Method and apparatus for adaptive prioritization of multiple information types in highly congested communication devices

• US 6,130,880 A
• Filed: 03/20/1998
• Issued: 10/10/2000
• Est. Priority Date: 03/20/1998
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Schuster, Guido M., Naudus, Stanley T., Szczepucha, Chester
• Primary Examiner(s): Hsu, Alpus H.
• Assistant Examiner(s): HO, DUC CHI
• Application Number:
  US09/044,958
• Time in Patent Office: 935 Days
• Field of Search: 370/235, 370/237, 370/230, 370/231, 370/229, 370/400, 370/412, 370/401, 370/466, 370/468, 370/465, 370/477
• US Class Current: 370/235
• CPC Class Codes: H04L 47/24 Traffic characterised by specific attributes, e.g. priority or QoS
• CPC Class Codes: H04L 47/29 using a combination of thresholds
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method and apparatus are used in a gateway to discard selected frames received with a selected encoded-information-type from a communication link with a larger bandwidth to avoid overflowing an internal delay variance removing queue used for protocol translation to a communication link with a smaller bandwidth. The discarded frames do not decrease the quality of translated information. A visual delay variance removing queue congestion indicator is included to indicate three levels of congestion in the delay variance removing queue for received frames. The method and apparatus are used in a multimedia gateway which is translating audio/video conferencing protocols (e.g., H.320, H.323/LAN H.323/PPP and H.324) received from a communication link with a large bandwidth and sent to a communication link with a smaller bandwidth.

Claims

1. A method of adaptively prioritizing between two or more encoded-information-types received over a communication link in a plurality of frames in an internetworking device, the frames including a plurality of data bits, the method comprising the following steps:

receiving a plurality of frames for a first network protocol over a first communication link having a first communication bandwidth, the plurality of frames having one of a plurality of encoded-information-types;

storing the received frames in a delay variance removing queue in a memory in the internetworking device, the delay variance removing queue allowing the internetworking device to compensate for sequencing or timing relationships used in the first network protocol;

translating the frames from the delay variance removing queue into a second network protocol;

determining periodically whether a number of frames arriving on the first network connection exceeds a predetermined queue congestion threshold, and if so,

selecting an encoded-information-type encoded in a frame to store in the delay variance removing queue;

discarding received frames that do not have the selected encoded-information-type until enough frames in the delay variance removing queue have been processed so the delay variance removing queue reaches a predetermined length; and

sending the translated frames for the second network protocol over a second communication link having a second communication bandwidth, the second communication bandwidth being less than the first communication bandwidth.

2. A computer readable medium having stored therein instructions for causing a central processing unit to execute the method of claim 1.

3. The method of claim 1 wherein the step of discarding received frames includes:

determining a first location in the delay variance removing queue containing a first frame with the selected encoded-information-type;

determining a second location in the delay variance removing queue containing a second frame with the selected encoded-information-type; and

discarding other frames in other locations in the delay variance removing queue between the first and second locations, thereby increasing space in the delay variance removing queue.

4. The method of claim 1 wherein the step of discarding received frames includes:

determining a first location in the delay variance removing queue containing a first frame with the selected encoded-information-type; and

discarding other frames in locations in the delay variance removing queue prior to the first location, thereby increasing space in the delay variance removing queue.

5. The method of claim 1 wherein the step of discarding received frames includes:

discarding frames that do not have the selected encoded-information-type until X-number of frames have been received or a frame with the selected encoded-information-type is received.

6. The method of claim 1 wherein the step of discarding received frames includes:

sending a first flow control message over the first communication link requesting frames be sent at less than the first communication bandwidth;

setting a timer with a predetermined congestion control value; and

upon expiration of the timer, sending a second flow control message over the first communication link requesting frames again be sent at the first communication bandwidth.

7. The method of claim 6 wherein the first and second flow control messages are sent with the H.245 control protocol for multimedia communication.

8. The method of claim 1 wherein the step of discarding received frames includes:

determining a time period when a frame with the selected encoded-information-type is received;

setting a timer with the time period; and

discarding frames received until the timer expires or a frame with the selected encoded-information-type is received.

9. The method of claim 1 further comprising:

receiving a selection input with a time period for continuously receiving frames with a new encoded-information-type;

setting a timer with the time period; and

discarding frames received that do not have the new encoded-information-type until the time expires.

10. The method of claim 1 wherein the first communication link is communication link to a local area network communication link and the second communication link is a serial line communication link.

12. The method of claim 1 wherein the step of selecting an encoded-information-type includes selecting a H.263 I-frame as the encoded-information-type.

13. The method of claim 1 wherein the discarding step includes discarding received frames having an encoded-information-type of any of H.263 P-frames, frames or PB-frames.

14. The method of claim 1 wherein the step of discarding received frames includes:

determining whether a first frame with the selected encoded-information-type is in the delay variance removing queue, and if not,

discarding received frames that do not have the selected encoded-information-type until a frame with the selected encoded-information-type is received.

15. The method of claim 1 wherein the first and second communication links have two or more virtual channels for sending and receiving frames and the two or more virtual channels include a first virtual channel for audio information, a second virtual channel for video information and a third channel for data information.

16. The method of claim 1 wherein the plurality of frames received over the communication link include any of H.225 or H.223 frames.

17. The method of claim 1 wherein the delay variance removing queue is a buffer that is used to translate network protocols that do not require timing synchronization with a delay variance removing queue.

11. The method of clam 1 wherein the first network protocol is H.323 and the second network protocol is any of H.320, H.323 over a LAN, H.323 over PPP or H.324.

18. An internetworking apparatus for translating a plurality of frames received for a first network protocol over a first communication link having a first communication bandwidth, the plurality of frames having one of a plurality of encoded-information-types into a second network protocol sent over a second communication link having a second communication bandwidth, the apparatus comprising:

a delay variance removing queue, for allowing the internetworking device to compensate for sequencing or timing relationships used in a first network protocol;

a translator, for translating frames from the first network protocol stored in the delay variance removing queue into a second network protocol; and

a queue congestion threshold for discarding received frames that do have a selected encoded-information-type until enough frames in the delay variance removing queue are processed so the delay variance removing queue reaches a predetermined length.

19. The internetworking apparatus of claim 18 wherein the delay variance removing queue is a buffer that is used to translate network protocols that do not require timing synchronization with a delay variance removing queue.