Reliable exchange of control information for multicast virtual private networks

• US 7,983,261 B1
• Filed: 07/06/2009
• Issued: 07/19/2011
• Est. Priority Date: 08/30/2004
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Lohiya, Anil, Rekhter, Yakov, Aggarwal, Rahul
• Primary Examiner(s): Patel; Jayanti K
• Assistant Examiner(s): CAMPBELL, MATTHEW T
• Application Number:
  US12/497,957
• Time in Patent Office: 743 Days
• Field of Search: None
• 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 tunneling protocol, establishing multicast tree having a source device providing an ingress to the multicast tree and a plurality of destination devices providing a plurality of different egresses from the multicast tree within a network, wherein each of the destination devices belongs to at least one multicast virtual private network (MVPN), and where each of the destination devices is associated with one or more customer networks;

using a routing protocol different from the tunneling protocol, establishing routing communications between the source device and the one or more destination devices;

after establishing the multicast tree, receiving join or prune messages from at least one of the customer networks with one or more of the destination devices;

after establishing the multicast tree and receiving the join or prune messages, generating routing protocol advertisements in accordance with the routing protocol;

encoding, within the routing protocol advertisements, control information for the MVPNs to form encoded advertisements, wherein the control information encoded within the advertisements includes the join or prune messages received from the at least one of the customer networks; and

transmitting the encoded routing protocol advertisements from the destination devices to the source device via the routing protocol to communicate the join or prune messages to the source device of the multicast tree.

2. The method of claim 1, wherein the tunneling protocol comprises a label distribution protocol, wherein multicast tree is a point-to-point (P2MP) label switched path (LSP), wherein the routing protocol comprises the border gateway protocol (BGP), and wherein encoding routing protocol advertisements comprises encoding multicast group join messages within border gateway protocol (BGP) control advertisements.

3. The method of claim 2, wherein encoding the multicast group join messages comprises including a route distinguisher that corresponds to the MVPN to which the multicast group belongs, an address of a multicast source associated with the multicast group, and an address of the multicast group.

4. The method of claim 3, further comprising including a route target attribute of each of the MVPNs mapped to the multicast tree in the control advertisement.

5. The method of claim 1, further comprising:

establishing tunnels between the source device and the one or more destination devices; and

using the routing protocol to transmit the control information on the tunnels.

6. The method of claim 1, wherein transmitting the encoded routing protocol advertisements comprises transmitting the encoded routing protocol advertisements for remotely located virtual routing and forwarding (VRF) instances that correspond to the MVPNs.

7. The method of claim 1, further comprising receiving control information for the MVPNs between the source device and one or more customer networks with the routing protocol.

8. The method of claim 7, wherein receiving control information for the MVPNs between the source device and the one or more customer networks comprises receiving control information from locally located virtual routing and forwarding (VRF) instances of the source device that correspond to the MVPNs.

9. A network device comprising:

one or more network interfaces;

a control unit coupled to the network interfaces;

a tunneling protocol executing on the control unit that establishes a multicast tree having a source device providing an ingress to the multicast tree and a plurality of destination devices providing a plurality of different egresses from the multicast tree within a network, wherein each of the destination devices belongs to at least one multicast virtual private network (MVPN), and wherein each of the destination devices is associated with one or more customer networks;

a routing protocol executing on the control unit that exchanges routing communications between the source device and the one or more destination devices;

a snooping module that snoops multicast control messages between at least one of the destination devices and network devices of the customer networks; and

a device-device exchange module that converts the multicast control messages into routing protocol advertisements that encode the multicast control messages, wherein the device-device exchange module transmits the encoded routing protocol advertisements from the destination devices to the source device via the routing protocol to communicate the multicast control messages to the source device of the multicast tree.

10. The network device of claim 9, wherein the tunneling protocol comprises a label distribution protocol, wherein the multicast tree is a point-to-point (P2MP) label switched path (LSP), wherein the routing protocol comprises the border gateway protocol (BGP), and wherein encoding routing protocol advertisements comprises encoding multicast group join messages within border gateway protocol (BGP) control advertisements.

11. The network device of claim 9, wherein the device-device exchange module transmits the encoded routing protocol advertisements between remotely located virtual routing and forwarding (VRF) instances that correspond to the MVPNs.

12. The network device of claim 9, further comprising a device-customer exchange module that receives control information for the MVPNs between the source device and one or more customer networks with the routing protocol.

13. The network device of claim 12, wherein the device-customer exchange module receives control information from locally located virtual routing and forwarding (VRF) instances of the source device that correspond to the MVPNs.

14. A system comprising:

a source device within a network;

one or more destination devices within the network, wherein each of the destination devices is coupled to a customer network and belongs to at least one multicast virtual private network (MVPN), and wherein the destination devices receive multicast control messages in the form of join or prune messages from the customer networks; and

a multicast tree established within the network from the source device to the one or more destination devices;

wherein the multicast tree is a point-to-multipoint (P2MP) label switched path (LSP);

wherein the source device and the one or more destination devices exchange routing protocol advertisements that encode the join or prune messages as control information for the MVPNs,

wherein the source device maintains a database for the multicast tree, the database having entries that indicate the MVPNs to which the destination devices belongs based on the join or prune messages received via the routing protocol advertisements.