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

• US 7,924,890 B2
• Filed: 02/13/2006
• Issued: 04/12/2011
• 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
• Primary Examiner(s): Trost, IV; William
• Assistant Examiner(s): Liu; Siming
• Application Number:
  US11/353,508
• Publication Number:
  US 20070189327A1
• Time in Patent Office: 1,884 Days
• Field of Search: 370/464, 370/465, 370/466, 370/526, 370/528, 709/230, 709/231
• US Class Current: 370/526
• 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 network device, comprising:

an encoder to encode an audio signal into one or more audio packets;

a processing system to convert the one or more audio packets into one or more network packets, identify contents of the one or more network packets, and assign a quality of service priority setting to each of the one or more network packets according to the identified contents of the one or more network packets, and when the audio signal includes signal tone data for initiating communications between endpoint devices, the processing system is configured to assign one of a plurality of high priority settings to the corresponding network packets based on a type of signal tone data included in the audio signal, wherein the processing system is configured to include the assigned high priority setting in the corresponding network packets.

2. The network device of claim 1, 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.

3. The network device of claim 1, wherein the quality of service priority setting assigned to network packets associated with the signal tone data for initiating communications between endpoint devices comprises a higher priority setting than the quality of service priority setting assigned to network packets containing voice data, and wherein the quality of service priority setting assigned to network packets associated with a fax tone, a modem tone, a TeleTYpewriter (TTY) tone, a Telecommunications Device for the Deaf (TDD) tone, or a text relay tone comprise a higher priority setting than the quality of service priority setting assigned to network packets containing voice data.

4. The network device of claim 1, wherein the signal tone data for initiating communications between endpoint devices comprises a fax tone, a modem tone, a TeleTYpewriter (TTY) tone, a Telecommunications Device for the Deaf (TDD) tone, or a text relay tone.

5. The network device of claim 1, wherein the signal tone data for initiating communications between endpoint devices comprises Dual Tone Multi-Frequency (DTMF) data, fax tone data, modem tone data, and teletypewriter (TTY) tone data, wherein the high priority setting associated with the Dual Tone Multi-Frequency (DTMF) data is larger than the high priority setting associated with the fax tone data, the modem tone data, and the teletypewriter (TTY) tone data, and wherein the high priority setting associated with the fax tone data and the modem tone data is larger than the high priority setting associated with the teletypewriter (TTY) tone data.

6. 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 priority value to each of the network packets based on the identified contents, when the audio signal includes signal tone data for initiating communications between endpoint devices, the means for assigning is configured to assign one of a plurality of high priority values to the corresponding network packets based on a type of signal tone data included in the audio signal, wherein the means for assigning is configured to include the assigned high priority values in the corresponding network packets.

7. The network device of claim 6, wherein the quality of service priority value assigned to network packets associated with the signal tone data for initiating communications between endpoint devices comprises a higher priority value than the quality of service priority value assigned to network packets containing voice data.

8. The network device of claim 6, wherein the means for assigning the quality of service priority value comprises means for changing one or more bits in a network packet header.

9. The network device of claim 8, wherein the one or more bits are within one of a Type of Service (ToS) field or a Differentiated Services Code Point (DSCP) field.

10. The network device of claim 6, wherein the means for converting the audio packets comprises means for packetizing the audio packets using a Real-Time Transport Protocol (RTP).

11. The network device of claim 10, further comprising:

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

12. The network device of claim 7, further comprising:

means for reserving bandwidth for the network packets having the higher priority value.

13. The network device of claim 6, wherein the signal tone data for initiating communications between endpoint devices comprises a fax tone, a modem tone, a TeleTYpewriter (TTY) tone, a Telecommunications Device for the Deaf (TDD) tone, or a text relay tone.

14. The network device of claim 6, wherein the signal tone data for initiating communications between endpoint devices comprises Dual Tone Multi-Frequency (DTMF) data, fax tone data, modem tone data, and teletypewriter (TTY) tone data, wherein the high priority setting associated with the Dual Tone Multi-Frequency (DTMF) data is larger than the high priority setting associated with the fax tone data, the modem tone data, and the teletypewriter (TTY) tone data, and wherein the high priority setting associated with the fax tone data and the modem tone data is larger than the high priority setting associated with the teletypewriter (TTY) tone data.

15. A network device, comprising:

means for receiving network packets over a network, wherein the network packets include corresponding priority settings, wherein the priority settings have corresponding values that are based on whether the received network packets include at least a portion of a signaling tone utilized to establish a communication session between endpoint devices and based on which type of signaling tone is included in the received network packets;

means for analyzing the priority settings included in the received network packets to determine whether the received network packets are sensitive to packet loss, wherein network packets that are sensitive to packet loss include at least a portion of a signaling tone utilized to establish communication sessions between endpoint devices;

means for jitter buffering the network packets received over the network; and

means for storing one or more of the received network packets that are determined to be sensitive to packet loss based on the priority settings when the means for jitter buffering is full and unable to store the received network packets.

16. A computer-readable memory including instructions configured to cause at least one device 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 priority value to each of the network packets according to the identified contents, when the audio signal includes signal tone data for initiating communications between endpoint devices, the at least one device is configured to assign one of a plurality of high priority values to the corresponding network packets based on a type of signal tone data present in the audio signal and include the assigned high priority values in the corresponding network packets.

17. The computer-readable medium of claim 16, wherein the instructions are further configured 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.

18. The computer-readable medium of claim 16, wherein the instructions are further configured to change one or more bits in a network packet header to assign the quality of service priority value, and wherein the one or more bits are within one of a Type of Service (ToS) field or a Differentiated Services Code Point (DSCP) field.

19. The computer-readable medium of claim 16, wherein the instructions are further configured to packetize the audio packets using a Real-Time Transport Protocol (RTP) to convert the audio packets, and wherein the instructions are further configured to assign a dynamic range payload type to the RTP packets containing data sensitive to packet loss.

20. The computer-readable medium of claim 17, wherein the instructions are further configured to:

reserve bandwidth for the tagged network packet.

21. The computer-readable memory of claim 16, wherein the quality of service priority value assigned to network packets associated with the fax tone device, the modem tone device, the TeleTYpewriter (TTY), the Telecommunications Device for the Deaf (TDD), or the text relay tone device comprises a higher priority value than the quality of service priority value assigned to network packets containing voice data.

22. The computer-readable memory of claim 16, wherein the instructions are further configured to reserve bandwidth for the network packets having a high priority value.

23. The computer-readable memory of claim 22, wherein reserving bandwidth comprises using Resource Reservation Protocol (RSVP).

24. The computer-readable medium of claim 23, wherein the endpoint devices further comprise a Dual Tone Multi-Frequency (DTMF) device, wherein the signal tone data for initiating communications between endpoint devices comprises Dual Tone Multi-Frequency (DTMF) data, fax tone data, modem tone data, and teletypewriter (TTY) tone data, wherein the high priority setting associated with the Dual Tone Multi-Frequency (DTMF) data is larger than the high priority setting associated with the fax tone data, the modem tone data, and the teletypewriter (TTY) tone data, and wherein the high priority setting associated with the fax tone data and the modem tone data is larger than the high priority setting associated with the teletypewriter (TTY) tone data.

25. A computer-readable memory including instructions configured to cause at least one device to:

receive network packets over a network, wherein the network packets include corresponding priority settings, wherein the priority settings have corresponding values that are based on whether the received network packets include at least a portion of a signaling tone utilized to establish a communication session between endpoint devices and based on which type of signaling tone is included in the received network packets;

determine whether at least one of the received network packets is sensitive to packet loss based on the priority settings included in the received network packets, wherein network packets that are sensitive to packet loss include at least a portion of a signaling tone utilized for initiating communications between endpoint devices;

store the network packets received over the network in a jitter buffer; and

when the jitter buffer is full and unable to store the received network packets, store one or more of the received network packets that are determined to be sensitive to packet loss based on the priority settings in a different buffer.

26. A network device, comprising:

a processor adapted to convert an audio signal into network packets, identify contents of the network packets, and assign a quality of service priority value to each of the network packets according to the identified contents of the network packets, when the audio signal includes signaling data for initiating communications between endpoint devices, the processor is configured to assign one of a plurality of high priority values and insert the assigned high priority values in the corresponding network packets based on a type of signaling data present in the audio signal.

27. The network device of claim 26, wherein the signaling data for initiating communications between endpoint devices comprises a fax tone, a modem tone, a Dual Tone Multi-Frequency (DTMF) tone, a TeleTYpewriter (TTY) tone, a Telecommunications Device for the Deaf (TDD) tone, or a text relay tone.

28. The network device of claim 26, wherein the quality of service priority value assigned to the network packets associated with the signaling data for initiating communications between endpoint devices is higher than a priority value assigned to network packets containing voice data.

29. A network device, comprising:

a processor adapted to receive network packets over a network, wherein the network packets include corresponding priority settings, wherein the priority settings have corresponding values that are based on whether the received network packets include at least a portion of a signaling tone utilized to establish a communication session between endpoint devices and based on which type of signaling tone is included in the received network packets, and wherein the processor is configured to determine whether at least one of the received network packets is sensitive to packet loss based on the priority settings included in the received network packets, wherein network packets that are sensitive to packet loss include at least a portion of a signaling tone utilized for initiating communications between endpoint devices;

a jitter buffer configured to store one or more of the network packets received over the network; and

a buffer allocated to store the received network packets that are determined to be sensitive to packet loss based on the priority settings when the jitter buffer is full and unable to store the received network packets.