Processes, articles, and packets for network path diversity in media over packet applications

• US 6,496,477 B1
• Filed: 04/19/2000
• Issued: 12/17/2002
• Est. Priority Date: 07/09/1999
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Viswanathan, Vishu, Perkins, Stephen J., Anandakumar, Krishanasamy, McCree, Alan V., Gatherer, Alan
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): PHAM, BRENDA H
• Application Number:
  US09/552,090
• Time in Patent Office: 972 Days
• Field of Search: 370/228, 370/230, 370/235, 370/248, 370/356, 370/348, 370/351, 370/360, 370/386, 370/461, 370/428, 370/437, 370/447, 370/462, 370/352, 370/353, 370/354, 370/357, 370/358, 370/364
• US Class Current: 370/228
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 40/20 based on geographic position or location
• CPC Class Codes: H04W 88/182 Network node acting on behalf of an other network entity, e.g. proxy

Abstract

In one form of the invention, a process of sending real-time information from a sender computer to a receiver computer coupled to the sender computer by a packet network wherein packets sometimes become lost, includes steps of directing packets containing the real-time information from the sender computer by at least one path in the packet network to the receiver computer, and directing packets containing information dependent on the real-time information from the sender computer by at least one path deversity path in the packet network to the same receiver computer.

Claims

1. A process of operating a network comprising the steps of:

providing proxies that forward voice over packet communications providing a list server with stored information about the proxies;

executing an identification process that identifies upon request at least two of said proxies for packet network path diversity using the stored information about the proxies.

2. The process of claim 1 wherein said identification process is responsive to a request including a destination area, and includes the steps of selecting the at least two proxies from a prestored list of proxies by geographic region providing path diversity relative to the destination area.

5. The process of claim 1 wherein said identification process is responsive to a request and includes the steps of providing a table of distances between proxies and selecting at least one pair of proxies that are more than a predetermined distance apart.

6. The process of claim 5 wherein the predetermined distance exceeds 200 kilometers.

7. The process of claim 1 wherein said identification process is responsive to a request and includes the steps of providing a table of proxy descriptors relevant to path diversity and selecting at least one pair of proxies that have different descriptors indicative of path diversity.

8. The process of claim 7 wherein the table of proxy descriptors includes class of service information for different proxies.

9. The process of claim 7 wherein the table of proxy descriptors includes geographic information for different proxies.

10. The process of claim 5 wherein the table of proxy descriptors includes location information about different proxies and said selecting step including computing a distance between proxies from the location information.

11. The process of claim 5 wherein the table of proxy descriptors includes service provider information about different proxies.

12. The process of claim 1 wherein said identification process is responsive to a request and includes the steps of providing a table of distances between proxies;

executing a search in the table of distances for one or more acceptable proxy pairs according to a search condition; and

selecting at least one pair of acceptable proxies.

13. The process of claim 12 wherein the search condition provides at least that proxies be more than a predetermined geographic distance apart.

14. The process of claim 12 wherein given a line between a source computer and a destination computer the search condition provides at least that acceptable proxies lie on opposite sides of the line.

15. The process of claim 12 wherein given a line between a source computer and a destination computer, each proxy has a perpendicular distance to the line, and the search condition provides at least that respective distances from acceptable proxies to the line lie in a predetermined zone width but more than a predetermined distance from the line.

16. The process of claim 12 wherein given a line segment between a source computer and a destination computer, the search condition provides at least that acceptable proxies are ones located such that there are respective perpendiculars from the acceptable proxies that intersect the line segment itself.

17. The process of claim 12 wherein the table of distances provides network distances including number of hops between proxies.

18. The process of claim 12 wherein the table of distances provides network distances including a first number of hops between a pair of proxies, and given a second number of hops between one of the proxies and the source, the search condition provides at least that acceptable proxies are ones wherein the first number divided by the second number exceeds a predetermined amount.

19. The process of claim 12 wherein the table of distances provides network distances including numbers of hops from source-to-proxyA, from source-to-proxyB, from proxyA-to-proxyB, from proxyA-to-destination, and from proxyB-to-destination, and the search condition at least provides inequalities on a set of ratios H1, H2, H3, H4 wherein Ratio H1 is a ratio of the number of hops Hab from proxyA-to-proxyB to the number of hops Hsa from source to proxy A, H2 is the ratio of the number of hops Hab from proxyA-to-proxyB to the number of hops Hsb from source to proxy B, H3 is the ratio of the number of hops Hab from proxyA-to-proxyB to the number of hops Had from proxy A to destination, and H4 is the ratio of the number of hops Hab from proxyA-to-proxyB to the number of hops Hbd from proxy B to destination;

and wherein the inequalities are that H1, H2, H3, H4 are respectively greater than respective predetermined constants.

20. The process of claim 12 wherein the table of distances provides network distances including numbers of hops Hsa from source-to-proxyA, Hsb from source-to-proxyB, Had from proxyA-to-destination, and Hbd from proxyB-to-destination, and the search includes a search in a range of values of a path-length ratio H0=(Hsa+Had)/(Hsb+Hbd).

21. The process of claim 12 wherein the table of distances includes network distances as a matrix of entries to indicate presence or absence of a network link between a given pair of network nodes free of any intermediate network node between the given pair.

22. The process of claim 21 wherein given a source and a destination, the process includes searching the matrix of entries for different network paths between the source and destination.

23. The process of claim 22 wherein at least one pair of paths are selected depending on a search condition depending on number of path nodes in common.

24. The process of claim 22 wherein at least one pair of paths are selected which has a ratio of a first number of path nodes in common divided by a sum of the nodes in each path wherein the ratio is less than a predetermined amount.

25. The process of claim 12 wherein given a source and a destination, the process includes searching the table of distances for different network paths between the source and destination.

26. The process of claim 25 wherein at least one pair of paths are selected based on a first number depending on links shared by the paths divided by a second number depending on the number of links in at least one of the paths.

27. The process of claim 25 wherein at least one pair of paths are selected by comparing numbers of links in the paths of the pair.

3. The process of claim wherein said identification process is responsive to a request including a destination area, and includes the steps of responding with proxy identifiers for a first one of the at least two proxies from a first prestored list of proxies in a first geographic region and responding with proxy identifiers for a second one of the at least two proxies from a second prestored list of proxies in a second geographic region.

4. The process of claim wherein said identification process is responsive to a request and includes the steps of

providing a prestored region table that identifies the proxies located in respective regions;

identifying first region in which a source computer lies, and a second region in a destination computer lies;

from the source and destination regions thus identified, then identifying third and fourth regions other than the first and second regions, wherein the third and fourth regions are displaced from a line joining the source and destination regions;

accessing the region table for the third region and providing at least one identifier of a proxy in the third region; and

accessing the region table for the fourth region and providing at least one identifier of a proxy in the fourth region.