Method and system for provisioning network resources for dynamic multicast groups

• US 6,556,544 B1
• Filed: 10/22/1999
• Issued: 04/29/2003
• Est. Priority Date: 10/22/1999
• Status: Expired due to Term

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Lee, Cheng Y.
• Primary Examiner(s): Vincent, David
• Assistant Examiner(s): Duong, Frank
• Application Number:
  US09/422,646
• Time in Patent Office: 1,285 Days
• Field of Search: 370/389, 370/390, 370/392, 370/393, 370/400, 370/401, 370/432, 370/408, 370/469, 370/475, 370/230, 370/235, 370/237, 370/238, 370/255, 370/256
• US Class Current: 370/256
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/185 with management of multicast group membership

Abstract

A system for provisioning a dynamic multicast group over a differentiated services (DS) network includes an a plurality of edge nodes, each of which includes a respective multicast traffic engineering entity. An ingress node is adapted to serve as a source of data traffic of the dynamic multicast group. An egress node is adapted to serve as a sink of the data traffic of the dynamic multicast group. The multicast traffic engineering entity of the egress node is adapted for receiving information respecting a predetermined service level specification (SLS) of the dynamic multicast group; and provisioning a distribution path from the egress node back to the ingress node, on the basis of the received information respecting the SLS. In a method of the invention, information respecting a predetermined service level specification (SLS) of the dynamic multicast group is received at the egress node; and the distribution path is provisioned from the egress node back to the ingress node, on the basis of the received information respecting the SLS. The advantage is reliable automated provisioning of dynamic multicast trees in differentiated service networks.

Claims

1. A method of provisioning a distribution path of a multicast tree from an egress node in a dynamic multicast group in a differentiated services (DS) network, the method comprising the steps of:

a) receiving information respecting a predetermined service level specification (SLS) for the dynamic multicast group at the egress node; and

b) provisioning the distribution path from the egress node toward a root of the multicast tree, on the basis of the received information respecting the SLS.

2. A method as claimed in claim 1, wherein the information respecting the SLS is a resource requirement for the distribution path.

3. A method as claimed in claim 1, wherein the step of receiving information respecting the SLS comprises a step of receiving, at the egress node, a message including the information respecting the SLS.

4. A method as claimed in claim 3, further comprising the steps of:

a) receiving a query message from the egress node; and

b) subsequently sending a response to the query message, the response including the information respecting the SLS.

5. A method as claimed in claim 4, wherein the query message is received at one or more of an ingress node and an SLS database server.

6. A method as claimed in claim 1, wherein the step of provisioning a distribution path comprises a step of provisioning each hop of the path, in sequence, starting from the egress node and progressing toward the root of the multicast tree.

7. A method as claimed in claim 6, wherein the step of provisioning each hop of the path comprises the steps of:

a) forwarding a graft message toward the root of the multicast tree;

b) receiving the graft message at a network element intermediate an ingress node and the egress node; and

c) allocating resources of the network element to the distribution path.

8. A method as claimed in claim 7, further comprising a step of setting a forwarding state of the network element to thereby enable forwarding of multicast traffic toward the egress node.

9. A method as claimed in claim 7, wherein the graft message is forwarded from the egress node toward the root of the multicast tree along a route traversed by the distribution path as its is provisioned.

10. A method as claimed in claim 9, wherein the route is determined in accordance with any one or more of:

a) a shortest path route between the egress node and the ingress node;

b) a constraint based routing (CBR) table including predetermined path routing information defined by a network provider;

c) an explicit routing object (ERO) including predetermined path routing information defined by a network provider; and

d) a path discovery algorithm.

11. A method as claimed in claim 10, wherein information respecting the route is determined by the egress node and included in the graft message.

12. A method as claimed in claim 7, further comprising, when the network element is carrying multicast traffic of the multicast group, the steps of:

a) setting a forwarding state of the network element to enable forwarding of the multicast traffic to the egress node; and

b) terminating the graft message.

13. A method as claimed in claim 1, further comprising, when a second ingress node joins the dynamic multicast group, the steps of:

a) obtaining information respecting the predetermined service level specification (SLS) for the dynamic multicast group; and

b) re-provisioning the distribution path, from the second ingress node toward each egress node of the dynamic multicast group, on the basis of the received information respecting the SLS.

14. A method as claimed in claim 13, wherein the step of obtaining information respecting the SLS comprises a step of sending a query message to one or more of a first ingress node and an SLS database server.

15. A method as claimed in claim 13, wherein the step of re-provisioning the distribution path comprises allocating additional resources to each path segment forming the distribution path between the second ingress node and a respective egress node.

16. An edge node for receiving a multicast traffic of a dynamic multicast group transmitted over a differentiated services (DS) network from an ingress node, the edge node comprising a multicast traffic engineering (MCTE) entity adapted for:

a) receiving information respecting a predetermined service level specification (SLS) of the dynamic multicast group; and

b) provisioning a distribution path from the edge node back to the ingress node, on the basis of the received information respecting the SLS.

17. An edge node as claimed in claim 16, further comprising:

a) a path selection entity adapted to select a route along which the distribution path is provisioned; and

b) a traffic configuration table adapted for storing information respecting the selected route.

18. An edge node as claimed in claim 16, wherein the MCTE entity is adapted to receive a message including the information respecting the SLS.

19. An edge node as claimed in claim 16, wherein the MCTE entity is adapted to send a query message requesting the information respecting the SLS.

20. An edge node as claimed in claim 19, wherein the MCTE entity is adapted to send the query message to any one or more of the ingress node and an SLS database server.

21. An edge node as claimed in claim 16, wherein the MCTE entity is adapted to forward a graft message toward a root of the multicast tree.

22. An edge node as claimed in claim 21, wherein the MCTE entity is adapted to forward the graft message toward the root of the multicast tree along a route traversed by the distribution path as its is provisioned.

23. An edge node as claimed in claim 22, wherein the path selection entity is adapted to determine the route in accordance with any one or more of:

a) a shortest path route between the egress node and the ingress node;

b) a constraint based routing (CBR) table including predetermined path routing information defined by a network provider;

c) an explicit routing object (ERO) including predetermined path routing information defined by a network provider; and

d) a path discovery algorithm.

24. An edge node as claimed in claim 23, wherein the MCTE entity is adapted to include information respecting the route in the graft message.

25. A system for provisioning a distribution path of a dynamic multicast group over a differentiated services (DS) network, the system comprising:

a) an ingress node adapted to serve as a source of data for the dynamic multicast group; and

b) an egress node adapted to serve as a sink for the data of the dynamic multicast group, the egress node comprising a multicast traffic engineering (MCTE) entity adapted to;

i) receive information respecting a predetermined service level specification (SLS) of the dynamic multicast group; and

ii) provision a distribution path from the egress node back to the ingress node, on the basis of the received information respecting the SLS.

26. A system as claimed in claim 25, wherein the information respecting the SLS is a resource requirement for the distribution path.

27. A system as claimed in claim 25, wherein the MCTE entity is adapted for receiving a message including the information respecting the SLS.

28. A system as claimed in claim 27, wherein the ingress node comprises:

a) means for receiving a query message from the egress node; and

b) means for sending a response to the message, the response including the information respecting the SLS.

29. A system as claimed in claim 25, wherein the MCTE entity is adapted for provisioning each hop of the path, in sequence, starting from the egress node and progressing toward the ingress node.

30. A system as claimed in claim 29, wherein the MCTE entity is adapted for forwarding a graft message toward a root of the multicast tree.

31. A system as claimed in claim 30, further comprising a network element intermediate the ingress node and the egress node, the network element comprising a respective traffic engineering (TE) entity adapted to;

a) receive the graft message; and

b) allocate resources of the network element to the distribution path in accordance with information included in the graft message.

32. A system as claimed in claim 31, wherein the MCTE entity is further adapted to set a forwarding state of the network element to thereby enable forwarding of multicast traffic toward the egress node.

33. A system as claimed in claim 31, wherein the MCTE entity of the egress node and the TE entity of the network element are adapted to forward the graft message toward the root of the multicast tree along a route traversed by the distribution path as its is provisioned.

34. A system as claimed in claim 33, wherein the egress node further comprises a path selection entity adapted to select the route in accordance with any one or more of:

a) a shortest path route between the egress node and the ingress node;

b) a constraint based routing (CBR) table including predetermined path routing information defined by a network provider;

c) an explicit routing object (ERO) including predetermined path routing information defined by a network provider; and

d) a path discovery algorithm.

35. A system as claimed in claim 34, wherein the MCTE entity of the egress node is adapted to include information of the route in the graft message.

36. A system as claimed in claim 31, wherein, when the network element is carrying multicast traffic of the multicast group, the TE entity of the network element is further adapted to:

a) set a forwarding state of the network element to enable forwarding of the multicast traffic to the egress node; and

b) terminate the graft message.