Apparatus and method for increasing reliability of data sensitive to packet loss

• US 20070189327A1
• Filed: 02/13/2006
• Published: 08/16/2007
• Est. Priority Date: 02/13/2006
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Konda, Praveen
• Granted Patent: US 7,924,890 B2
• Time in Patent Office: Days
• US Class Current: 370/466
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2408 for supporting different services, e.g. a differentiated services [DiffServ] type of service
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• CPC Class Codes: H04L 47/31 by tagging of packets, e.g. using discard eligibility [DE] bits
• CPC Class Codes: H04L 47/43 Assembling or disassembling of packets, e.g. segmentation and reassembly [SAR]
• CPC Class Codes: H04L 47/724 at intermediate nodes, e.g. resource reservation protocol [RSVP]
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04L 65/765 intermediate
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

An apparatus and method are provided which preferably increase reliability of data sensitive to packet loss. According to principles of the invention, a quality of service value may be dynamically assigned to network packets based on the contents of the network packets.

Claims

1. A method, comprising:

encoding an audio signal into audio packets;

converting the audio packets into network packets;

identifying contents of a network packet; and

assigning a quality of service value to the network packet according to the identified contents.

2. The method of claim 1, further comprising:

determining whether the network packet contains data sensitive to packet loss; and

tagging the network packet if it is determined to contain data sensitive to packet loss.

3. The method of claim 1, wherein assigning the quality of service value comprises changing one or more bits in a network packet header.

4. The method of claim 3, wherein the one or more bits are within one of a Type of Service (ToS) field or a Differentiated Services Code Point (DSCP) field.

5. The method of claim 1, wherein converting the audio packets comprises:

packetizing the audio packets using a Real-Time Transport Protocol (RTP).

6. The method of claim 5, further comprising:

assigning a dynamic range payload type to the RTP packets containing data sensitive to packet loss.

7. The method of claim 2, wherein the quality of service value assigned to the tagged network packet comprises a value different from the quality of service value assigned to network packets containing voice data.

8. The method of claim 2, wherein the quality of service value assigned to the tagged network packet provides a better quality of service than the quality of service assigned to network packets containing voice data.

9. The method of claim 2, wherein the data sensitive to packet loss includes signaling data for initiating communications between endpoint devices.

10. The method of claim 9, wherein the signaling data includes fax tones, modem tones, DTMF tones, and text relay tones.

11. The method of claim 2, further comprising:

reserving bandwidth for the network packets identified as sensitive to packet loss.

12. The method of claim 11, wherein reserving bandwidth comprises using Resource Reservation Protocol (RSVP).

13. A method, comprising:

receiving a sequence of network packets having sequence numbers to identify an order in which the network packets are transmitted from a transmit device;

detecting a packet loss in the sequence of network packets;

identifying contents of the received network packets; and

selectively sending a retransmission packet to the transmit device depending on the identified contents of the received network packets.

14. The method of claim 13, wherein detecting the packet loss comprises identifying a discontinuity in the sequence numbers of the received network packets.

15. The method of claim 13, further comprising:

determining whether the received network packets contain data sensitive to packet loss.

16. The method of claim 13, wherein selectively sending the retransmission packet to the transmit device comprises sending the retransmission packet when the sequence of network packets contains data sensitive to packet loss.

17. A network device, comprising:

an encoder that encodes an audio signal into audio packets; and

a processor adapted to convert the audio packets into network packets, identify contents of the network packets, and assign a quality of service priority setting to the network packets according to the identified contents of the network packets.

18. The network device of claim 17, wherein the quality of service priority setting includes one or more bits associated with a Type of Service (ToS) field or a Differentiated Services Code Point (DSCP) field.

19. The network device of claim 17, wherein the processor is further adapted to determine whether the network packets contain data sensitive to packet loss and tag the network packets determined to contain data sensitive to packet loss.

20. The network device of claim 19, further comprising:

a jitter buffer to store the received network packets; and

a buffer to store the tagged network packets when the jitter buffer overflows.

21. A network device, comprising:

means for encoding an audio signal into audio packets;

means for converting the audio packets into network packets;

means for identifying contents of the network packets; and

means for assigning a quality of service value to the network packets based on the identified contents.

22. The network device of claim 21, further comprising:

means for determining whether the network packets contain data sensitive to packet loss; and

means for tagging network packets determined to contain data sensitive to packet loss.

23. The network device of claim 21, wherein the means for assigning the quality of service value comprises means for changing one or more bits in a network packet header.

24. The network device of claim 23, wherein the one or more bits are within one of a Type of Service (ToS) field or a Differentiated Services Code Point (DSCP) field.

25. The network device of claim 21, wherein the means for converting the audio packets comprises means for packetizing the audio packets using a Real-Time Transport Protocol (RTP).

26. The network device of claim 25, further comprising:

means for assigning a dynamic range payload type to the RTP packets containing data sensitive to packet loss.

27. The network device of claim 22, further comprising:

means for reserving bandwidth for the network packets identified as sensitive to packet loss.

28. A network device, comprising:

means for receiving a sequence of network packets having sequence numbers to identify an order in which the network packets are transmitted from a transmit device;

means for detecting packet loss in the sequence of network packets;

means for identifying contents of the received network packets; and

means for selectively sending a retransmission packet to the transmit device depending on the identified contents of the received network packets.

29. The network device of claim 28, wherein the means for detecting packet loss comprises means for identifying a discontinuity in the sequence numbers of the received network packets.

30. The network device of claim 28, further comprising:

means for determining whether the received network packets contain data sensitive to packet loss.

31. The method of claim 28, wherein the means for selectively sending the retransmission packet to the transmit device comprises means for sending the retransmission packet when the sequence of network packets contain data sensitive to packet loss.

32. An article of computer-readable medium containing instructions that, when executed, cause the computer to:

encode an audio signal into audio packets;

convert the audio packets into network packets;

identify contents of a network packet; and

assign a quality of service value to the network packet according to the identified contents.

33. The article of claim 32, further comprising instructions that, when executed, cause the computer to:

determine whether the network packet contains data sensitive to packet loss; and

tag the network packet if it is determined to contain data sensitive to packet loss.

34. The article of claim 32, wherein the instructions that, when executed, cause the computer to assign the quality of service value comprise instructions that, when executed, cause the computer to change one or more bits in a network packet header.

35. The article of claim 34, wherein the one or more bits are within one of a Type of Service (ToS) field or a Differentiated Services Code Point (DSCP) field.

36. The article of claim 32, wherein the instructions that, when executed, further cause the computer to convert the audio packets comprise instructions that, when executed, further cause the computer to packetize the audio packets using a Real-Time Transport Protocol (RTP).

37. The article of claim 36, further comprising instructions that, when executed, cause the computer to:

assign a dynamic range payload type to the RTP packets containing data sensitive to packet loss.

38. The article of claim 32, further comprising instructions that, when executed, cause the computer to:

reserve bandwidth for the network packets identified as sensitive to packet loss.

39. An article of computer-readable medium containing instructions that, when executed, cause the computer to:

receive a sequence of network packets having sequence numbers to identify an order in which the network packets are transmitted from a transmit device;

detect a packet loss in the sequence of network packets;

identify contents of the received network packets; and

selectively send a retransmission packet to the transmit device depending on the identified contents of the received network packets.

40. The article of claim 39, wherein the instructions that, when executed, cause the computer to detect the packet loss comprise instructions that, when executed, cause the computer to identify a discontinuity in the sequence numbers of the received network packets.

41. The article of claim 39, further comprising instructions that, when executed, cause the computer to determine whether the received network packets contain data sensitive to packet loss.

42. The article of claim 39, wherein the instructions that, when executed, cause the computer to selectively send the retransmission packet to the transmit device comprise instructions that, when executed, cause the computer to send the retransmission packet when the sequence of network packets contain data sensitive to packet loss.