Network node apparatus and virtual connection control method for providing various service attributes in multicast communication

• US 6,144,661 A
• Filed: 02/04/1997
• Issued: 11/07/2000
• Est. Priority Date: 02/05/1996
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Saito, Takeshi, Katsube, Yasuhiro, Tanaka, Hisako
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): SLAVITT, MITCHELL R
• Application Number:
  US08/794,704
• Time in Patent Office: 1,372 Days
• Field of Search: 370/389, 370/390, 370/395, 370/397, 370/399, 370/475, 370/400, 370/401, 370/396, 370/408, 370/409
• US Class Current: 370/390
• CPC Class Codes: H04L 12/1836 with heterogeneous network architecture
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 2012/563 Signalling, e.g. protocols, reference model
• CPC Class Codes: H04L 2012/5632 Bandwidth allocation
• CPC Class Codes: H04L 2012/5642 Multicast/broadcast/point-multipoint, e.g. VOD
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

A system for forming one point-to-multipoint connection provides various service attributes in an ATM network in response to differences in service attributes requested by receiving parties or differences in available resources. A network node sets up an output VC (Virtual Channel) link to be connected to an input VC link, the VC links being parts of a point-multipoint connection, receives a new VC link set-up request, and adds to the point-multipoint connection, in response to the new VC link set-up request, new output VC link with service attribute different from that of the input VC link.

Claims

1. A network node apparatus for multicast communication service to transmit communication data from a sending party to multiple receiving parties using an input VC (Virtual Channel) and output VCs, the node comprising:

multicast maintenance means for maintaining a point-multipoint connection to be used for the multicast communication service;

reception means for receiving a new VC link creation request for the multicast communication service and a requested service attribute for the new VC link; and

creation means for adding to the point-multipoint connection, in response to the new VC link creation request, a new output VC link, the creation means including

means for examining the requested service attribute, and

means for adding the new output VC link with a service attribute that differs from a service attribute of the input VC link.

2. The network node apparatus according to claim 1, wherein the multicast maintenance means and the creation means reside in the same physical unit.

3. The network node apparatus according to claim 1, wherein the creation means includes

means for adding the new output VC link with the requested service attribute.

4. The network node apparatus according to claim 3, wherein the service attribute requested for said new output VC link includes a best-effort service for which resources are not reserved.

5. The network node apparatus according to claim 1, wherein the creation means comprises

means for determining a resource to satisfy the requested service attribute for said new output VC link;

and

means for allocating the determined resource to said new output VC link.

6. The network node apparatus according to claim 5, wherein the allocating means includes

means for allocating a zero-resource when the requested service attribute for said new output VC link is a best-effort service.

7. The network node apparatus according to claim 5, wherein the allocating means includes

means for allocating a resource smaller than a resource allocated to the input VC link.

8. The network node apparatus according to claim 1, wherein the creation means includes

means for adding said new output VC link with a service attribute identical to the requested service attribute when the service attribute for the input VC link is not less than the requested service attribute.

9. The network node apparatus according to claim 1, wherein the reception means includes

means for receiving the requested service attribute in the new VC link creation request, and

wherein the creation means includes

means for adding said new output VC link with the requested service attribute.

10. The network node apparatus according to claim 1, wherein the reception means includes

means for receiving the requested service attribute in the new VC link creation request, at a datalink layer, and

wherein the creation means includes

means for processing the new VC link creation request at the datalink layer;

and

means, responsive to the processing means, for adding said new output VC link with the requested service attribute.

11. The network node apparatus according to claim 1, wherein the reception means includes

means for receiving a message including the requested service attribute, and

wherein the creation means includes

means for adding said new output VC link with the requested service attribute.

12. The network node apparatus according to claim 1, wherein the reception means includes

means for receiving a message including the requested service attribute at network layer, and

wherein the creation means includes

means for processing the message at the network layer;

and

mean, responsive to the processing means, for adding said new output VC link with the requested service attribute.

13. The network node apparatus according to claim 1, wherein the creation means includes

means for adding said new output VC link with a service attribute different from the requested service attribute when there are not sufficient resources to satisfy the requested service attribute.

14. The network node apparatus according to claim 13, wherein the creation means includes

means for allocating as an insufficient resource a resource that does not exceed an available resource.

15. The network node apparatus according to claim 14, wherein the allocating means includes

means for allocating a zero-resource irrespective of the available resource.

16. The network node apparatus according to claim 14, further comprising,

means for altering the resource allocated to said new output VC link from the insufficient resource to the sufficient resource when the sufficient resource becomes available.

17. The network node apparatus according to claim 16, further comprising,

means for recording that the insufficient resource has been allocated, and

means for checking if the sufficient resource has become available while the recording means records that a sufficient resource could not be allocated;

and

means for activating the altering means, responsive to the checking means.

18. A network node apparatus for multicast communication service to transmit communication data from a sending party to multiple receiving parties using VCs (Virtual Channels), the node comprising:

multicast maintenance means for maintaining a point-multipoint connection for multicast communication service using an input VC link and output VC link;

a memory for storing information indicating a resource allocated to the output VC link;

determining means for determining whether to alter the allocated resource of the output VC link by detecting a change regarding the receiving parties that affects the largest of service attributes to be provided to the receiving parties; and

reallocation means, responsive to the determining means, for allocating a new resource as an altered resource to the output VC link.

19. The network node apparatus according to claim 18, wherein the determining means includes

means for detecting addition of a new receiving party.

20. The network node apparatus according to claim 18, wherein the determining means includes

means for detecting alteration of a service attribute for one of the receiving parties.

21. The network node apparatus according to claim 18, wherein the determining means includes

means for detecting deletion of one of the receiving parties.

22. The network node apparatus according to claim 19, wherein the determining means includes

means for ascertaining the largest of a requested service attribute to be provided to the new receiving party and a service attribute provided to each receiving party ready to receive multicast communication data through the output VC link, and

means for checking whether the ascertained largest resource differs from the resource indicated by the information stored in the memory;

and

wherein the reallocation means includes

means for allocating the ascertained largest resource as the new resource.

23. The network node apparatus according to claim 20, wherein the determining means includes

means for ascertaining the largest of a requested service attribute for the one of the receiving parties for whom the service attribute is to be altered and a service attribute provided to each of the other receiving parties ready to receive multicast communication data through the output VC link, and

means for checking whether the ascertained largest resource differs from the resource indicated by the information stored in the memory;

and

wherein the reallocation means includes

means for allocating the ascertained largest resource as the new resource.

24. The network node apparatus according to claim 21, wherein the determining means includes

means for ascertaining the largest of a service attribute provided to each receiving party ready to receive multicast communication data through the output VC link other than the one of the receiving parties to be deleted, and

means for checking whether the ascertained largest resource differs from the resource indicated by the information stored in the memory;

and

wherein the reallocation means includes

means for allocating the ascertained largest resource as the new resource.

25. The network node apparatus according to claim 18, further comprising

means, responsive to the reallocation means, for entering information indicating the altered resource into the memory.

26. The network node apparatus according to claim 18, further comprising

means for storing in the memory service attribute information identifying a service attribute provided to each receiving party ready to receive multicast communication data through the output VC link;

and

wherein the determining means includes

means for examining the service attribute information to determine whether to alter the resource.

27. The network node apparatus according to claim 26, wherein the storing means includes

means for including information indicating a requested service attribute to be provided to the new receiving party in the service attribute information.

28. The network node apparatus according to claim 26, wherein the means for storing includes

means for including information indicating a requested service attribute to be provided to said one of the receiving parties for whom the service attribute is to be altered in the service attribute information.

29. The network node apparatus according to claim 18, further comprising,

means for receiving a message from a downstream node of the output VC link indicating the largest of the service attributes provided to the receiving parties ready to receive multicast communication data through the output VC link;

and

wherein the determining means includes

means for referring to the message to determine whether to alter the resource.

30. The network node apparatus according to claim 29, further comprising,

means for transmitting to an upstream node of the input VC link a message indicating the largest of the service attributes provided to the receiving parties ready to receive multicast communication data through a plurality of output VC links connected to the input VC link.

31. The network node apparatus according to claim 18, wherein the allocated resource may correspond to best effort service.

32. The network node apparatus according to claim 18, wherein the new resource may correspond to best effort service.

33. A method for controlling a multicast communication service in a connection-oriented network to transmit communication data from a sending party to multiple receiving parties via Virtual Channels (VCs), the method comprising the steps of:

maintaining output VC links to be connected to an input VC link, the VC links being parts of a point-multipoint connection used for the multicast communication service;

receiving a new VC link creation request; and

adding a new output VC link to the point-multipoint connection in response to the receipt of a new VC link creation request, the output VC link having a service attribute that is the smaller of a service attribute of the input VC link and a service attribute requested for said new output VC link.

34. The method according to claim 33, further comprising the step of

increasing a service attribute provided on the input VC link up to the service attribute requested for said new output VC link.

35. The method according to claim 33, wherein the adding step includes the step of

providing on said new output VC link a service attribute different from that of the input VC link when the service attribute of the input VC link exceeds the service attribute requested for said new output VC link.

36. A method for controlling a multicast communication service in a connection-oriented network to transmit communication data from a sending party to multiple receiving parties via Virtual Channels (VCs), the method comprising the steps of:

maintaining output VC links to be connected to an input VC link, the VC links being parts of a point-multipoint connection used for the multicast communication service;

storing information indicating a resource allocated to the output VC link in a memory;

determining a need to alter the resource of the output VC link by detecting a change regarding the receiving parties that affects the largest of service attributes to be provided to the receiving parties; and

reallocating a new resource as an altered resource to the output VC link in response to the determination of a need to alter the resource.

37. A method in accordance with claim 36 wherein the determining step includes the step of

detecting addition of a new receiving party.

38. A method in accordance with claim 36 wherein the determining step includes the step of

detecting alteration of a service attribute for one of the receiving parties.

39. A method in accordance with claim 36 wherein the determining step includes the step of

detecting deletion of one of the receiving parties.

40. A method in accordance with claim 36, wherein the allocated resource may correspond to best effort service.

41. A method in accordance with claim 36, wherein the new resource may correspond to best effort service.

42. A method for controlling a multicast communication service in an ATM network to transmit communication data from a sending party to multiple receiving parties via Virtual Channels (VCs), the method comprising the steps of:

maintaining output VC links to be connected to an input VC link, the VC links being parts of a point-multipoint connection used for the multicast communication service;

receiving a new VC link set-up request;

noting that sufficient resources do not exist to satisfy a service attribute requested for a new output VC link; and

adding to the point-multipoint connection, in response to the receipt of the new VC link set-up request, said new output VC link to which an insufficient resource is allocated.

45. The method according to claim 42, further comprising the steps of,

altering the resource allocated to said new output VC link from the insufficient resource to the sufficient resource when the sufficient resource has become available;

and

requesting alteration of a resource allocated to a downstream output VC link of said new output VC link.

47. The method according to claim 42, wherein the allocated resource may correspond to best effort service.

44. The method according to claim 44, further comprising the step of

reallocating a smaller resource to the input VC link when the resource reserved for the input VC link exceeds the largest of the resources allocated to the output VC links including said new output VC link.

43. The method according to claim 44, wherein the adding step includes the step of

providing a service attribute different from that of the input VC link on said new output VC link when the service attribute of the input VC link is not less than the service attribute requested for said new output VC link.

46. The method according to claim 44, further comprising the step of

altering the resource allocated to said new output VC link from the insufficient resource to the sufficient resource, and the resource reallocated to the input VC link from the smaller resource to the sufficient resource, when the sufficient resource has become available.