Multiple network configuration with local and remote network redundancy by dual media redirect

• US 6,324,161 B1
• Filed: 04/30/1998
• Issued: 11/27/2001
• Est. Priority Date: 08/27/1997
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel USA Sourcing L.P. (Nokia Corporation)
• Inventors: Kirch, Tony M.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): Tsegaye, Saba
• Application Number:
  US09/070,581
• Time in Patent Office: 1,307 Days
• Field of Search: 370/352, 370/353, 370/354, 370/389, 370/401, 370/216, 370/217, 370/218, 370/225, 370/228, 709/238, 709/239, 709/249, 709/250
• US Class Current: 370/217
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities
• 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 45/28 using route fault recovery
• 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

Abstract

A communications configuration comprising a first network medium having a first IP address and a second network having a second IP address. The configuration further includes a first host station with a first interface connected to communicate with the first network medium using the first IP address and a second interface connected to communicate with the second network medium using the second IP address. The configuration further includes a third network medium having a third IP address and a fourth network having a fourth IP address. Still further, the configuration includes a first router station coupled between the first network medium and the third network medium and a second router station coupled between the second network medium and the fourth network medium. Lastly, the configuration includes a second host station. The second host station includes a first interface connected to communicate with the third network medium using the third IP address and a second interface connected to communicate with the fourth network medium using the fourth IP address. The memory of the second host station is programmed to perform various steps. A first step detects a communications failure along a first communication path including the first interface of the first host station, the first network medium, the first router station, the third network medium, and the first interface of the second host station. A second step, responsive to the detected failure, redirects communications addressed to pass along a second communication path from the second host station to the first host station such that redirected communications are not attempted by the second host station to the first host station along the first communication path.

Claims

1. A communications configuration, comprising:

a first network medium having a first IP address;

a second network medium having a second IP address;

a first host station, comprising;

a first interface connected to communicate with the first network medium using the first IP address;

a second interface connected to communicate with the second network medium using the second IP address;

a third network medium having a third IP address;

a fourth network medium having a fourth IP address;

at least a first router station coupled between the first network medium and the third network medium;

at least a second router station coupled between the second network medium and the fourth network medium; and

a second host station, comprising;

a first interface connected to communicate with the third network medium using the third IP address;

a second interface connected to communicate with the fourth network medium using the fourth IP address; and

memory programmed to perform the steps of;

detecting a communications failure along a first communication path including the first interface of the first host station, the first network medium, the first router station, the third network medium, and the first interface of the second host station; and

responsive to the detected failure, redirecting communications addressed to pass from the second host station to the first host station to pass along a second communication path from the second host station to the first host station such that redirected communications are not attempted by the second host station to the first host station along the first communication path.

2. The communications configuration of claim 1 wherein the second communication path comprises the second interface of the second host station, the fourth network medium, the second router station, and the second interface of the first host station.

3. The communications configuration of claim 2 wherein the memory is further programmed to perform the steps of:

detecting a communications failure along the second communication path; and

responsive to the detected failure along the second communication path, and having not detected a communications failure along the first communication path, redirecting communications addressed to pass from the second host station to the first host station along the first communication path.

4. The communications configuration of claim 1:

wherein the second host station is remote from the first network medium and the second network medium in that the second host station consists of a plurality of interfaces for communicating to corresponding network media;

wherein the plurality of interfaces include the first interface connected to communicate with the third network medium and the second interface connected to communicate with the fourth network medium; and

wherein none of the plurality of interfaces has a network address equal to either the first IP address or the second IP address.

5. The communications configuration of claim 1 wherein the redirecting step is responsive to a route table accessible by the memory.

6. The communications configuration of claim 5:

wherein the route table comprises a plurality of remote host route entries; and

wherein each of the plurality of remote host route entries comprises;

an IP address of a remote host station; and

an identifier of a router station coupled to communicate with the remote host station.

7. The communications configuration of claim 1 wherein the first host station further comprises a memory programmed to read a file comprising a plurality of remote network identifiers.

8. The communications configuration of claim 7:

wherein the file further comprises a plurality of router station identifiers corresponding to the plurality of remote network identifiers; and

wherein each of the plurality of router station identifiers identifies a router station directly connected to the first host station and through which a communication may be passed to a remote network identified by the corresponding one of the plurality of the remote network identifiers.

9. The communications configuration of claim 8 wherein the first host station further comprises a memory programmed to perform the step of periodically transmitting a heartbeat packet to each remote network identified by a corresponding remote network identifier in the file.

10. The communications configuration of claim 9:

wherein the memory of the second host station is further comprised to perform the step of monitoring receipt of each heartbeat packet from the first host station; and

wherein the step of redirecting communications by the second host station is responsive to detecting a failure to receive a heartbeat packet from the first host station within a timeout interval.

11. The communications configuration of claim 10 wherein the step of monitoring receipt of each heartbeat packet from the first host station comprises:

forming an internal timing table accessible by the second host station;

responsive to receipt of a heartbeat packet, updating an entry in the internal timing table by entering a time stamp representative of a time when the heartbeat packet is received by the second host station.

12. The communications configuration of claim 11 wherein the step of detecting a failure to receive a heartbeat packet from the first host station comprises calculating a time difference by comparing a present time to the time stamp and determining that the time difference exceeds the timeout interval.

13. The communications configuration of claim 1:

wherein the memory of the second host station is further programmed to execute one or more applications programs; and

wherein the detecting and redirecting steps are transparent to the one or more applications programs.

14. The communications configuration of claim 1 wherein each of the first, second, third, and fourth network media is an Ethernet medium.

15. The communications configuration of claim 1 wherein the first station further comprises a memory programmed to perform the steps of:

detecting a communications failure along a third communication path including the first interface of the second host station, the third network medium, the first router station, the first network medium, and the first interface of the first host station; and

responsive to the detected failure along the third communication path, redirecting communications addressed to pass from the first host station to the second host station to pass along a fourth communication path from the first host station to the second host station such that redirected communications are not attempted by the first host station to the second host station along the third communication path.

16. The communications configuration of claim 1:

and further comprising;

a plurality of local network media including the first and second network media;

a plurality of remote network media including the third and fourth network media;

a plurality of router stations including the first and second router stations, wherein each of the plurality of router stations is coupled between one of the plurality of local network media and a corresponding one of the plurality of remote network media; and

wherein the first host station further comprises;

a plurality of interfaces including the first and second interface, wherein each of the plurality of interfaces is connected to communicate with a respective one of the plurality of local network media and using a respective IP address; and

a memory programmed to perform the steps of;

detecting a communications failure along a first remote communication path including a first one of the plurality of router stations, the respective one of the plurality of remote network media to which the first one of the plurality of router stations is coupled, and a first interface of a remote destination host station coupled to communicate with the respective one of the plurality of remote network media; and

responsive to the detected failure along the first remote communication path, redirecting communications from the first host station to the remote destination host station along a second remote communication path such that redirected communications are not attempted by the first host station along the first remote communication path, wherein the second remote communication path includes a second one of the plurality of router stations, the respective one of the plurality of remote network media to which the second one of the plurality of router stations is coupled, and the second interface of the remote destination host station.

17. The communications configuration of claim 1 wherein the memory of the second host station is further programmed to perform the steps of:

detecting a re-established communication along the first communication path after the step of detecting the failure; and

responsive to the re-established communication, permitting communications from the second host station to the first host station to occur along the first communication path.

18. A communications configuration, comprising:

a plurality of local network media;

a plurality of local host stations, each comprising;

a first interface connected to communicate with at least one of the plurality of local network media using an IP address corresponding to the at least one of the plurality of local network media; and

a second interface connected to communicate with another of the plurality of local network media using an IP address corresponding to the another of the plurality of local network media; and

a plurality of remote network media;

a plurality of remote host stations, each comprising;

a first interface connected to communicate with at least one of the plurality of remote media using an IP address corresponding to the at least one of the plurality of remote network media;

a second interface connected to communicate with another of the plurality of remote media using an IP address corresponding to the another of the plurality of remote network media;

a plurality of router stations, wherein each of the plurality of router stations is coupled between one of the plurality of local network media and a corresponding one of the plurality of remote network media; and

wherein at least one the plurality of local host stations further comprises a memory programmed to perform the steps of;

detecting a communications failure along a first remote communication path including a first one of the plurality of router stations, the respective one of the plurality of remote network media to which the first one of the plurality of router stations is coupled, and a first interface of one of the plurality of remote host stations coupled to communicate with the respective one of the plurality of remote network media; and

responsive to the detected failure along the first remote communication path, redirecting communications from the at least one of the plurality of local host stations to the one of the plurality of remote host stations along a second remote communication path such that redirected communications are not attempted by the at least one of the plurality of local host stations along the first remote communication path.

19. The communications configuration of claim 18 wherein the second remote communication path includes a second of the plurality of router stations, the respective one of the plurality of remote network media to which the second of the plurality of router stations is coupled, and a second interface of the one of the plurality of remote host stations.

20. A first host station, comprising:

a first interface for connecting to a first network medium;

a second interface for connecting to a second network medium;

wherein the first network medium is further coupled through a first router station to communicate with a third network medium, and wherein the third network medium is further coupled to communicate with a second host station via a first interface of the second host station connected to the third network medium; and

memory programmed to perform the steps of;

detecting a communications failure along a first communication path including the first interface of the first host station, the first network medium, the first router station, the third network medium, and the first interface of the second host station; and

responsive to the detected failure, redirecting communications addressed to pass from the first host station to the second host station to pass along a second communication path from the first host station to the second host station such that redirected communications are not attempted by the first host station to the second host station along the first communication path.

21. The first host station of claim 20 wherein the redirecting step comprises communicating communications along the second communication path comprising a path through a second interface of the first host station to the second network medium, from the second network medium through a second router station to a fourth network medium, and from the fourth network medium to a second interface of the second host station.

22. The first host station of claim 20 wherein the redirecting step is responsive to a route table accessible by the memory.

23. The first host station of claim 20:

wherein the memory is further programmed to monitor receipt of periodic heartbeat packets from the second host station; and

wherein the step of redirecting communications by the first host station is responsive to detecting a failure to receive a heartbeat packet from the second host station within a timeout interval.

24. The first host station of claim 23 wherein the memory is further programmed to perform the steps of:

forming an internal timing table accessible by the first host station; and

responsive to receipt of a heartbeat packet, updating an entry in the internal timing table by entering a time stamp representative of a time when the heartbeat packet is received by the first host station.

25. The first host station of claim 24 wherein the step of detecting a failure to receive a heartbeat packet from the second host station comprises calculating a time difference by comparing a present time to the time stamp and determining that the time difference exceeds the timeout interval.

26. The first host station of claim 25 wherein the memory is further programmed to read a file comprising a plurality of remote network identifiers, wherein one of the plurality of remote network identifiers identifies the third network medium.

27. The first host station of claim 26 wherein the memory is further programmed to perform the step of periodically transmitting a heartbeat packet to each remote network identified by a corresponding remote network identifier in the file.

28. A method of operating a first host station to communicate with a second host station, comprising the steps of:

communicating a first packet from the first host station through a first interface of the first host station to a first network medium, wherein the first packet is further communicated from the first network medium through a first router station to a second network medium, and from the second network medium to a first interface of the second host station;

detecting a communications failure along a first communication path including the first interface of the first host station, the first network medium, the first router station, the second network medium, and the first interface of the second host station; and

responsive to the detected failure, redirecting communications addressed to pass from the first host station to the second host station to pass along a second communication path from the first host station to the second host station such that redirected communications are not attempted by the first host station to the second host station along the first communication path.

29. The method of claim 28 wherein the redirecting step comprises communicating a second packet along the second communication path comprising a path from a second interface of the first host station to a third network medium, from the third network medium through a second router station to a fourth network medium, and from the fourth network medium to a second interface of the second host station.

30. The method of claim 28 and further comprising the steps of:

detecting a communications failure along the second communication path; and

responsive to the detected failure along the second communication path, and having not detected a communications failure along the first communication path, redirecting communications addressed to pass from the first host station to the second host station along the first communication path.

31. The method of claim 28 and further comprising the step of operating the first host station to read a route table, wherein the redirecting step is responsive to the route table.

32. The method of claim 28 and further comprising the step of monitoring receipt of periodic heartbeat packets from the second host station, wherein the step of redirecting communications by the first host station is responsive to detecting a failure to receive a heartbeat packet from the second host station within a timeout interval.

33. The method of claim 32 and further comprising the steps of:

forming an internal timing table accessible by the first host station; and

responsive to receipt of a heartbeat packet, updating an entry in the internal timing table by entering a time stamp representative of a time when the heartbeat packet is received by the first host station.

34. The method of claim 33 wherein the step of detecting a failure to receive a heartbeat packet from the second host station comprises calculating a time difference by comparing a present time to the time stamp and determining that the time difference exceeds the timeout interval.

35. The method of claim 34 and further comprising the step of reading a file comprising a plurality of remote network identifiers, wherein one of the plurality of remote network identifiers identifies the second network medium.

36. The embodiment of claim 35 and further comprising the step of periodically transmitting a heartbeat packet to each remote network identified by a corresponding remote network identifier in the file.