Distributed server functionality for emulated lan

• US 20040205188A1
• Filed: 04/01/2004
• Published: 10/14/2004
• Est. Priority Date: 06/27/2001
• Status: Active Grant

• Current Assignee: Hyglo Systems AB
• Original Assignee: Hyglo Systems AB
• Inventors: Ahlard, David T, Hansson, Urban Erik, Bystrom, Leif J.B., Bergkvist, Joakim
• Granted Patent: US 7,461,157 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: H04L 12/1854 with non-centralised forwarding system, e.g. chaincast
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272

Abstract

A system for emulating a local are network on top of a global communication network (4), the system comprising clients units (LEC) and a server (LES) which are connected to said global network (4), and a broadcast functionality (BUS) for relaying messages to all clients in the emulated local area network. The system is characterized in that said broadcast functionality is distributed and implemented in more than one network unit node in the emulated local area network. The global network is preferably an IP network, such as the Internet, and act as a backbone for the emulated local area network.

Claims

1. System for emulating a local area network on top of a global communication network, where the system comprising clients units and a server which are connected to said global network, and said server initially is configured with predetermined performance criteria, and a broadcast functionality for relaying messages to all clients in the emulated local area network, wherein said server defines which clients units has an up and running broadcast functionality based on predetermined performance criteria wherein said broadcast functionality is distributed and implemented in more than one network unit node in the emulated local area network.

3. The system as recited in claim 1, wherein a master and initial broadcast functionality unit is configured in said server.

5. The system as recited in claim 1, wherein the connections between the nodes of the emulated local area network may is implemented as a multicast network transmitted through the global network.

7. The system as recited in claim 1, wherein the connections between the nodes of the emulated local area network may is implemented as single-cast addresses, forming tunnels through said global network.

9. The system as recited in claim 1, wherein each network unit having a distributed broadcasting functionality comprises means for executing an algorithm for preventing broadcast messages from being indefinitely sent between the network unit nodes having the distributed broadcasting functionality.

11. The system as recited in claim 9, wherein said algorithm is based on a checksum of the broadcast packet, which checksum uniquely identifies the broadcast packet and is cached by the broadcasting functionality for the purpose of dropping subsequently arriving broadcast packets having the same checksum.

13. The system as recited in claim 9, wherein said algorithm is based on a hop counter which is decremented by each broadcasting functionality unit upon arrival, said algorithm functioning to drop subsequent incoming packets when the counter has reached zero.

15. The system as recited in claim 1, wherein the global network acts as a backbone for the emulated local area network.

17. The system as recited in claim 15, wherein said global network Internet Protocol network is an example of such a global network.

2. System for emulating a local area network on top of a global communication network, where the system comprising clients units and a server which are connected to said global network, and a broadcast functionality for relaying messages to all clients in the emulated local area network, wherein said distributed broadcast functionality is hierarchically structured wherein said broadcast functionality is distributed and implemented in more than one network unit node in the emulated local area network.

4. The system as recited in claim 2, wherein a master and initial broadcast functionality unit is configured in said server.

6. The system as recited in claim 2, wherein the connections between the nodes of the emulated local area network may is implemented as a multicast network transmitted through the global network.

8. The system as recited in claim 2, wherein the connections between the nodes of the emulated local area network may is implemented as single-cast addresses, forming tunnels through said global network.

10. The system as recited in claim 2, wherein each network unit having a distributed broadcasting functionality comprises means for executing an algorithm for preventing broadcast messages from being indefinitely sent between the network unit nodes having the distributed broadcasting functionality

12. The system as recited in claim 10, wherein said algorithm is based on a checksum of the broadcast packet, which checksum uniquely identifies the broadcast packet and is cached by the broadcasting functionality for the purpose of dropping subsequently arriving broadcast packets having the same checksum.

14. The system as recited in claim 10, wherein said algorithm is based on a hop counter which is decremented by each broadcasting functionality unit upon arrival, said algorithm functioning to drop subsequent incoming packets when the counter has reached zero.

16. The system as recited in claim 2, wherein the global network acts as a backbone for the emulated local area network.

18. The system as recited in claim 16, wherein said global network Internet Protocol network is an example of such a global network.