Atomic network switch with integrated circuit switch nodes

• US 5,802,054 A
• Filed: 08/16/1996
• Issued: 09/01/1998
• Est. Priority Date: 08/15/1996
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Bellenger, Donald M.
• Primary Examiner(s): Patel, Ajit
• Application Number:
  US08/698,745
• Time in Patent Office: 746 Days
• Field of Search: 370/351, 370/400, 370/401, 370/402, 370/407, 370/408, 370/422
• US Class Current: 370/401
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 49/25 Routing or path finding in a switch fabric
• CPC Class Codes: H04L 49/3009 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/602 Multilayer or multiprotocol switching, e.g. IP switching

Abstract

An atomic type switch mesh is combined with standard local area network links, such as high speed Ethernet, and a bridge-like protocol to provide a high performance scalable network switch. The network switch comprises a plurality of switch nodes, a first set of communication links which are coupled between switch nodes internal to the network switch, and a second set of communication links which comprise network links from switch nodes on the border of the network switch to systems external to the network switch. The respective switch nodes include a set of ports (having more than two members) which are connected to respective communication links in either the first or second set of communication links. Each port in the set comprises a medium access control (MAC) logic unit for a connectionless network protocol, preferably high speed Ethernet. The switch nodes also include a route table memory which has a set of accessible memory locations that store switch route data specifying routes through the plurality of switch nodes within the boundaries of the network switch. Flow detect logic is coupled with the set of ports on the switch node, which monitors frames received by the set of ports and generates an identifying tag for use in accessing the route table memory. Finally, the switch node includes node route logic which is coupled with the flow detect logic, the route table memory and the set of ports. The node route logic monitors frames received by the set of ports to route a received frame for transmission out a port in the set of ports.

Claims

1. For a network switch including a mesh of interconnected network switch nodes, a network switch node comprising:

a set of ports having more than two members, and the ports in the set including respective medium access control units for transmission and reception of data frames according to a network protocol, the ports in the set of ports being connectable to a port on another network switch node inside the mesh, or to a network communication medium outside the mesh; and

node route logic, coupled with the set of ports, which monitors frames received by the set of ports to route a received frame for transmission according to the network protocol to a selected port in the set of ports, including logic to select the selected port according to rules for navigating through the mesh inside to the network switch, and wherein the node route logic forwards the received frame for transmission to a default location of a multiprotocol router resource associated with the switch when the node route logic cannot otherwise determine a route for the received frame.

2. The network switch node of claim 1, wherein the network protocol comprises a connectionless protocol.

3. The network switch node of claim 1, wherein the network protocol comprises an Ethernet protocol.

4. The network switch node of claim 1, wherein the network protocol comprises an Ethernet, full duplex protocol.

5. The network switch node of claim 1, wherein ports in the set of ports include medium independent interfaces for the network protocol.

6. The network switch node of claim 1, further including:

route table memory, coupled with the node route logic, having a set of accessible locations for storing switch route data;

flow detect logic, coupled with the set of ports, which monitors frames received by the set of ports and generates an identifying tag for use in accessing the route table memory;

wherein the node route logic includes logic which determines whether the received frame includes a switch route field indicating a port in the set of ports, and if the received frame includes a switch route field, updates the switch route field, and forwards the received frame with the updated switch route field to the port indicated by the switch route field, and if the received frame does not include a switch route field, accesses the route table memory using the identifying tag generated in the flow detect logic to retrieve switch route data indicating a port in the set of ports, adds a switch route field to the received frame, and forwards the received frame with the switch route field to the port indicated by the switch route data.

7. The network switch node of claim 6, wherein the default location includes a default port and wherein the node route logic forwards the received frame for transmission on the default port in the set of ports when the switch route table does not include switch route data for the identifying tag.

8. The network switch node of claim 7, wherein the default port is coupled to a route to a multi-protocol, network route processor at which switch route data is generated.

9. The network switch node of claim 6, including logic to receive switch route data from a remote system for a particular identifying tag, to store the switch route data in the route table memory in association with the particular identifying tag, and to block frames having the particular identifying tag until notification is received that it is clear to forward frames having the particular identifying tag, and after notification is received that it is clear to forward frames having the particular identifying tag, forward frames having the particular tag according to the switch route data.

10. The network switch node of claim 6, wherein the default location includes a default port and wherein the node route logic forwards the received frame for transmission on the default port in the set of ports when the route table memory does not include switch route data for the identifying tag;

and further including;

logic to receive switch route data from a remote system for a particular identifying tag, to store the switch route data in the route table memory in association with the particular identifying tag, and to block frames having the particular identifying tag until notification is received that it is clear to forward frames having the particular identifying tag, and after notification is received that it is clear to forward frames having the particular identifying tag, forward frames having the particular tag according to the switch route data.

11. The network switch node of claim 10, wherein the default port is coupled to a route to a multi-protocol, network route processor at which switch route data is generated.

12. The network switch node of claim 6, wherein the flow detect logic comprises:

logic which computes a plurality of hash values in response to respective sets of control fields in a received frame, where the respective sets of control fields correlate with respective network frame formats; and

logic which determines a particular network frame format for a received frame, and selects one of the plurality of hash values as the identifying tag in response to the particular network frame format.

13. The network switch node of claim 12, wherein the hash values comprise pseudo-random codes.

14. The network switch node of claim 6, wherein the flow detect logic comprises:

logic which computes a hash value in response to a set of control fields in a received frame, where the set of control fields correlates with a network frame format, and applies the hash value as the identifying tag.

15. The network switch node of claim 14, wherein the hash value comprises a pseudo-random code.

16. The network switch node of claim 1, wherein the network protocol comprises an Ethernet protocol, specified for operation at 100 Megabits per second.

17. The network switch node of claim 16, wherein the Ethernet protocol comprises a full duplex protocol.

18. The network switch node of claim 1, wherein said set of ports and said node route logic comprise elements of a single integrated circuit.

19. The network switch node of claim 18, wherein ports in the set of ports include medium independent interfaces for the network protocol, and the network protocol comprises an Ethernet protocol, specified for operation at 100 Megabits per second or higher.

20. The network switch node of claim 19, wherein the Ethernet protocol comprises a full duplex protocol.

21. The network switch node of claim 1, wherein ports of the set of ports include medium independent interfaces for the network protocol, the medium independent interfaces defining a particular bus configuration, and further including connectors coupled to the medium independent interfaces adapted to receive cables configured according to the particular bus configuration.

22. An integrated circuit, comprising:

a set of ports for access to respective communication media, the set of ports having more than two members, and the ports in the set including respective medium access control logic for a network protocol;

a memory interface for connection to a route table memory having a set of accessible locations for storing switch route data;

flow detect logic, coupled with the set of ports, which monitors frames received by the set of ports and generates an identifying tag for use in accessing the route table memory; and

node route logic, coupled with the flow detect logic, the memory interface and the set of ports, which monitors frames received by the set of ports to route a received frame for transmission to a port in the set of ports, the node route logic determining whether the received frame includes a switch route field indicating a port in the set of ports, and if the received frame includes a switch route field, updates the switch route field, and forwards the received frame with the updated switch route field to the port indicated by the switch route field, and if the received frame does not include a switch route field, accesses the route table memory through the memory interface using the identifying tag generated in the flow detect logic to retrieve switch route data indicating a port in the set of ports, adds a switch route field to the received frame, and forwards the received frame with the switch route field to the port indicated by the switch route data and if the route table memory does not include switch route data for the identifying tag, then forwards the received frame to a default location of a multiprotocol router resource associated with the switch.

23. The integrated circuit of claim 22, wherein the network protocol comprises a connectionless protocol.

24. The integrated circuit of claim 22, wherein the network protocol comprises an Ethernet protocol.

25. The integrated circuit of claim 24, wherein the Ethernet protocol comprises a full duplex protocol.

26. The integrated circuit of claim 22, wherein ports in the set of ports include medium independent interfaces for the network protocol.

27. The integrated circuit of claim 22, wherein the default location includes a default port and wherein the node route logic forwards the received frame for transmission on the default port in the set of ports when the switch route table does not include switch route data for the identifying tag.

28. The integrated circuit of claim 27, including logic to receive switch route data from a remote system for a particular identifying tag, to store the switch route data in the route table memory in association with the particular identifying tag, and to block frames having the particular identifying tag until notification is received that it is clear to forward frames having the particular identifying tag, and after notification is received that it is clear to forward frames having the particular identifying tag, forward frames having the particular identifying tag according to the switch route data.

29. The integrated circuit of claim 22, wherein the default location includes a default port and wherein the node route logic forwards the received frame for transmission on the default port in the set of ports when the route table memory does not include switch route data for the identifying tag;

and further including;

logic to receive switch route data from a remote system for a particular identifying tag, to store the switch route data in the route table memory in association with the particular identifying tag, and to block frames having the particular identifying tag until notification is received that it is clear to forward frames having the particular identifying tag, and after notification is received that it is clear to forward frames having the particular identifying tag, forward frames having the particular identifying tag according to the switch route data.

30. The integrated circuit of claim 22, wherein the flow detect logic comprises:

logic which computes a plurality of hash values in response to respective sets of control fields in a received frame, where the respective sets of control fields correlate with respective network frame formats; and

logic which determines a particular network frame format for a received frame, and selects one of the plurality of hash values as the identifying tag in response to the particular network frame format.

31. The integrated circuit of claim 30, wherein the hash values comprise pseudo-random codes.

32. The integrated circuit of claim 22, wherein the flow detect logic comprises:

logic which computes a hash value in response to set of control fields in a received frame, where the set of control fields correlates with a network frame format, and applies the hash value as the identifying tag.

33. The integrated circuit of claim 32, wherein the hash value comprises a pseudo-random code.

34. The integrated circuit of claim 22, including an embedded bus interconnecting the set of ports, the flow detect logic, the node route logic and the memory interface.

35. The integrated circuit of claim 22, wherein the network protocol comprises an Ethernet protocol, specified for operation at 100 Megabits per second or higher.

36. The integrated circuit of claim 35, wherein the Ethernet protocol comprises a full duplex protocol.

37. The integrated circuit of claim 35, including a bi-directional, embedded bus interconnecting the set of ports, the flow detect logic, the node route logic and the memory interface, the embedded bus specified for operation at 1 Gigabit per second or higher.

38. The integrated circuit of claim 22, including the route table memory on the integrated circuit.

39. A network switch, comprising:

a plurality of switch nodes;

a first set of communication links, communication links in the first set coupled between switch nodes in the plurality of switch nodes internal to the network switch;

a second set of communication links, communication links in the second set comprising network links external to the network switch;

the respective switch nodes in the plurality of switch nodes including

a set of ports connected to respective communication links in either the first set of communication links or the second set of communication links, the set of ports having more than two members, and the ports in the set including respective medium access control logic for a network protocol;

route table memory having a set of accessible locations for storing switch route data which specify routes through the plurality of switch nodes;

flow detect logic, coupled with the set of ports, which monitors frames received by the set of ports and generates an identifying tag for use in accessing the route table memory; and

node route logic, coupled with the flow detect logic, the route table memory and the set of ports, which monitors frames received by the set of ports to route a received frame for transmission to a port in the set of ports, the node route logic determining whether the received frame includes a switch route field indicating a port in the set of ports, and if the received frame includes a switch route field, updates the switch route field, and forwards the received frame with the updated switch route field to the port indicated by the switch route field, and if the received frame does not include a switch route field, accesses the route table memory using the identifying tag generated in the flow detect logic to retrieve switch route data indicating a port in the set of ports, adds a switch route field to the received frame, and forwards the received frame with the switch route field to the port indicated by the switch route data, and if the route table memory does not include switch route data corresponding to the identifying tag, then forwarding the received frame to a default location of a multiprotocol router resource associated with the switch.

40. The network switch of claim 39, wherein the network protocol for ports in the set of ports on the respective switch nodes comprises a connectionless protocol.

41. The network switch of claim 39, wherein the network protocol for ports in the set of ports on the respective switch nodes comprises an Ethernet protocol.

42. The network switch of claim 41, wherein the Ethernet protocol comprises a full duplex protocol.

43. The network switch of claim 39, wherein ports in the set of ports on the respective switch nodes include medium independent interfaces for the network protocol.

44. The network switch of claim 39, wherein the default location includes a default port and wherein the node route logic on the respective switch nodes forwards the received frame for transmission on the default port in the set of ports when the switch route table does not include switch route data for the identifying tag.

45. The network switch of claim 44, wherein the default port is coupled to a route to a multi-protocol, network route processor at which switch route data is generated.

46. The network switch of claim 39, including logic on the respective switch nodes to receive switch route data from a remote system for a particular identifying tag, to store the switch route data in the route table memory in association with the particular identifying tag, and to block frames having the particular identifying tag until notification is received that it is clear to forward frames having the particular identifying tag, and after notification is received that it is clear to forward frames having the particular identifying tag, forward frames having the particular identifying tag according to the switch route data.

47. The network switch of claim 39, wherein the node route logic on the respective switch nodes forwards the received frame for transmission on a default port in the set of ports when the route table memory does not include switch route data for the identifying tag;

and further including;

logic on the respective switch nodes to receive switch route data from a remote system for a particular identifying tag, to store the switch route data in the route table memory in association with the particular identifying tag, and to block frames having the particular identifying tag until notification is received that it is clear to forward frames having the particular identifying tag, and after notification is received that it is clear to forward frames having the particular identifying tag, forward frames having the particular identifying tag according to the switch route data.

48. The network switch of claim 47, wherein the default port is coupled to a route to a multi-protocol, network route processor at which switch route data is generated.

49. The network switch of claim 39, wherein the flow detect logic on the respective switch nodes comprises:

logic which computes a plurality of hash values in response to respective sets of control fields in a received frame, where the respective sets of control fields correlate with respective network frame formats; and

logic which determines a particular network frame format for a received frame, and selects one of the plurality of hash values as the identifying tag in response to the particular network frame format.

50. The network switch of claim 49, wherein the hash values comprise pseudo-random codes.

51. The network switch of claim 39, wherein the flow detect logic on the respective switch nodes comprises:

logic which computes a hash value in response to set of control fields in a received frame, where the set of control fields correlates with a network frame format, and applies the hash value as the identifying tag.

52. The network switch of claim 51, wherein the hash value comprises a pseudo-random code.

53. The network switch of claim 39, wherein the network protocol for ports in the set of ports on the respective switch nodes comprises an Ethernet protocol, specified for operation at 100 Megabits per second or higher.

54. The network switch of claim 53, wherein the Ethernet protocol comprises a full duplex protocol.

55. The network switch of claim 39, wherein the MAC logic for ports in the set of ports on the respective switch nodes executes the same network protocol for all ports in the set of ports.

56. The network switch of claim 39, wherein ports in the set of ports on the respective switch nodes include medium independent interfaces for the network protocol, the medium independent interfaces defining a particular bus configuration, and further include connectors coupled to the medium independent interfaces adapted to receive cables configured according to the particular bus configuration.