Separation of edge and routing/control information for multicast over shortest path bridging
View Patent ↗Techniques disclosed herein include systems and methods for providing a scalable solution to transmit edge IP Multicast sender information in a Shortest Path Bridging (SPB) network. Control information is exchanged between Ingress Backbone Edge Bridges and Egress Backbone Edge Bridges Such control messages do not cause path computations at Backbone Core Bridges within the SPB network. Such exchanges of control messages trigger sending SPB specific Intermediate System To Intermediate System (IS-IS) TLV control message with path computation information via IS-IS control messages. This second set of control messages is exchanged within the SPB network and includes source-specific multicast stream information that is used by Backbone Core Bridges to establish a multicast forward state and compute multicast forwarding paths. By separating edge and routing information, IP multicasting functionality within the SPB is provided while enabling scaling and new edge multicasting applications.
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 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 first control message indicating that the second data switching device is a transmitter node for a multicast data stream, the multicast data stream identified using an Internet Protocol (IP) Source Address, an IP Destination Address, a Virtual Local Area Network identifier, and a Data Service Instance Identifier (Data I-SID);
in response to identifying that the first data switching device is a receiver node for the Data I-SID, generating a second control message indicating that the first data switching device is a receiver node for the multicast data stream identified using both the Data I-SID and a nickname of the second data switching device, the second control message being a different type of control message as compared to the first control message, the second control message structured such that a Backbone Core Bridge within the transport network uses the second control message for computing a multicast path within the transport network;
transmitting the second control message to the second data switching device via the transport network; and
receiving, at the first data switching device, data packets corresponding to the multicast data stream; and
updating a link state database used by the first data switching device such that the link state database indicates that the second data switching device is the transmitter node for the Data I-SID; and
building a forwarding table used by the first data switching device including refraining from creating forwarding entries for Data I-SIDs that are not linked to a specific nickname of a given data switching device.
2. The computer-implemented method of claim 1 , wherein the first control message is structured such that the Backbone Core Bridge within the transport network forwards the first control message without using the first control message for computing the multicast path within the transport network.
3. The computer-implemented method of claim 2 , wherein the first control message is an Intermediate System To Intermediate System (IS-IS) Layer 2 control message having a first type-length-value (TLV) structure.
4. The computer-implemented method of claim 3 , wherein the first control message is a Multicast Flow Specific TLV.
5. The computer-implemented method of claim 2 , wherein the first control message is a Border Gateway Protocol control message.
6. The computer-implemented method of claim 1 , wherein the first control message and second control messages are both Intermediate System To Intermediate System (IS-IS) type-length-value (TLV) control messages that have different TLV structures compared to each other.
7. The computer-implemented method of claim 1 , further comprising:
receiving a third control message at the first data switching device, the third control message originating from a second data switching device, the third control message indicating that the second data switching device is a transmitter node for the multicast data stream identified using the Data I-SID, the third control message being a same type of control message as compared to the second control message, the third control message structured such that the Backbone Core Bridge within the transport network uses the third control message for computing the multicast path within the transport network.
8. 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 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 first control message indicating that the second data switching device is a transmitter node for a multicast data stream, the multicast data stream identified using an Internet Protocol (IP) Source Address, an IP Destination Address, a Virtual Local Area Network identifier, and a Data Service Instance Identifier (Data I-SID);
in response to identifying that the first data switching device is a receiver node for the Data I-SID, generating a second control message indicating that the first data switching device is a receiver node for the multicast data stream identified using both the Data I-SID and a nickname of the second data switching device, the second control message being a different type of control message as compared to the first control message, the second control message structured such that a Backbone Core Bridge within the transport network uses the second control message for computing a multicast path within the transport network;
transmitting the second control message to the second data switching device via the transport network; and
receiving, at the first data switching device, data packets corresponding to the multicast data stream; and
updating a link state database used by the first data switching device such that the link state database indicates that the second data switching device is the transmitter node for the Data I-SID; and
building a forwarding table used by the first data switching device including refraining from creating forwarding entries for Data I-SIDs that are not linked to a specific nickname of a given data switching device.
9. The system of claim 8 , wherein the first control message is structured such that the Backbone Core Bridge within the transport network forwards the first control message
without using the first control message for computing the multicast path within the transport network.
10. The system of claim 9 , wherein the first control message is an Intermediate System To Intermediate System (IS-IS) Layer 2 control message having a first type-length-value (TLV) structure.
11. The system of claim 9 , wherein the first control message is a Border Gateway Protocol control message.
12. The system of claim 8 , wherein the first control message and second control messages are both Intermediate System To Intermediate System (IS-IS) type-length-value (TLV) control messages that have different TLV structures compared to each other.
13. The system of claim 8 , wherein the memory stores further instructions that, when executed by the processor, cause the system to perform the operations of:
receiving a third control message at the first data switching device, the third control message originating from a second data switching device, the third control message indicating that the second data switching device is a transmitter node for the multicast data stream identified using the Data I-SID, the third control message being a same type of control message as compared to the second control message, the third control message structured such that the Backbone Core Bridge within the transport network uses the third control message for computing the multicast path within the transport network.
14. A computer-implemented method for packet switching in a Shortest Path Bridging (SPB) network, the computer-implemented method comprising:
receiving, at a first data switching device, a multicast data stream to transmit via a transport network using Shortest Path Bridging (SPB) protocol, the first data switching device functioning as a first Backbone Edge Bridge within the transport network, the multicast data stream being an Internet Protocol (IP) multicast data stream having a source and group identification and received from an access network that is logically distinct from the SPB network;
dynamically allocating a Data Service Instance Identifier (Data I-SID) that identifies the multicast data stream within the SPB network;
sending a first control message to Backbone Edge Bridges within the transport network, the first control message indicating that the first data switching device is a transmitter node for the multicast data stream, the multicast data stream identified using an IP Source Address, an IP Destination Address, a Virtual Local Area Network identifier, and the Data I-SID;
sending a second control message to Backbone Edge Bridges within the transport network, the second control message indicating that the first data switching device is the transmitter node for the multicast data stream identified using the Data I-SID, the second control message being a different type of control message as compared to the first control message, the second control message structured such that a Backbone Core Bridge within the transport network uses the second control message for computing a multicast path within the transport network;
receiving, at the first data switching device, a third 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 third control message indicating that the second data switching device is a receiver node for the multicast data stream identified using both the Data I-SID and a nickname of the first data switching device, the third control message structured such the Backbone Core Bridge within the transport network use the Data I-SID and nickname of the first data switching device to compute the multicast data path; and
forwarding data packets to the second data switching device via the transport network, the data packets indicating the I-SID and indicating the first data switching device as the transmitter node; and
updating a link state database used by the first data switching device such that the link state database indicates that the second data switching device is the transmitter node for the Data I-SID; and
building a forwarding table used by the first data switching device including refraining from creating forwarding entries for Data I-SIDS that are not linked to a specific nickname of a given data switching device.
15. The computer-implemented method of claim 14 , wherein the first control message is structured such that the Backbone Core Bridge within the transport network forwards the first control message without using the first control message for computing the multicast path within the transport network.
16. The computer-implemented method of claim 15 , wherein the first control message is an Intermediate System To Intermediate System (IS-IS) Layer 2 control message having a first type-length-value (TLV) structure.
17. The computer-implemented method of claim 15 , wherein the first control message is a Border Gateway Protocol control message.
18. The computer-implemented method of claim 14 , further comprising:
updating the forwarding table used by the first data switching device such that data packets indicating the Data I-SID and also indicating the second data switching device as the receiver node are routed to the second data switching device.