Network having secure fast packet switching and guaranteed quality of service

• US 5,485,455 A
• Filed: 01/28/1994
• Issued: 01/16/1996
• Est. Priority Date: 01/28/1994
• Status: Expired due to Term

• Current Assignee: Enterasys Networks Incorporated (Extreme Networks, Inc.)
• Original Assignee: Cabletron Systems Incorporated (Extreme Networks, Inc.)
• Inventors: Dobbins, Kurt, Oliver, Chris, Jeffords, Jason, Parker, Tom, Dev, Roger, Andlauer, Phil, Nutbrown, Bruce, Grimes, Andy, Hullette, Dan
• Primary Examiner(s): Kizou, Hassan
• Application Number:
  US08/188,238
• Time in Patent Office: 718 Days
• Field of Search: 370/60, 370/60.1, 370/94.1, 370/94.2, 370/94.3, 370/85.13, 370/85.14, 340/825.52, 340/825.53, 395/200, 395/325, 395/725, 364/286.5
• US Class Current: 370/255
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket
• CPC Class Codes: H04L 2012/5619 Network Node Interface, e.g. tandem connections, transit switching
• CPC Class Codes: H04L 2012/5626 Network management, e.g. Intelligent nets
• CPC Class Codes: H04L 2012/5631 Resource management and allocation
• CPC Class Codes: H04L 2012/564 Connection-oriented
• CPC Class Codes: H04L 2012/5645 Connectionless
• CPC Class Codes: H04L 2012/5665 Interaction of ATM with other protocols
• CPC Class Codes: H04L 45/10 Routing in connection-oriented networks, e.g. X.25 or ATM
• CPC Class Codes: H04L 45/36 Backward learning
• CPC Class Codes: H04L 49/203 ATM switching fabrics with multicast or broadcast capabilities
• CPC Class Codes: H04L 49/256 Routing or path finding in ATM switching fabrics
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

Apparatus and method for establishing "virtual connections" through a packet switched data communications network, the network including a plurality of end systems and switches connected by links. Each end system has a unique physical layer address and each switch has a connection database of valid connections between different ports on the switch and a switching mechanism for establishing temporary connections. Each switch is registered with a connection server such that, prior to transmission of a connectionless datagram from a first end system to a second end system, a path of valid connections through one or more switches from the first end system to the second end system is determined by configuring the connection table of each switch on the path with a connection identifier identified by the physical layer addresses of the first and second end systems, and wherein the data packet remains as a connectionless datagram. In other aspects, an improved method is providing for allocating bandwidth among competing devices requesting access to a bandwidth limited shared resource (e.g., the previously defined switch), and to a search method for making a best path determination through the network based on a number of constraints.

Claims

1. In a packet switched data communications network, the network including a plurality of end systems and switches connected by links, each switch having at least one network port connected to another switch and some switches having access ports connected to end systems, and each end system having a unique physical layer address, each switch including a connection database of valid connections between different ports on the switch and a switching mechanism for establishing temporary connections between the different ports on the switch, the improvement comprising:

a connection server coupled to each switch,

means coupled to each switch and the connection server for registering each switch with the connection server, and

means, prior to transmission of a data packet comprising a connectionless datagram from a first end system having a first physical layer address to a second end system having a second physical layer address, for determining a path from the first end system to the second end system through one or more of the switches and for configuring the connection database of each respective switch on the path with a connection identifier including the first physical layer address and the second physical layer address of the first and second end systems, respectively,

the determining and configuring means being coupled to each switch and the connection server, and the data packet remaining as a connectionless datagram as the data packet is transmitted through the respective switches along the path.

2. The network of claim 1, wherein the connection identifier further includes:

an input port address of the respective switch on which the data packet arrives, and

which connection identifier is mapped to an output port of the respective switch on which the data packet exits the switch.

3. The network of claim 1, further including means for deleting the connection identifier from the connection database after a predetermined time.

4. The network of claim 2, wherein each switch includes address learning means for pairing the first physical layer address within an incoming data packet with the input port address on which the packet arrives at the respective switch, thereby generating a source address pair comprising the input port address and the first physical layer address, and the registering means includes a directory of source address pairs for end systems in the network.

5. The network of claim 1, wherein each switch includes means for storing the data packet while the path is determined and the switches along the path are configured.

6. The network of claim 1, wherein the means for determining includes means for extracting from a data packet, which data packet does not contain the second physical layer address of the second end system, higher layer protocol information and determining the second physical layer address of the second end system for which the data packet is intended.

7. The network of claim 6, wherein the means for determining further includes means for sending a reply to the first end system comprising the second physical layer address of the second end system.

8. The network of claim 1, wherein each switch includes means for sending a connection setup request to the connection server for starting the determining means.

9. The network of claim 1, wherein the connection server is external to the switches.

10. The network of claim 1, wherein the determining and configuring means configures the connection database of at least one of the switches to send the data packet from one input port of the switch to more than one output port of the switch.

11. The network of claim 1, wherein the determining and configuring means includes:

means for authorizing valid connections between the first and second end systems.

12. The network of claim 11, wherein the authorizing means includes:

a directory database of authorized valid connections between first and second end systems; and

means for accessing the directory database to determine if there is an authorized valid connection.

13. The network of claim 1, wherein the determining and configuring means includes:

means for determining a best path of valid connections from the first end system to the second end system through the switches of the network.

14. The network of claim 13, wherein the means for determining the best path utilizes a number of constraints including one or more of:

bandwidth;

cost;

QOS (quality of service); and

a maximum number of connections.

15. The network of claim 1, wherein the determining and configuring means includes:

means for determining the valid connections based on an application of time varying or differing constraints.

16. The network of claim 1, further including means for allocating a specified bandwidth to the valid connections.

17. The network of claim 1, including a management information database for controlling the switches.

18. The network of claim 1, further comprising a network management system which provides at least one of the following services:

a) determination of a best path between first and second end systems;

b) designation of authorized valid connections between first and second end systems;

c) determination of the location of end systems;

d) accounting of each end system'"'"'s usage of the network based on the number of data packet or byte transmissions; and

e) designation of a specified bandwidth for valid connections between designated end systems.

19. The network of claim 1, wherein the physical layer address is a MAC address.

20. The network of claim 1, wherein the determining and configuring means includes:

call setup means for configuring the switches on the path with the valid connections;

data transfer means for forwarding one or more data packets on the path; and

call release means for terminating the valid connections on the path.

21. A method of controlling switches and transmitting data packets in a packet switched data communications network, the network including a plurality of end systems and switches connected by links, each switch having at least one network port connected to another switch and some switches having access ports connected to end systems, and each end system having a unique physical layer address, the method comprising the steps of:

prior to transmission of a data packet comprising a connectionless datagram from a first end system having a first physical layer address to a second end system having a second physical layer address, determining a first path from the first end system to the second end system through a plurality of switches based on the physical layer addresses of the first and second end systems, and

configuring the plurality of switches on the first path to enable transmission of the data packet, wherein

the data packet remaining as a connectionless datagram as the data packet is transmitted through the respective switches along the path.

22. The method of claim 21, wherein the configuring step comprises:

providing each switch in the first path with a connection identifier for the data packet, the connection identifier including an input port address of the respective switch, a first physical layer address of the first end system, and a second physical layer address of the second end system, and mapping the connection identifier to an output port of the respective switch.

23. The method of claim 22, wherein each switch has a connection database and the configuring step includes entering the connection identifier in the connection database of each respective switch on the first path.

24. The method of claim 23, further including the step of deleting the connection identifier from the connection database of the respective switch after a predetermined time.

25. The method of claim 23, wherein, once the first path has been determined, multiple data packets having the same connection identifier are transmitted through the network by accessing the respective connection databases in the respective switches on the first path, without redetermining the first path.

26. The method of claim 21, wherein the determining step includes determining a second path for transmission of a data packet from the first end system to a third end system, different from the second end system, and configuring each of the switches on the first path and the second path.

27. The method of claim 21, wherein the determining step includes pairing the first physical layer address within an incoming data packet with the input port address on which the packet arrives at the respective switch to determine a source address pair, and

registering the source address pair in a central directory for the end systems in the network.

28. The method of claim 21, wherein the determining step is initiated when the data packet enters a first switch adjacent to the first end system, and the data packet is stored during the determining and configuring steps.

29. The method of claim 21, wherein the determining step includes, when a first switch receives a broadcast data packet, extracting higher layer protocol information from within the broadcast data pocket to determine the second physical layer address of the second end system for which the broadcast data packet is intended.

30. The method of claim 21, wherein the determining step includes, when a first switch receives a data packet having an unknown connection identifier for the first physical address and the second physical layer address, extracting higher layer protocol information from within the data packet to determine the second end system for which the data packet is intended.

31. The method of claim 30, further including the first switch sending a reply back to the first end system with the second physical layer address of the second end system.

32. The method of claim 21, wherein the determining step includes sending a connection set-up request to a connection service for determining the path and configuring the switches.

33. The method of claim 21, wherein the configuring step includes configuring at least one of the switches to send the data packet from one input port of the switch to more than one output port of the switch.

34. The method of claim 21, wherein at least one of the switches on the path transmits data packets received from different first end systems but intended for one second end system, out different ports.