Virtual circuit management for multi-point delivery in a network system

• US 6,185,210 B1
• Filed: 09/30/1997
• Issued: 02/06/2001
• Est. Priority Date: 09/30/1997
• Status: Expired due to Term

• Current Assignee: Genuity Inc. (Lumen Technologies, Inc.), Raytheon BBN Technologies Corp. (Rtx Corporation), Verizon Corporate Services Group Incorporated (Verizon Communications Inc.)
• Original Assignee: BBN Corporation (Verizon Communications Inc.)
• Inventors: Troxel, Gregory D.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Pizarro, Ricardo M.
• Application Number:
  US08/940,666
• Time in Patent Office: 1,225 Days
• Field of Search: 370/395, 370/397, 370/396, 370/399, 370/400, 370/408, 370/409, 370/410, 370/260, 370/261
• US Class Current: 370/395.32
• CPC Class Codes: H04L 2012/5636 Monitoring or policing, e.g. compliance with allocated rate, corrective actions
• CPC Class Codes: H04L 2012/5642 Multicast/broadcast/point-multipoint, e.g. VOD
• CPC Class Codes: H04L 2012/5667 IP over ATM
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

A system and method for optimizing and managing Qos (Quality of Service) in a network system including a plurality of open point-to-multipoint virtual circuits (VC)s between various endpoint sites, for example in multicast systems. VC optimization includes determining more appropriate set of VC endpoints to reduce oversent data. If below the VC limit, a set of potential VCs is determined, the set excluding combinations with VC connections already open. An estimation or calculation is performed to determined a reduction in oversent data that would occur if that a possible VC was opened. The possible VC with the greatest reduction in oversent data is then opened. Appropriate traffic is moved over to the newly opened VC, and any VCs which no longer have any traffic are closed. If a VC limit is reached for a node, a different optimization technique is used. A set of possible VCs to endpoint sites is determined. From this set, a new VC to open is selected which, if opened, would cause the greatest reduction in oversent data. From the presently opened VCs, an open VC is selected which, if closed, would cause the least increase in oversent data. The new VC is opened, and appropriate traffic and flows are moved to it. The open (old) VC is then closed. These optimization techniques are alternated with other optimization techniques.

Claims

1. In a network system including a plurality of endpoint sites, said network system including a plurality of open point-to-multipoint virtual circuits (VC)s between various endpoint sites, a method of optimizing traffic flow, comprising:

determining a set of possible point-to multipoint VCs to said endpoint sites, said set excluding combinations with VC connections already open;

for each possible VC in said set, estimating a reduction in oversent data that would occur if said possible VC was opened;

opening a new VC corresponding to said possible VC with a greatest reduction in oversent data;

moving appropriate traffic over to the newly opened VC; and

closing any open VCs which no longer have any traffic.

2. The method of claim 1 wherein said step of opening said possible VC further includes:

if said possible VC can not be opened, an identification of said possible VC is placed on a list of VCs which could not be opened.

3. The method of claim 2 wherein said step of determining the set of possible VCs to said endpoint sites further includes excluding VCs identified by said list of VCs which could not be opened.

4. The method of claim 2 wherein said list of VCs which could not be opened is periodically cleared of all entries.

5. The method of claim 1 wherein said method of optimizing traffic flow further includes:

resizing the Qos (quality of service) of an existing open VC.

6. The method of claim 1 wherein if an open VC limit is reached, the steps of:

determining a set of possible VCs to said endpoint sites;

from said set of possible VCs to said endpoint sites, selecting a new VC to open which, if opened, would cause the greatest reduction in oversent data;

from said plurality of open point-to-multipoint VCs, selecting an open VC which, if closed, would cause the least increase in oversent data;

if said new VC is different from said open VC, then opening said new VC;

moving appropriate traffic to said new VC; and

closing said open VC.

7. In a network system including a plurality of endpoint sites, said network system including a plurality of open point-to-multipoint virtual circuits (VC)s between various endpoint sites, a method of optimizing traffic flow, comprising:

determining whether a number of open VCs is at a VC limit;

determining a set of possible VCs to said endpoint sites when the number is at the VC limit;

estimating, for each of the possible VCs, a reduction of oversent data;

from said set of possible VCs to said endpoint sites, selecting a new VC to open based on the estimating;

from said plurality of open point-to-multipoint VCs, selecting an open VC to close;

if said new VC is different from said open VC, then opening said new VC;

moving appropriate traffic to said new VC; and

closing said open VC.

8. The method of claim 7 wherein if said step of selecting the new VC to open from said set of possible VCs to said endpoint sites further includes:

selecting a new VC to open which would cause the greatest reduction in oversent data.

9. The method of claim 8 wherein if said step of selecting an open VC from said plurality of open point-to-multipoint VCs further includes:

selecting an open VC which, if closed, would cause a least increase in oversent data.

10. The method of claim 9 wherein if said step of selecting an open VC which, if closed, would cause the least increase in oversent data includes accounting for said new VC having been opened.

11. The method of claim 7 wherein said step of opening said new VC further includes:

if said new VC can not be opened, an identification of said new VC is placed on a list of VCs which could not be opened.

12. The method of claim 11 wherein said step of determining a set of possible VCs to said endpoint sites further includes excluding VCs identified by said list of VCs which could not be opened.

13. The method of claim 11 wherein said list of VCs which could not be opened is periodically cleared of all entries.

14. A system for controlling traffic flow in a network system, said network system including a plurality of endpoint sites, and including a plurality of open point-to-multipoint virtual circuits (VC)s between various endpoint sites, said system comprising:

an open VC table to hold entries indicating said open VCs, each entry also including an indication of oversent data on each of said open VCs;

a possible VC table to hold entries indicating a set of possible VCs to said endpoint sites;

a network traffic estimator to scan said open VC table and said possible VC table, and to determine, for each entry in said possible VC table, a reduction in oversent data which would occur if a new VC was opened corresponding to that entry;

a VC instantiating component, to open a new VC corresponding to an entry in said possible VC table with a greatest reduction in oversent data; and

a network traffic controller, to move appropriate network traffic to said newly opened VC.

15. The system of claim 14 wherein said network traffic estimator determines said reduction in oversent data which would occur if a new VC was opened corresponding to that entry, by determining what network traffic would be appropriate to send on said new VC.

16. The system of claim 14 wherein said network traffic estimator scans said open VC table to select one of said open VCs to close, and determines a reduction in oversent data for each entry in said possible VC table while presuming said selected open VC is closed.

17. The system of claim 16 further including a VC closing component, to close said selected one of said open VC'"'"'s to close.

18. The system of claim 14 wherein said VC instantiating component includes a failed VC table, to place indications of failed VCs that said VC instantiating component is not able to open.

19. The system of claim 18 wherein said possible VC table excludes entries which correspond to indications of failed VCs in said failed VC table.

20. The system of claim 18 wherein said failed VC table is periodically cleared of said indications of failed VCs.