Method and apparatus for providing an interface between a plurality of frame relay networks

• US 6,209,039 B1
• Filed: 10/16/1998
• Issued: 03/27/2001
• Est. Priority Date: 10/16/1998
• Status: Expired due to Term

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: MCI WorldCom, Inc. (Verizon Communications Inc.)
• Inventors: Williams, James F., Frost, Todd W., Albright, Martin, Chen, William C., Fontenot, Michael D.
• Primary Examiner(s): Maung, Zarni
• Assistant Examiner(s): NGUYEN, THU HA T
• Application Number:
  US09/173,949
• Time in Patent Office: 893 Days
• Field of Search: 709/211, 709/249, 709/54, 709/208-209, 370/219, 370/228, 370/248, 370/351, 370/489, 370/901, 340/825
• US Class Current: 709/249
• CPC Class Codes: H04L 12/2854 Wide area networks, e.g. public data networks

Abstract

A system, method, and computer program product for providing a resilient network-to-network interface (RNNI) between a first frame relay network and a second frame relay network. The RNNI comprises a plurality of data links that connect a master node in the first network to a slave node in the second network. The RNNI is initialized by operating an independent instance of a Link Integrity Verification (LIV) routine on each of the data links, returning an UP or DOWN status. One of the data links is designated as the ACTIVE data link, and the remaining data links are designated as INACTIVE. Once the RNNI is initialized, the ACTIVE data link is monitored using RNNI link management procedures including the LIV routine and a Permanent Virtual Circuit (PVC) polling routine, and the INACTIVE data links are monitored using the LIV routine.

Claims

1. A resilient network-to-network interface (RNNI) between a first frame relay network and a second frame relay network, wherein the first network includes a master node and the second network includes a slave node, the RNNI comprising:

a plurality of data links between the master node and the slave node, wherein the plurality of data links comprise;

an independent instance of a Link Integrity Verification (LIV) routine on each of the data links that determines the status of the data links;

a detector for detecting operational status of the data links as determined by the LIV routine; and

a designator for designating one of a plurality of constituent links of the RNNI with UP status as ACTIVE and designating the rest of the constituent links of the RNNI as INACTIVE.

2. The RNNI of claim 1 further comprising the master node sending a PVC poll status message to the slave node over the ACTIVE link, wherein the slave node recognizes the ACTIVE link on receipt of the PVC poll status message.

3. The RNNI of claim 1, wherein the ACTIVE link is monitored using an LIV routine and a PVC polling routine such that the ACTIVE link is changed to INACTIVE if the LIV routine returns a DOWN status and each of the INACTIVE data links are monitored using the LIV routine.

4. The RNNI of claim 3 further comprising notifying a network administrator if one of a first monitoring means and a second monitoring means returns a DOWN status.

5. The RNNI of claim 1, wherein the LIV routine includes Annex A Link Integrity Verification without periodic PVC polling.

6. The RNNI of claim 1, wherein the LIV routine includes Annex D Link Integrity Verification without periodic PVC polling.

7. The RNNI of claim 1, wherein the LIV routine is operative to send an initial sequence number from a first node to a second node over a data link under test thereby resulting in a received sequence number, wherein the sequence number is a binary number, send the received sequence number from the second node back to the first node over the data link under test thereby resulting in a sequence number, determine if the sequence number is the same as the initial sequence number, and increment the sequence number through a predetermined binary sequence to generate a second sequence number, if the sequence number is received correctly.

8. The RNNI of claim 7, further comprising assigning an UP status for the data link under test when a certain number of successful cycles have been completed.

9. A method of initializing a resilient network-to-network interface (RNNI) between a master node in a first frame relay network and a slave node in a second frame relay network, wherein the RNNI comprises a plurality of data links connecting the master and slave nodes, the method comprising the steps of:

operating an independent instance of a Link Integrity Verification (LIV) routine on each of the data links to determine the status of the data links;

detecting which of the data links have received an UP status from the LIV routine;

designating one of the data links with an UP status as ACTIVE and the remaining data links as INACTIVE; and

sending a PVC poll status message from the master node to the slave node over the ACTIVE link, wherein the slave node recognizes the ACTIVE link on receipt of the PVC poll status message.

10. The method of claim 9 further comprising the step of monitoring the RNNI, wherein the step of monitoring the RNNI comprises the steps of:

monitoring the ACTIVE link with network-to-network interface (NNI) link management procedures comprising an LIV routine and a PVC polling routine;

changing the state of the ACTIVE link to INACTIVE if the LIV routine of the NNI returns a DOWN status and repeating the steps of operating, detecting, designating, and sending; and

monitoring each of the INACTIVE data links with the LIV routine.

11. The method of claim 10 further comprising the step of notifying a network administrator if one of the ACTIVE link monitoring step and the INACTIVE link monitoring step returns a DOWN status.

12. The method of claim 10 further comprising repeating the ACTIVE link monitoring step, the changing step, and the INACTIVE link monitoring step.

13. The method of claim 9, wherein the operating step comprises operating an independent instance of Annex A of ITU-T Recommendation Q.933 without periodic PVC polling on each of the data links to determine the status of each of the data links.

14. The method of claim 9, wherein the operating step comprises operating an independent instance of Annex D from ANSI standard T1.617 without periodic PVC polling on each of the data links to determine the status of the data links.

15. A computer program resident on a computer for operating a resilient network-to-network interface (RNNI) between a first frame relay network and a second frame relay network connected by a plurality of data links, the computer program comprising:

a first program code for causing the computer to operate an independent instance of a Link Integrity Verification (LIV) routine on each of the data links to determine the status of each of the data links;

a second program code for causing the computer to detect which of the data links have received an UP status from the LIV routine;

a third program code for designating one of the data links with the UP status as ACTIVE and the remaining data links as INACTIVE; and

a fourth program code for sending a PVC poll status message over the ACTIVE link.

16. The computer program of claim 15 further comprising:

a fifth program code for causing the computer to monitor the ACTIVE link with network-to-network interface (NNI) link management procedures comprising an LIV routine and a PVC polling routine;

a sixth program code for causing the computer to change the state of the ACTIVE link to INACTIVE if the LIV routine of the NNI returns a DOWN status and causing the first program code, the second program code, the third program code, and the fourth program code to be executed again; and

a seventh program code for causing the computer to monitor each of the INACTIVE data links with the LIV routine of the NNI.

17. The computer program of claim 16, wherein the computer program logic further comprises an eighth program code for notifying a network administrator if one of the fifth program code and the seventh program code returns a DOWN status.

18. The computer program of claim 15, wherein the LIV routine includes Annex A of ITU-T Recommendation Q.933 without periodic PVC polling.

19. The computer program of claim 15, wherein the LIV routine includes Annex D from ANSI standard T1.617 without periodic PVC polling.

20. A network-to-network interface (NNI) comprising:

a plurality of data links connecting a master node in a first frame relay network to a slave node in a second frame relay network, the plurality of data links comprising;

a monitor for monitoring the status of each of the data links;

a detector for detecting which of the data links have received an UP status from the monitor;

a designator for designating one of the data links with an UP status as ACTIVE and designating the remaining data links as INACTIVE; and

a PVC poll status message sent from the master node to the slave node over the ACTIVE link, wherein the slave node recognizes the ACTIVE link on receipt of the PVC poll status message.

21. The NNI of claim 20,wherein the ACTIVE data link and the INACTIVE data links are monitored, and the ACTIVE data link is changed to INACTIVE if the monitor returns a DOWN status for the ACTIVE data link.

22. The NNI of claim 21 further comprising notifying a network administrator if one of the INACTIVE data links returns the DOWN status.