Segmented permanent virtual circuits

• US 6,292,495 B1
• Filed: 04/10/1998
• Issued: 09/18/2001
• Est. Priority Date: 04/10/1998
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Von Hammerstein, Charles G., Simon, Robert
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): VANDERPUYE, KENNETH N
• Application Number:
  US09/058,874
• Time in Patent Office: 1,257 Days
• Field of Search: 370/389, 370/395, 370/428, 370/466, 370/474, 370/465, 370/396, 370/397, 370/400-409, 370/470, 370/477
• US Class Current: 370/465
• CPC Class Codes: H04L 41/00 Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
• CPC Class Codes: H04L 41/40 using virtualisation of network functions or resources, e.g. SDN or NFV entities

Abstract

An apparatus and method for communicating link status information for permanent virtual circuits that share a data link connection identifier. A first frame relay packet that includes link status information for a plurality of virtual circuits that each share a first data link connection identifier is received via a frame relay network. Using the link status information in the first frame relay packet, a second frame relay packet that conforms to a standard local management interface status message format is generated. The second frame relay packet is transmitted to customer premise equipment.

Claims

1. A method comprising:

receiving via a frame relay network a first frame relay packet that includes link status information for a plurality of virtual circuits that each share a first data link connection identifier;

generating a second frame relay packet that conforms to a standard local management interface status message format using the link status information in the first frame relay packet; and

transmitting the second frame relay packet to customer premise equipment.

2. The method of claim 1 wherein transmitting the second frame relay packet comprises transmitting the second frame relay packet to a router that is connected to a local area network.

3. The method of claim 1 wherein receiving a first frame relay packet that includes link status information comprises receiving a first frame relay packet having link status bits that are positioned at respective bit positions in a stream of bits that constitute the first frame relay packet, each of the respective bit positions corresponding a respective one of the plurality of virtual circuits.

4. The method of claim 1 wherein receiving a first frame relay packet that includes link status information comprises receiving link status bits that are associated with the plurality of virtual circuits according to their respective bit positions in the first frame relay packet.

5. The method of claim 1 wherein receiving a first frame relay packet comprises receiving a plurality of identifiers that each identify a respective one of the plurality of virtual circuits, each of the plurality of identifiers being arranged with a portion of the link status information that pertains to the identified one of the plurality of virtual circuits.

6. The method of claim 1 wherein the link status information includes connection status bits that indicate for each of the plurality of virtual circuits whether the virtual circuit is active.

7. The method of claim 1 wherein the link status information includes congestion status bits that indicate for each of the plurality of virtual circuits whether the virtual circuit is congested.

8. The method of claim 1 further comprising:

packing the first frame relay packet with link status information according to either a first format or a second format depending on which is more compact; and

transmitting the first frame relay packet via the frame relay network.

9. The method of claim 8 wherein packing the first frame relay packet according to the first format comprises packing link status bits in respective bit positions of the first frame relay packet to indicate to which of the plurality of virtual circuits each of the link status bits pertains.

10. The method of claim 8 wherein packing the first frame relay packet according to the second format comprises packing link status bits together with identifying values that indicate to which of the plurality of virtual circuits each of the link status bits pertains.

11. The method of claim 1 wherein generating the second frame relay packet comprises including in the second frame relay packet a respective data link connection identifier for each of the plurality of virtual circuits that share the first data link connection identifier.

13. The method of claim 11 further comprising the steps of

receiving the third frame relay frame and the fourth frame relay frame;

looking up the first data link connection identifier and the second data link connection identifier from respective look-up table entries indicated by the first and second multiplexing values in the third frame relay frame and the fourth frame relay frame, respectively; and

transmitting contents of the third frame relay frame to a second routing device in a fifth frame relay frame that includes the first data link connection identifier.

12. A method comprising:

receiving from a first routing device a first frame relay frame having a first data link connection identifier and a second frame relay frame having a second data link connection identifier, the first data link connection identifier being different from the second data link connection identifier;

looking up a first multiplexing value and a second multiplexing value from respective look-up table entries indicated by the first data link connection identifier and the second data link connection identifier; and

transmitting contents of the first frame relay frame across a frame relay network in third frame relay frame that includes a third data link connection identifier and the first multiplexing value; and

transmitting contents of the second frame relay frame across the frame relay network in a fourth frame relay frame that includes the third data link connection identifier and the second multiplexing value.

14. A method comprising:

receiving a first frame relay packet that includes link status information for each of a plurality of permanent virtual circuits that share a common data link connection identifier;

looking up respective data link connection identifiers for the plurality of permanent virtual circuits; and

transmitting the looked-up data link connection identifiers and the link status information to a routing device in a second frame relay packet.

15. The method of claim 14 wherein the second frame relay frame is organized into respective information elements, each information element including a respective one of the looked-up data link connection identifiers and the link status information for a respective one of the plurality of virtual circuits.

16. The method of claim 14 wherein the second frame relay frame conforms to a standard local management interface status message format.

17. A frame relay access device comprising:

receive logic to receive via a frame relay network a first frame relay packet that includes link status information for a plurality of virtual circuits that each share a first data link connection identifier;

status message generation logic to generate a second frame relay packet that conforms to a standard local management interface status message and that includes the link status information in the first frame relay packet; and

a transmitter to transmit the second frame relay packet to customer premise equipment.

18. The frame relay access device of claim 17 further comprising audio regeneration logic to receive via the frame relay network voice frames that contain digitized audio signals and to generate audio frequency analog signals therefrom.

19. The frame relay access device of claim 17 wherein the status message generation logic includes logic to inspect a value in the first frame relay packet to determine whether the linked status information in the first frame relay packet is in a first format or a second format.

20. The frame relay access device of claim 17 wherein the status message generation logic includes logic to include in the second frame relay packet a respective data link connection identifier for each of the plurality of virtual circuits that share the first data link connection identifier.

21. The frame relay access device of claim 17 wherein the status message generation logic is at least partly implemented by a programmed processor.

22. The frame relay access device of claim 17 wherein the link status information includes connection status information indicating for each of the plurality of virtual circuits whether the virtual circuit is active.

23. The frame relay access device of claim 17 wherein the link status information includes congestion status information indicating for each of the plurality of virtual circuits whether the virtual circuit is congested.

24. A frame relay access device comprising:

means for receiving via a frame relay network a first frame relay packet that includes link status information for a plurality of virtual circuits that each share a first data link connection identifier;

means for generating a second frame relay packet that conforms to a standard local management interface format using the link status information in the first frame relay packet; and

means for transmitting the second frame relay packet to customer premise equipment.

25. The frame relay access device of claim 24 wherein the means for generating a second frame relay packet comprises means for including in the second frame relay packet a respective data link connection identifier for each of the plurality of virtual circuits that share the first data link connection identifier.

26. The frame relay access device of claim 24 wherein the link status information includes connection status information indicating for each of the plurality of virtual circuits whether the virtual circuit is active.

27. The frame relay access device of claim 24 wherein the link status information includes congestion status information indicating for each of the plurality of virtual circuits whether the virtual circuit is congested.