Method to route multicast data in SPB network by establishing the virtual PIM adjacency across the SPB networks in a single PIM domain
View Patent ↗Techniques disclosed herein include systems and methods that extend Protocol Independent Multicast (PIM) protocols to Shortest Path Bridging (SPB) technology. This includes connecting an IP multicast domain across an SPB network. SPB edge routers, also known as Backbone Edge Bridges, form virtual adjacencies with each other. As such, SPB edge routers maintain such PIM adjacency without sending Hello messages. Backbone Edge Bridges (BEBs) are discovered using null Intermediate System To Intermediate System (IS-IS) Internet Protocol Multicast (IPMC) type-length-value (TLV) control messages. Each PIM-enabled BEB records other PIM-enabled BEBs as an adjacent PIM-router in response to receiving a NULL IPMC TLV from those BEBs. Accordingly, PIM-enabled BEBs form a full mesh virtual adjacency between each other and can thereby encapsulate PIM control messages sent and received between two access networks connected to the SPB network.
1. A computer-implemented method for packet switching in a Shortest Path Bridging (SPB) network, the computer-implemented method comprising:
receiving a first control message at a first data switching device, the first data switching device functioning as a first Backbone Edge Bridge within a transport network using Shortest Path Bridging protocol, the first data switching device also functioning as a first Protocol Independent Multicast (PIM) router, the first data switching device connected to a first access network, the first control message originating from a second data switching device, the second data switching device functioning as a second Backbone Edge Bridge within the transport network, the second data switching device connected to a second access network;
in response to interpreting the first control message as signaling that the second data switching device is also functioning as a second PIM router, adding the second data switching device to a record that indicates Backbone Edge Bridges within the transport network having PIM adjacency with the first data switching device;
receiving a PIM Join control message at the first data switching device from the first access network; and
encapsulating the PIM Join control message using Mac-in-Mac encapsulation and transmitting the PIM Join control message towards a PIM rendezvous point RP via the transport network.
2. The computer-implemented method of claim 1 , wherein interpreting the first control message as signaling that the second data switching device is also functioning as a second PIM router is in response to identifying that the first control message is an Intermediate System To Intermediate System (IS-IS) control message having a null type-length-value (TLV).
3. The computer-implemented method of claim 2 , wherein the TLV indicates a TLV type as IS-IS Internet Protocol Multicast TLV control message.
4. The computer-implemented method of claim 1 , wherein adding the second data switching device to a record that indicates Backbone Edge Bridges within the transport network having PIM adjacency with the first data switching device includes maintaining the Backbone Edge Bridges in the record as adjacent PIM routers without receiving PIM Hello messages.
5. The computer-implemented method of claim 1 , wherein receiving the first control message from the second data switching device includes the second data switching device being two or more hops away from the first data switching device in the transport network.
6. The computer-implemented method of claim 1 , wherein the second data switching device connected to a second access network includes the second access network belonging to a same Internet Protocol multicast domain as the first access network.
7. The computer-implemented method of claim 1 , further comprising:
generating a second control message signaling that the first data switching device is the first PIM router; and
transmitting the second control message to Backbone Edge Bridges within the transport network.
8. The computer-implemented method of claim 7 , wherein generating the second control message includes generating a null Intermediate System To Intermediate System (IS-IS) type-length-value (TLV) control message.
9. A computer program product including a non-transitory computer-storage medium having instructions stored thereon for processing data information, such that the instructions, when carried out by a processing device, cause the processing device to perform the operations of:
receiving a first control message at a first data switching device, the first data switching device functioning as a first Backbone Edge Bridge within a transport network using Shortest Path Bridging protocol, the first data switching device also functioning as a first Protocol Independent Multicast (PIM) router, the first data switching device connected to a first access network, the first control message originating from a second data switching device, the second data switching device functioning as a second Backbone Edge Bridge within the transport network, the second data switching device connected to a second access network;
in response to interpreting the first control message as signaling that the second data switching device is also functioning as a second PIM router, adding the second data switching device to a record that indicates Backbone Edge Bridges within the transport network having PIM adjacency with the first data switching device;
receiving a PIM Join control message at the first data switching device from the first access network; and
encapsulating the PIM Join control message using Mac-in-Mac encapsulation and transmitting the PIM Join control message towards a PIM rendezvous point RP via the transport network.
10. The computer program product of claim 9 , wherein interpreting the first control message as signaling that the second data switching device is also functioning as a second PIM router is in response to identifying that the first control message is an Intermediate System To Intermediate System (IS-IS) control message having a null type-length-value (TLV).
11. The computer program product of claim 10 , wherein the TLV indicates a TLV type as IS-IS Internet Protocol Multicast TLV control message.
12. The computer program product of claim 9 , wherein adding the second data switching device to a record that indicates Backbone Edge Bridges within the transport network having PIM adjacency with the first data switching device includes maintaining the Backbone Edge Bridges in the record as adjacent PIM routers without receiving PIM Hello messages.
13. The computer program product of claim 9 , wherein receiving the first control message from the second data switching device includes the second data switching device being two or more hops away from the first data switching device in the transport network.
14. The computer program product of claim 9 , wherein the second data switching device connected to a second access network includes the second access network belonging to a same Internet Protocol multicast domain as the first access network.
15. The computer program product of claim 9 , having further instructions stored thereon for processing data information, such that the further instructions, when carried out by the processing device, cause the processing device to perform the operations of:
generating a second control message signaling that the first data switching device is the first PIM router; and
transmitting the second control message to Backbone Edge Bridges within the transport network.
16. The computer program product of claim 15 , wherein generating the second control message includes generating a null Intermediate System To Intermediate System (IS-IS) type-length-value (TLV) control message.
17. A system for packet switching in a Shortest Path Bridging (SPB) network, the system comprising:
a processor; and
a memory coupled to the processor, the memory storing instructions that, when executed by the processor, cause the system to perform the operations of:
receiving a first control message at a first data switching device, the first data switching device functioning as a first Backbone Edge Bridge within a transport network using Shortest Path Bridging protocol, the first data switching device also functioning as a first Protocol Independent Multicast (PIM) router, the first data switching device connected to a first access network, the first control message originating from a second data switching device, the second data switching device functioning as a second Backbone Edge Bridge within the transport network, the second data switching device connected to a second access network;
in response to interpreting the first control message as signaling that the second data switching device is also functioning as a second PIM router, adding the second data switching device to a record that indicates Backbone Edge Bridges within the transport network having PIM adjacency with the first data switching device;
receiving a PIM Join control message at the first data switching device from the first access network; and
encapsulating the PIM Join control message using Mac-in-Mac encapsulation and transmitting the PIM Join control message towards a PIM rendezvous point RP via the transport network.
18. The system of claim 17 , wherein interpreting the first control message as signaling that the second data switching device is also functioning as a second PIM router is in response to identifying that the first control message is an Intermediate System To Intermediate System (IS-IS) control message having a null type-length-value (TLV); and wherein adding the second data switching device to a record that indicates Backbone Edge Bridges within the transport network having PIM adjacency with the first data switching device includes maintaining the Backbone Edge Bridges in the record as adjacent PIM routers without receiving PIM Hello messages.
19. The system of claim 18 , wherein receiving the first control message from the second data switching device includes the second data switching device being two or more hops away from the first data switching device in the transport network. access network.
20. The system of claim 17 , the memory storing further instructions that, when executed by the processor, cause the system to perform the operations of:
generating a second control message signaling that the first data switching device is the first PIM router;
transmitting the second control message to Backbone Edge Bridges within the transport network; and
wherein generating the second control message includes generating a null Intermediate System To Intermediate System (IS-IS) type-length-value (TLV) control message.