sinha, Santanu, Chen, John K., DeJager, Gregory Lee, Twiss, Robert Gregory, Parameswaran, Gopakumar, MacKay, Gordon, Hastings, Robert D., Nguyen, Van Van
• Primary Examiner(s): Healy, Brian
• Application Number:
  US09/330,733
• Time in Patent Office: 1,159 Days
• Field of Search: 385/14, 385/24, 385/15, 385/16, 385/88, 385/89, 385/92, 385/139, 359/124, 359/127, 359/154, 359/164, 359/166, 359/173
• US Class Current: 385/92
• CPC Class Codes: G02B 6/0001 specially adapted for lighting devices or systems lighting or signalling on vehicles using light guides B60Q1/00; lighting devices for vehicle dashboards B60Q3/10; lighting devices for vehicle interior using light guides B60Q3/62; lighting devices mounted on the vehicle rear part using light guides F21S43/235; measuring arrangements having light conducting pointers G01D13/265; illumination of liquid crystal displays G02F1/1336; illuminated signs G09F13/00
• CPC Class Codes: G02B 6/4277 Protection against electromagnetic interference [EMI], e.g. shielding means shielding of electric apparatus H05K9/00, of instruments G12B17/00
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers
• CPC Class Codes: H01R 13/6594 the shield being mounted on a PCB and connected to conductive members
• CPC Class Codes: H01R 13/6596 the conductive member being a metal grounding panel
• CPC Class Codes: H01R 2201/04 for network, e.g. LAN connectors
• CPC Class Codes: H01R 31/005 Intermediate parts for distributing signals

Abstract

A repeater, useable for connecting switches in a data communication network, is provided in a distributed and/or modular fashion. The repeater includes a plurality of separate and distinct components or modules connected to or at least partially housed in, the various switches which the repeater modules couple. The distributed and/or modular repeater facilitates accommodating various switching or repeater needs as a network grows or contracts. A light pipe, preferably integral with a module case, conveys indicator lights to a position visible when viewing a switch front panel. A heat spreader unit receives and/or conveys heat and/or protects against undue EMI. A collision-handling state machine transmits modified collision fragments so as to avoid reduction in interpacket gaps, e.g. by downstream repeater modules.

Claims

1. A network router device for coupling to a network switch comprising:

at least first and second distinct router modules;

at least said first router module having a casing and circuitry within said casing, with at least a first signal light positioned within said casing;

at least said first router module configured to be coupled in a first position with respect to said switch;

at least a first light pipe for conveying at least some light from said first signal light to a signal light output, wherein said signal light output is visible when said router module is in said first position.

2. A network router device as claimed in claim 1 wherein said switch has a front panel area and wherein said signal light output is visible when viewing said front panel area.

3. A network router device, as claimed in claim 1, wherein said light pipe is continuous with at least a portion of said casing.

4. A network router device, as claimed in claim 1, wherein said light pipe is integrally formed with at least a portion of said casing.

5. A network router device, as claimed in claim 1, wherein said casing is formed from at least a first injection-molded part and a second part and wherein said light pipe is formed with said first part in a single injection-molding operation.

6. A network router device, as claimed in claim 1, wherein at least one edge of said light pipe is spaced from adjacent portions of said casing to define an opening through said casing.

7. A network router device, as claimed in claim 1, wherein said light pipe includes a light entry region substantially adjacent said signal light.

8. A network router device, as claimed in claim 1, wherein said router device includes at least first and second ports, said signal light output being substantially adjacent said first port and further comprising a second light pipe defining a second signal light output substantially adjacent said second port.

9. A method for use with a network router device, said network router device for coupling to a network switch, the method comprising:

coupling at least a first router component in a first predefined position with respect to said switch;

controlling at least a first signal light, coupled to said first router component, to indicate at least first information relating to said router, wherein a signal light output is visible when said router component is in said first position.

10. A method, as claimed in claim 9 wherein said step of coupling a first router component comprises coupling one of a plurality of discrete modules of a modular router.

11. A method, as claimed in claim 10 wherein said first signal light is controlled to indicate whether said one module is coupled to at least a second of said plurality of modules.

12. A method, as claimed in claim 9 wherein said first signal light is controlled to indicate whether said router component is coupled to an approved cable.

13. A method, as claimed in claim 9 wherein said first signal light is controlled to indicate whether said router component is operating in full-duplex mode.

14. A method, as claimed in claim 9 wherein said first signal light is controlled to provide a signal including at least one of:

A constant-on light signal;

A constant-off light signal;

A light flash pattern; and

A light of any one of a plurality of colors.

15. A method as claimed in claim 9 further comprising conveying at least some light from said first signal light to said signal light output with a light pipe.

16. A method as claimed in claim 15 wherein said router component includes a casing and further comprising integrally forming said light pipe with at least a portion of said casing.

17. Apparatus for use with a network router device comprising:

a first router component configured for coupling in a first predefined position with respect to a network switch;

means for controlling at least a first signal light, coupled to said first router component, to indicate at least first information relating to said router,

means for locating a signal light output such that light from said signal light is visible when said router component is in said first position.

18. Apparatus, as claimed in claim 17, wherein said first router component includes a casing and wherein said means for locating comprises at least first light pipe means.

19. A network router device for coupling to a network switch comprising:

at least first and second distinct router modules;

at least said first router module having a casing and circuitry within said casing;

a heat spreader having a first region, having a first surface area positioned for thermal conduction with respect to at least a portion of said circuitry and a second region, said heat spreader configured to provide heat conduction between said first region and said second region.

20. A network router device, as claimed in claim 19, wherein said second region defines a surface area greater than said first surface area.

21. A network router device, as claimed in claim 19, wherein said portion of said circuitry comprises at least a first integrated circuit.

22. A network router device, as claimed in claim 19, further comprising at least one circuit board, having first and second opposite surfaces and first and second opposite edges, and wherein said portion of said circuitry is mounted on a mounting portion of said first surface of said circuit board.

23. A network router device, as claimed in claim 22, wherein said first region is adjacent a thermal contact portion of said second surface of said circuit board.

24. A network router device, as claimed in claim 23, wherein said thermal contact portion of said second surface is at least partially aligned with said mounting portion of said first surface.

25. A network router device, as claimed in claim 23, comprising a plurality of vias through said circuit board at least in said thermal contact portion.

26. A network router device, as claimed in claim 22, wherein at least some of said second region of said heat spreader is spaced from said second surface of said circuit board.

27. A network router device, as claimed in claim 19, wherein said heat spreader is comprises a substantially thermally conductive material.

28. A network router device, as claimed in claim 19, wherein said heat spreader is comprises a material which is both thermally conductive and electrically conductive.

29. A network router device, as claimed in claim 19, wherein said heat spreader is comprises copper.

30. A network router device, as claimed in claim 22, wherein said heat shield is substantially electrically conductive and includes at least first and second edges adjacent at least portions of said first and second edges of said circuit board, to cover at least a portion of said circuit board wherein electromagnetic interference (EMI) from said portion of said circuit board is reduced, compared to a configuration in which said portion of said circuit board is uncovered.

31. A network router device, as claimed in claim 30 further comprising a plurality of openings through at least said first and second edges of said heat shield.

32. A network router device, as claimed in claim 30, further comprising an electrically conductive pathway from said heat spreader to a chassis ground of said network switch.

33. A network router device, as claimed in claim 19, further comprising a plurality of vent holes through said casing wherein air flow through said vent holes provides heat dissipation from said heat spreader.

34. A network router device, as claimed in claim 23 including at least one thermally conductive seal, selected from among a thermally conductive wafer and a thermally conductive grease, located between said thermal contact region of said circuit board and said first region of said heat spreader.

35. A method for dissipating heat in a network router device, said device for coupling to a network switch, the method comprising:

coupling at least first and second distinct router modules to said network switch, at least said first router module having a casing and circuitry within said casing;

coupling a heat spreader having a first region, having a first surface area positioned for thermal conduction with respect to at least a portion of said circuitry and a second region, said heat spreader configured to provide heat conduction between said first region and said second region.

36. A method, as claimed in claim 35, wherein at least said first router module includes at least one circuit board, having first and second opposite surfaces and first and second opposite edges, wherein said portion of said circuitry is mounted on a mounting portion of said first surface of said circuit board, and wherein said heat shield is substantially electrically conductive and includes at least first and second edges, and further comprising:

positioning said first and second edges of said heat shield adjacent at least portions of said first and second edges of said circuit board, to cover at least a portion of said circuit board wherein electromagnetic interference (EMI) from said portion of said circuit board is reduced, compared to a configuration in which said portion of said circuit board is uncovered.

37. Apparatus for dissipating heat in a network router device, said device for coupling to a network switch, the apparatus comprising:

at least first and second distinct router modules configured for coupling to said network switch, at least said first router module having a casing and circuitry within said casing;

means for spreading heat, said means for spreading heat having a first region, positioned for thermal conduction with respect to at least a portion of said circuitry and a second region, said heat spreader configured to provide heat conduction between said first region and said second region.

38. Apparatus, as claimed in claim 37 wherein at least said first router module includes at least one circuit board, having first and second opposite surfaces and first and second opposite edges, wherein said portion of said circuitry is mounted on a mounting portion of said first surface of said circuit board, and wherein said heat shield is substantially electrically conductive and includes at least first and second edges, and further comprising:

means for positioning said first and second edges of said heat shield adjacent at least portions of said first and second edges of said circuit board, to cover at least a portion of said circuit board wherein electromagnetic interference (EMI) from said portion of said circuit board is reduced, compared to a configuration in which said portion of said circuit board is uncovered.

39. Apparatus, in a computer network, for avoiding reduction of interpacket gaps below a minimum gap value, comprising:

at least first and second distinct router modules configured for coupling to a network switch;

a state machine, in at least said first router module, configured to

receive a sequential plurality of communication packets;

recognize at least a first collision fragment, having a first form, in at least one of said communications packets; and

forward said at least one communications packet to said second router module, after altering said first collision fragment to a second form;

a state machine, in at least said second router module, configured to forward said at least one communications packet, received from said first router module with an altered collision fragment in said second form, in the absence of decreasing an interpacket gap.

40. Apparatus, as claimed in claim 39, wherein said state machine in said second module is substantially identical to said state machine in said first module.

41. Apparatus, as claimed in claim 39, wherein said state machine in said first module decreases an interpacket gap in response to receiving said one of said communications packets.

42. Apparatus, as claimed in claim 39 wherein said communications network communicates packets including V and R symbols in accordance with IEEE 802.3Z and wherein said first form includes a plurality of V symbols and wherein said second form has at least some of said V symbols replaced by R symbols.

43. A method, in a computer network, for avoiding reduction of interpacket gaps below a minimum gap value, comprising:

coupling at least first and second distinct router modules to a network switch;

receiving, in said first router module, a sequential plurality of communication packets;

recognizing, in said first router module, at least a first collision fragment, having a first form, in at least one of said communications packets;

forwarding, from said first router module to said second router module, said at least one communications packet, after altering said first collision fragment to a second form;

forwarding, from said second router module, said at least one communications packet, received from said first router module, in the absence of decreasing an interpacket gap below said minimum value.

44. Apparatus, in a computer network, for avoiding reduction of interpacket gaps below a minimum gap value, comprising:

at least first and second distinct router modules coupled to a network switch;

means, in said first router module, for;

receiving a sequential plurality of communication packets;

recognizing at least a first collision fragment, having a first form, in at least one of said communications packets; and

forwarding said at least one communications packet to said second router module, after altering said first collision fragment to a second form;

means, in said second router module, for forwarding, from said second router module, said at least one communications packet, received from said first router module, in the absence of decreasing an interpacket gap below said minimum value.