Data communication system and method for same

Abstract

A Provider Edge PE3 replicates a received packet and relays these to virtual circuits VC1, VC2 respectively, and Provider Edges PE2, PE2 respectively receive the packets from the virtual circuits VC1, VC2, whereupon the Provider Edges PE2, PE2, on the basis of an agreement between them, decide to handle the received packets such that one of the edges relays the packet to a Customer Edge CE1 for forwarding to a Host A, while the other edge discards the packet without relaying it to the Customer Edge CE1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of a network in which the data communication system of the invention is implemented;

FIG. 2 is a block diagram depicting a switch arrangement that can be used as a customer edge or a provider edge;

FIG. 3A is an illustration depicting the operation of setting up a virtual circuit (VC) in Embodiment 1 of the invention; FIG. 3B is an illustration depicting normal operation in Embodiment 1 of the invention; FIG. 3C is an illustration depicting normal operation in Embodiment 1 of the invention;

FIG. 4A is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during setup operation of a virtual circuit (VC) in Embodiment 1 of the invention; FIG. 4B is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during normal operation of a virtual circuit (VC) in Embodiment 1 of the invention;

FIG. 5A is an illustration depicting operation when a failure occurs in Embodiment 1 of the invention; FIG. 5B is an illustration depicting operation when a failure occurs in Embodiment 1 of the invention; FIG. 5C is an illustration depicting operation during recovery in Embodiment 1 of the invention;

FIG. 6A is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during operation when a failure occurs in Embodiment 1 of the invention; FIG. 6B is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during operation during recovery in Embodiment 1 of the invention;

FIG. 7A is an illustration depicting the operation of setting up a virtual circuit (VC) in Embodiment 2 of the invention; FIG. 7B is an illustration depicting normal operation in Embodiment 2 of the invention; FIG. 7C s an illustration depicting normal operation in Embodiment 2 of the invention; FIG. 7D is an illustration depicting normal operation in Embodiment 2 of the invention; FIG. 7E is an illustration depicting normal operation in Embodiment 2 of the invention;

FIG. 8A is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during setup operation of a virtual circuit (VC) in Embodiment 2 of the invention; FIG. 8B is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during normal operation of a virtual circuit (VC) in Embodiment 2 of the invention; FIG. 8C is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during normal operation of a virtual circuit (VC) in Embodiment 2 of the invention;

FIG. 9A is an illustration depicting operation when a failure occurs in Embodiment 2 of the invention; FIG. 9B is an illustration depicting operation when a failure occurs in Embodiment 2 of the invention; FIG. 9C is an illustration depicting operation during recovery in Embodiment 2 of the invention;

FIG. 10A is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during operation when a failure occurs in Embodiment 2 of the invention; FIG. 10B is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during operation when a failure occurs in Embodiment 2 of the invention; FIG. 10C is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during operation during recovery in Embodiment 2 of the invention;

FIG. 11A is an illustration depicting the operation of setting up a virtual circuit (VC) in Embodiment 3 of the invention; FIG. 11B is an illustration depicting normal operation in Embodiment 3 of the invention; FIG. 11C is an illustration depicting normal operation in Embodiment 3 of the invention;

FIG. 12A is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during setup operation of a virtual circuit (VC) in Embodiment 3 of the invention; FIG. 12B is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during normal operation of a virtual circuit (VC) in Embodiment 3 of the invention; FIG. 12C is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during normal operation of a virtual circuit (VC) in Embodiment 3 of the invention;

FIG. 13A is an illustration depicting operation when a failure occurs in Embodiment 3 of the invention; FIG. 13B is an illustration depicting operation when a failure occurs in Embodiment 3 of the invention; FIG. 13C is an illustration depicting operation during recovery in Embodiment 3 of the invention;

FIG. 14A is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during operation when a failure occurs in Embodiment 3 of the invention; FIG. 14B is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during operation when a failure occurs in Embodiment 3 of the invention; FIG. 14C is an illustration of management tables prepared in Provider Edges PE1, PE2, and PE3 respectively during operation during recovery in Embodiment 3 of the invention;

FIG. 15 is a block diagram depicting an arrangement where multi-device link aggregation is implemented on two network devices;

FIG. 16 is an illustration of an example of a network in which multi-device link aggregation is implemented on VPLS;

FIG. 17 is an illustration depicting setup of virtual circuits VC linking a User 1 network and a User 2 network; and

FIG. 18 is an illustration depicting packet proliferation.

Claims

1. A data communication system for communicating data between a second and a third network via a first network, the system comprising: a first and a second edge present within the first network, for which multi-device link aggregation is implemented;a third edge present within the first network, connected to the first edge via a first virtual circuit and connected to the second edge via a second virtual circuit;a fourth edge present within the second network, connected to the first and second edges by circuits and connected to a host within the second network; anda fifth edge present within the third network, connected to the third edge by a circuit and connected to a host within the third network;wherein in the event of forwarding of a packet from a host in the third network to a host in the second network,the third edge receives the packet sent from the host in the third network via the fifth edge, replicates the packet, and relays these individually to the first and second virtual circuits; andthe first edge receives the packet sent from the first virtual circuit while the second edge receives the packet sent from the second virtual circuit, and the first and second edges decide upon the handling of the received packets on the basis of an agreement between them in advance, whereby one of the edges relays the received packet to the fourth edge for forwarding to the host in the second network, while the other edge discards the received packet without relaying it to the fourth edge.

2. The data communication system according to claim 1 wherein in the third edge settings are made so as to not perform MAC learning with respect to packet forwarding via the first and second virtual circuits.

3. The data communication system according to claim 1 wherein during setup of the first and second virtual circuits individually connected to the third edge,the first and second edges each establish the agreement, which relates to handling of packets received via the first and second virtual circuits being set up, between the first and second edges and each send to the third edge a virtual circuit setup message, andthe third edge is instructed to not perform MAC learning with respect to packet forwarding via the first and second virtual circuits being set up by the message.

4. The data communication system according to claim 1 wherein in the event that one edge of the first and second edges fails and the failure is detected by the other edge of the first and second edges,the failure detecting edge updates the agreement such that the packets received from the connected virtual circuit are relayed to the fourth edge.

5. The data communication system according to claim 4 wherein in the event that the failure detecting edge receives a packet sent from the connected virtual circuit after the agreement is updated,the failure detecting edge decides on the handling of the received packet on the basis of the updated agreement, and relays the received packet to the fourth edge.

6. The data communication system according to claim 4 wherein in the event that the failed edge recovers from the failure,the first and second edges renegotiate an agreement relating to the handling by the first and second edges of packets received respectively from the first and second virtual circuits,the recovered edge sends a virtual circuit setup message to the third edge, andthe third edge is instructed to not perform MAC learning with respect to packet forwarding via the virtual circuit being set up by the message.

7. A data communication system for communicating data between a second and a third network via a first network, the system comprising: a first and a second edge present within the first network, for which multi-device link aggregation is implemented;a third edge present within the first network, connected to the first edge via a first virtual circuit and connected to the second edge via a second virtual circuit;a fourth edge present within the second network, connected to the first and second edges by circuits and connected to a host within the second network; anda fifth edge present within the third network, connected to the third edge by a circuit and connected to a host within the third network;wherein in the event of forwarding of a packet from a host in the third network to a host in the second network,the third edge receives the packet sent from the host in the third network via the fifth edge, and on the basis of MAC learning content relating to packet transmission, relays the packet to either the first or second virtual circuit; andthe edge that receives the packet from the connected virtual circuit, of the first and second edges, relays the received packet to the fourth edge for forwarding to the host in the second network.

8. The data communication system according to claim 7 wherein an agreement is negotiated in advance between the first edge and the second edge with regard to handling of packets received via the first and second virtual circuits, andin the event that a packet is forwarded from a host in the second network to a host in the third network,when one edge of the first and second edges receives the packet sent from the host in the second network via the fourth edge, the one edge acquires from the received packet the destination and sender combination, interchanges the destination and the sender to derive a first new combination, in the event that the agreement specifies with respect to handling of the packet of the first new combination that the packet be relayed, the one edge relays the received packet to the connected virtual circuit, and in the event that the agreement specifies with respect to handling of the packet of the first new combination that the packet be discarded, the one edge sends the received packet to the other edge of the first and second edges.

9. The data communication system according to claim 8 wherein when the other edge of the first and second edges receives the packet sent from the one edge, the other edge acquires the destination and sender combination from the received packet and interchanges the destination and the sender thereof to derive a second new combination, andin the event that the agreement specifies with respect to handling of the packet of the second new combination that the packet be relayed, the other edge relays the received packet to the connected virtual circuit.

10. The data communication system according to claim 8 wherein in the third edge settings are made so as to perform MAC learning with respect to packet forwarding via the first and second virtual circuits, andin the event of receiving a the packet from the first or second virtual circuit, the third edge performs MAC learning with respect to forwarding of the received packet on the basis of the settings, acquires the MAC learning content and relays the received packet to the fifth edge.

11. The data communication system according to claim 9 wherein in the third edge settings are made so as to perform MAC learning with respect to packet forwarding via the first and second virtual circuits, andin the event of receiving a the packet from the first or second virtual circuit, the third edge performs MAC learning with respect to forwarding of the received packet on the basis of the settings, acquires the MAC learning content and relays the received packet to the fifth edge.

12. The data communication system according to claim 7 wherein during setup of the first and second virtual circuits individually connected to the third edge,the first and second edges each establish the agreement, which relates to handling of packets received via the first and second virtual circuits being set up, between the first and second edges and each send to the third edge a virtual circuit setup message, andthe third edge is instructed to perform MAC learning with respect to packet forwarding via the first and second virtual circuits being set up by the message.

13. The data communication system according to claim 7 wherein in the event that one edge of the first and second edges fails and the failure is detected by the other edge of the first and second edges,the failure detecting edge updates the agreement such that the packets received from the connected virtual circuit are relayed to the fourth edge and sends a cancel message to the third edge, andthe third edge is instructed to delete MAC learning content with respect to packet forwarding via the virtual circuit connected to the failed edge by the cancel message.

14. The data communication system according to claim 13 wherein in the event that the failure detecting edge receives a packet sent from the connected virtual circuit after the agreement is updated,the failure detecting edge decides on the handling of the received packet on the basis of the updated agreement, and relays the received packet to the fourth edge.

15. The data communication system according to claim 13 wherein in the event that the failed edge recovers from the failure,the first and second edges renegotiate an agreement relating to the handling by the first and second edges of packets received respectively from the first and second virtual circuits,the recovered edge sends a virtual circuit setup message to the third edge,the third edge is instructed to perform MAC learning with respect to packet forwarding via the virtual circuit being set up by the message,the recovered edge sends a cancel message to the third edge, andthe third edge is instructed to delete MAC learning content with respect to forwarding of specific packet by the cancel message.

16. The data communication system according to claim 7 wherein an agreement is negotiated in advance between the first edge and the second edge with regard to handling of packets received via the first and second virtual circuits;in the event that a packet is forwarded from a host in the second network to a host in the third network,when one edge of the first and second edges receives the packet sent from the host in the second network via the fourth edge, the one edge acquires from the received packet the destination and sender combination, interchanges the destination and the sender to derive a new combination, and updates the agreement so that the packet of the new combination is relayed;the one edge instructs the other edge to update the agreement so that the packet of the new combination is discarded, and instructs the third edge with MAC learning content so that the packet of this new combination is sent to the virtual circuit connected to the one edge;the one edge relays the received packet to the connected virtual circuit;in the third edge settings are made so as to not perform MAC learning with respect to packet forwarding via the first and second virtual circuits; andin the event that receives a the packet from the first or second virtual circuit, the third edge does not perform MAC learning with respect to forwarding of the received packet on the basis of the settings, and relays the received packet to the fifth edge.

17. The data communication system according to claim 16 wherein in the event of packet forwarding from a host in the third network to a host in the second network,the edge receiving the packet from a connected virtual circuit of the first and second edges, relays the received packet to the fourth edge on the basis of the updated agreement.

18. The data communication system according to claim 13 wherein in the event that the failed edge recovers from the failure,the first and second edges renegotiate an agreement relating to the handling by the first and second edges of packets received respectively from the first and second virtual circuits,the recovered edge sends a virtual circuit setup message to the third edge,the third edge is instructed to perform MAC learning with respect to packet forwarding via the virtual circuit being set up by the message,the recovered edge sends a cancel message to the third edge, andthe third edge is instructed to delete MAC learning content with respect to forwarding of specific packet by the cancel message.

19. A data communication method for communicating data between a second and a third network via a first network using a data communication system, the system comprising:a first and a second edge present within the first network, for which multi-device link aggregation is implemented;a third edge present within the first network, connected to the first edge via a first virtual circuit and connected to the second edge via a second virtual circuit;a fourth edge present within the second network, connected to the first and second edges by circuits and connected to a host within the second network; anda fifth edge present within the third network, connected to the third edge by a circuit and connected to a host within the third network;wherein in the event of forwarding of a packet from a host in the third network to a host in the second network,the data communication method comprises the following steps:(a) the third edge receiving the packet sent from the host in the third network via the fifth edge, replicating the packet, and relaying these individually to the first and second virtual circuits;(b) the first edge receiving the packet sent from the first virtual circuit, and the second edge receiving the packet sent from the second virtual circuit; and(c) the first and second edges deciding upon the handling of the received packets on the basis of an agreement between them in advance, whereby one of the edges relays its received the packet to the fourth edge for forwarding to the host in the second network, while the other edge discards its received packet without relaying it to the fourth edge.

20. A data communication method for communicating data between a second and a third network via a first network using a data communication system, the system comprising:a first and a second edge present within the first network, for which multi-device link aggregation has been implemented;a third edge present within the first network, connected to the first edge via a first virtual circuit and connected to the second edge via a second virtual circuit;a fourth edge present within the second network, connected to the first and second edges by circuits and connected to a host within the second network; anda fifth edge present within the third network, connected to the third edge by a circuit and connected to a host within the third network;wherein in the event of forwarding of a packet from a host in the third network to a host in the second network,the data communication method comprises the following steps:(a) the third edge receiving the packet sent from the host in the third network via the fifth edge, and on the basis of MAC learning content relating to packet transmission, relaying the packet to either the first or second virtual circuit; and(b) the edge that receives the packet from the connected virtual circuit of the first and second edges, relaying the received packet to the fourth edge for forwarding to the host in the second network.