Transport of control and data traffic for multicast virtual private networks

• US 8,068,492 B1
• Filed: 04/21/2009
• Issued: 11/29/2011
• Est. Priority Date: 08/30/2004
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Rekhter, Yakov, Aggarwal, Rahul, Lohiya, Anil
• Primary Examiner(s): Ryman; Daniel J
• Assistant Examiner(s): Patel; Jay P
• Application Number:
  US12/427,542
• Time in Patent Office: 952 Days
• Field of Search: 370/230, 370/256, 370/390, 370/432, 709/230
• US Class Current: 370/390
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• 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

Principles of the invention are described for providing multicast virtual private networks (MVPNs) across a public network that are capable of carrying high-bandwidth multicast traffic with increased scalability. In particular, the MVPNs may transport layer three (L3) multicast traffic, such as Internet Protocol (IP) packets, between remote sites via the public network. The principles described herein may reduce the overhead of protocol independent multicast (PIM) neighbor adjacencies and customer control information maintained for MVPNs. The principles may also reduce the state and the overhead of maintaining the state in the network by removing the need to maintain at least one dedicated multicast tree per each MVPN.

Claims

1. A method comprising:

using a first tunneling protocol, establishing a multicast tree having a source router providing an ingress to the multicast tree and a plurality of destination routers providing a plurality of different egresses from the multicast tree within a network, wherein each of the destination routers belongs to at least one multicast virtual private network (MVPN); and

using a second tunneling protocol different from the first tunneling protocol, establishing tunnels between the source router and the one or more destination routers;

separately transporting control information and multicast data packets for the MVPNs between the source router and the one or more destination routers, wherein separately transporting the control information and the multicast data packets comprises;

transporting the multicast data packets from the source router to the destination routers on the multicast tree in accordance with the first tunneling protocol, and

transporting the control information between the source router and the destination routers using the tunnels in accordance with the second tunneling protocol.

2. The method of claim 1, wherein transporting the control information comprises:

generating advertisements in accordance with a routing protocol;

encoding within the advertisements the control information for the MVPNs to form encoded advertisements, wherein the control information encoded within the advertisements includes join or prune messages;

in accordance with the second tunneling protocol, encapsulating the advertisements encoded with the control information to form packets; and

transmitting the packets containing the encoded advertisements along the tunnels to communicate the control information between the source router and the destination routers.

3. The method of claim 2, wherein encapsulating the advertisements comprises encapsulating the advertisements with multi-protocol label switching (MPLS) labels to form MPLS packets that contain the advertisements encoded with the control information.

4. The method of claim 1,

wherein transporting the control information comprises exchanging the control information for the MVPNs with a reliable transport protocol that substantially eliminates periodic refresh of the control information by using advertisements generated in accordance with the reliable transport protocol to communicate the control information, and

wherein the control information includes customer join and prune messages.

5. The method of claim 4, wherein the reliable transport protocol comprises protocol independent multicast (PIM) extended to include a refresh reduction mechanism.

6. The method of claim 4, wherein the reliable transport protocol comprises the border gateway protocol (BGP).

7. The method of claim 1, wherein transporting the multicast data packets comprises:

receiving the multicast data packets from a multicast source;

encapsulating the multicast data packets for the MVPNs that have destination routers requesting the multicast data packets; and

transmitting the encapsulated packet for the MVPNs on the multicast tree.

8. The method of claim 7, wherein encapsulating the multicast data packets comprises encapsulating the multicast data packets using Internet Protocol (IP) encapsulation.

9. The method of claim 8, wherein encapsulating the multicast data packets comprises encapsulating the multicast data packets using Multi-Protocol Label Switching (MPLS) encapsulation.

10. A router comprising:

a control unit providing an operating environment for a plurality of protocols,

a first tunneling protocol executing on the control unit configured to establish a multicast tree having a source router providing an ingress to the multicast tree and a plurality of destination routers providing a plurality of different egresses from the multicast tree, each of the destination routers belonging to at least one multicast virtual private network (MVPN); and

a second tunneling protocol executing on the control unit and configured to establish a tunnel to at least one of the source router and the destination routers,

wherein the control unit is configured to transport multicast data packets for at least one of the MVPNs on the multicast tree in accordance with the first tunneling protocol and transport control information for the MVPN using the tunnel in accordance with the second tunneling protocol.

11. The router of claim 10, wherein the control unit comprises:

a routing protocol configured to generate routing advertisements in accordance with the routing protocol;

a device-device exchange module configured to encode within the routing advertisements the control information for the MVPNs to form encoded routing protocol advertisements, wherein the control information encoded within the advertisements includes join or prune messages associated with the MVPNs;

wherein the control unit is configured to encapsulate the routing protocol advertisements in accordance with the second tunneling protocol to form packets and transmit the packets containing the encoded advertisements along the tunnel to communicate the control information to one of the source router and the destination routers.

12. The router of claim 11, further comprising a device-device exchange module that establishes the tunnels between the source router and the destination routers and transmits the control information on the tunnels.

13. The router of claim 12, wherein the device-device exchange module exchanges the control information for the MVPNs with a reliable transport protocol that substantially eliminates periodic refresh of the control information information by using advertisements generated in accordance with the reliable transport protocol and that encode customer join and prune messages.

14. The router of claim 13, wherein the reliable transport protocol comprises one of the border gateway protocol (BGP) or protocol independent multicast (PIM) extended to include a refresh reduction mechanism.

15. The router of claim 10, wherein the control unit:

receives the multicast data packets from a multicast source;

encapsulates the multicast data packets for the MVPNs that have destination routers requesting the multicast data packets; and

transmits the encapsulated packet for the MVPNs on the multicast tree.

16. The router of claim 15, wherein the encapsulated packet comprises one of an Internet Protocol (IP) encapsulated packet or a multi-protocol label switching (MPLS) encapsulated packet.

17. A non-transitory computer-readable medium comprising instructions that cause a programmable processor to:

using a first tunneling protocol, establish a multicast tree having a source router providing an ingress to the multicast tree and a plurality of destination routers providing a plurality of different egresses from the multicast tree, wherein each of the destination routers belongs to at least one multicast virtual private network (MVPN);

using a second tunneling protocol different from the first tunneling protocol, establish tunnels between the source router and the destination routers;

receive a customer join and prune messages for the MVPNs;

in response to the customer join and prune messages, generate routing protocol advertisements in accordance with a routing protocol;

encode within the advertisements the join and prune messages to form encoded advertisements;

in accordance with the second tunneling protocol, encapsulate the routing protocol advertisements to form packets; and

transmit the packets containing the encoded routing protocol advertisements along the tunnels to communicate the join and prune messages to one of the source router and the destination routers.

18. A system comprising:

a source router within a network;

a plurality of destination routers within the network, wherein each of the destination routers belongs to at least one multicast virtual private network (MVPN);

a multicast tree established within the network in accordance with a first tunneling protocol to transmit multicast data packets for the MVPNs from the source router to the destination routers; and

tunnels established between the source router and the destination routers in accordance with a second tunneling protocol to transmit control information for the MVPN,

wherein the tunnels transmit the control information encoded within routing protocol advertisements that conform to a routing protocol, and

wherein the control information includes customer join and prune messages associated with the MVPN.

19. A method comprising:

establishing a multicast tree in accordance with a first tunneling protocol, wherein the multicast tree comprises a source router providing an ingress to the multicast tree and a plurality of destination routers providing a plurality of different egresses from the multicast tree, wherein each of the destination routers belongs to at least one multicast virtual private network (MVPN);

establishing tunnels between the source router and the destination routers in accordance with a second tunneling protocol to transmit control information for the MVPN;

transporting multicast data packets from the source router to the destination device on the multicast tree;

receiving, with one of the source router or the destination routers, at least one of a join message or a prune message for one of the MVPNs;

in response to the at least one of a join message or a prune message, generating a routing protocol advertisement in accordance with a routing protocol;

encoding within the advertisements at least one of a join message or a prune messages to form an encoded advertisement;

encapsulating the routing protocol advertisement to form a packet; and

transmitting the packet containing the encoded routing protocol advertisements along the tunnels to communicate the at least one of a join message or a prune message.