Virtual private LAN service using a multicast protocol

• US 20040037279A1
• Filed: 08/23/2002
• Published: 02/26/2004
• Est. Priority Date: 08/23/2002
• Status: Active Grant

• Current Assignee: Corrigent Corporation
• Original Assignee: Corrigent Systems Ltd. (Orckit-Corrigent )
• Inventors: Menahemi, Zvi, Bruckman, Leon, Zelig, David, Mor, Gal
• Granted Patent: US 7,339,929 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/1836 with heterogeneous network architecture
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• 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
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]

Abstract

A method for data broadcast over a network includes receiving at a virtual bridge a data packet to be flooded over the network, and passing the data packet from the virtual bridge to a multicast-capable router, along with a broadcast indication. Responsive to the broadcast indication, the router determines a group of destination addresses to which the packet should be multicast, and creates copies of the packet for transmission over the network to the destination addresses in the group.

Claims

1. A method for data broadcast over a network, comprising:

receiving at a virtual bridge a data packet to be flooded over the network;

passing the data packet from the virtual bridge to a multicast-capable router, along with a broadcast indication;

responsive to the broadcast indication, determining at the router a group of destination addresses to which the packet should be multicast;

creating copies of the packet at the router for transmission to the destination addresses in the group; and

transmitting the copies of the packet over the network.

2. A method according to claim 1, wherein transmitting the copies of the packet comprises transmitting the copies of the packet by tunneling through the network.

3. A method according to claim 2, wherein transmitting the copies of the packet by tunneling comprises creating a virtual private LAN service (VPLS), and transmitting the copies of the packet using the VPLS.

4. A method according to claim 3, wherein the virtual bridge comprises a provider edge (PE) device, and wherein transmitting the copies of the packet over the VPLS comprises transmitting the copies of the packet over pseudo-wires (PWs) connecting to the PE device.

5. A method according to claim 4, wherein transmitting the copies over the PWs comprises sending the copies using multi-protocol label-switched (MPLS) tunnels.

6. A method according to claim 4, wherein transmitting the copies over the PWs comprises sending the copies using Generic Routing Encapsulation (GRE).

7. A method according to claim 4, wherein transmitting the copies over the PWs comprises sending the copies using a Layer Two Tunneling Protocol (L2TP).

8. A method according to claim 3, wherein receiving the data packet comprises receiving the data packet at the virtual bridge for transmission on a designated VPLS instance, among a plurality of VPLS instances existing on the network, and wherein creating the copies comprises including in the copies of the packet a field identifying the designated VPLS instance.

9. A method according to claim 1, wherein the multicast-capable router comprises an Internet Protocol (IP) router, and wherein the broadcast indication comprises an IP multicast destination address.

10. A method according to claim 1, wherein receiving the data packet comprises receiving an Ethernet frame.

11. A method according to claim 1, wherein the virtual bridge has one or user-side ports, connecting the virtual bridge to user nodes, and one or more virtual ports, connecting the virtual bridge to other virtual bridges in the network, and

wherein determining the group of the destination addresses comprises choosing a first group of the destination addresses if the packet is received from one of the user nodes, and a second group of the destination addresses if the packet is received from one of the other virtual bridges.

12. A method according to claim 11, wherein the network comprises a virtual private network (VPN), and wherein the first group comprises the destination addresses of all the other virtual bridges participating in the VPN and all the user nodes connected to the user-side ports of the virtual bridge, except the one of the user nodes from which the packet was received, and wherein the second group comprises the user nodes connected to the user-side ports of the virtual bridge while excluding the virtual bridges.

13. A method according to claim 1, wherein passing the data packet to the multicast-capable router comprises passing the data packet from a forwarding engine to a multicast server associated with the virtual bridge, and wherein transmitting the copies comprises returning the copies of the packet from the multicast server to the forwarding engine for transmission by the forwarding engine to the destination addresses.

14. A method according to claim 13, wherein creating the copies comprises addressing one of the copies to each of the destination addresses in the group.

15. A method according to claim 13, wherein the forwarding engine has multiple ports, and wherein creating the copies comprises including in each of the copies of the packet a port identifier field, and wherein transmitting the copies comprises outputting the copies of the packet to the network from the forwarding engine through the ports indicated by the port identifier field.

16. A method according to claim 15, wherein the port identifier field comprises a virtual local area network (VLAN) tag.

17. A method according to claim 1, wherein passing the packet to the multicast-capable router comprises sending the packet from the virtual bridge to a router node in the network, and wherein transmitting the copies comprises multicasting the copies from the router node to the destination addresses in the group.

18. A method according to claim 17, wherein multicasting the copies comprises adding a multiplexing tag to the copies, and comprising determining target users to whom the copies of the packet are to be delivered responsive to the multiplexing tag and to a network source address of the copies of the packet.

19. A method according to claim 1, wherein receiving the data packet comprises reading a medium access control (MAC) destination address of the data packet, and determining that the data packet should be flooded over the network because the MAC destination address is unknown to the virtual bridge.

20. Apparatus for data broadcast over a network, comprising:

a multicast server, which is adapted to receive data packets for multicast over the network, and to create multiple copies of the data packets for transmission to destination addresses in a specified multicast group; and

a forwarding engine, coupled to the multicast server and configured to serve as a virtual bridge having physical and virtual ports, and adapted to send and receive the data packets over the network through the ports, such that upon receiving a data packet to be flooded over the network, the forwarding engine passes the data packet to the multicast server along with a broadcast indication, which causes the server to identify the multicast group to which the copies of the packet should be sent, to generate the copies of the packet for transmission to the destination addresses in the group, and to return the copies of the packet to the forwarding engine, whereupon the forwarding engine transmits the copies of the packet through the ports.

21. Apparatus according to claim 20, wherein the forwarding engine is adapted to transmit the copies of the packet by tunneling through the network.

22. Apparatus according to claim 21, wherein the forwarding engine adapted to transmit the copies of the packet using a virtual private LAN service (VPLS).

23. Apparatus according to claim 22, wherein the forwarding engine is adapted to serve as a provider edge (PE) device, and to transmit the copies of the packet over pseudo-wires (PWs) connecting to the PE device.

24. Apparatus according to claim 23, wherein the PWs comprise multi-protocol label-switched (MPLS) tunnels.

25. Apparatus according to claim 23, wherein the PWs comprise Generic Routing Encapsulation (GRE) tunnels.

26. Apparatus according to claim 23, wherein the PWs comprise Layer Two Tunneling Protocol (L2TP) tunnels.

27. Apparatus according to claim 23, wherein when the data packet is received for transmission on a designated VPLS instance, among a plurality of VPLS instances existing on the network, the forwarding engine is adapted to insert in the copies of the packet a field identifying the designated VPLS instance.

28. Apparatus according to claim 20, wherein the multicast server comprises an Internet Protocol (IP) router, and wherein the broadcast indication comprises an IP multicast destination address.

29. Apparatus according to claim 20, wherein the data packet comprises an Ethernet frame.

30. Apparatus according to claim 20, wherein the ports of the forwarding engine comprise one or more user-side ports, for connecting the forwarding engine to user nodes, and wherein one or more of the virtual ports of the forwarding engine are adapted for connecting the forwarding engine to other virtual bridges in the network, and

wherein the multicast server is adapted to create the multiple copies for transmission to a first group of the destination addresses if the packet is received from one of the user nodes, and to a second group of the destination addresses if the packet is received from one of the other virtual bridges.

31. Apparatus according to claim 30, wherein the network comprises a virtual private network (VPN), and wherein the first group comprises the destination addresses of all the other virtual bridges participating in the VPN and all the user nodes connected to the user-side ports of the forwarding engine, except the one of the user nodes from which the packet was received, and wherein the second group comprises the user nodes connected to the user-side ports of the forwarding engine while excluding the virtual bridges.

32. Apparatus according to claim 20, wherein the multicast server is adapted to address one of the copies of the packet to each of the destination addresses in the group.

33. Apparatus according to claim 20, wherein the forwarding engine has multiple ports, and wherein the multicast server is adapted to insert in each of the copies of the packet a port identifier field, indicating the ports through which the forwarding engine is to output the copies.

34. Apparatus according to claim 33, wherein the port identifier field comprises a virtual local area network (VLAN) tag.

35. Apparatus according to claim 20, wherein the data packets comprise a medium access control (MAC) destination address, and wherein the forwarding engine is adapted to determine that the data packet should be flooded over the network when the MAC destination address of the data packet is unknown to the virtual bridge.

45. A network according to claim 35, wherein the data packet comprises an Ethernet frame.

36. A data communication network, comprising:

one or more multicast routers, which are adapted to receive data packets for multicast over the network, and to create multiple copies of the data packets for transmission to destination addresses in a specified multicast group; and

a plurality of virtual bridges, which have physical and virtual ports and are coupled to send and receive the data packets over the network to and from the multicast routers through the virtual ports, such that any one of the virtual bridges, upon receiving a data packet to be flooded over the network, sends the data packet to one or more of the multicast routers along with a broadcast indication, which causes the routers to identify the multicast group to which the copies of the packet should be sent, to generate the copies of the packet for transmission to the destination addresses in the group, and to transmit the copies of the packet over the network to the destination addresses in the group.

37. A network according to claim 36, wherein the virtual bridge and routers are adapted to transmit the packet and the copies of the packet by tunneling through the network.

38. A network according to claim 37, wherein the virtual bridge and routers are adapted to transmit the packet and the copies of the packet using a virtual private LAN service (VPLS).

39. A network according to claim 38, wherein the virtual bridge is adapted to serve as a provider edge (PE) device, and to transmit the packet over pseudo-wires (PWs) connecting to the PE device.

40. A network according to claim 39, wherein the PWs comprise multi-protocol label-switched (MPLS) tunnels.

41. A network according to claim 39, wherein the PWs comprise Generic Routing Encapsulation (GRE) tunnels.

42. A network according to claim 39, wherein the PWs comprise Layer Two Tunneling Protocol (L2TP) tunnels.

43. A network according to claim 38, wherein when the data packet is received for transmission on a designated VPLS instance, among a plurality of VPLS instances existing on the network, the virtual bridge is adapted to insert in the packet a field identifying the designated VPLS instance.

44. A network according to claim 36, wherein the multicast routers comprise Internet Protocol (IP) routers, and wherein the broadcast indication comprises an IP multicast destination address.

46. A network according to claim 36, wherein the data packets comprise a medium access control (MAC) destination address, and wherein the virtual bridges are adapted to determine that the data packet should be flooded over the network when the MAC destination address of the data packet is unknown.

47. A network according to claim 36, wherein the virtual bridges are adapted to add a multiplexing tag to the copies of the packet, and wherein the virtual bridges receiving the copies of the packet are adapted to determine target users to whom the copies are to be delivered responsive to the multiplexing tag and to a network source address of the copies of the packet.