Transmitting delay sensitive information over IP over frame relay

• US 6,430,196 B1
• Filed: 05/01/1998
• Issued: 08/06/2002
• Est. Priority Date: 05/01/1998
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Baroudi, Mihyar
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): VANDERPUYE, KENNETH N
• Application Number:
  US09/071,869
• Time in Patent Office: 1,558 Days
• Field of Search: 370/465, 370/466, 370/474, 370/470, 370/471, 370/395.5, 370/395.52, 370/469
• 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 47/35 by embedding flow control information in regular packets, e.g. piggybacking
• CPC Class Codes: H04L 47/43 Assembling or disassembling of packets, e.g. segmentation and reassembly [SAR]

Abstract

A method of transmitting delay sensitive information over Internet Protocol (IP) over Frame Relay including storing the information in an IP packet, storing the IP packet in a sub-frame, storing a special symbol representing that the frame is delay sensitive in the sub-frame, storing the sub-frame in a frame, storing a network layer protocol identification representing that the frame contains IP information in the frame, and transmitting the frame over a Frame Relay Network, distinguishing delay sensitive information from non-delay sensitive information by examining the special symbol. Additionally, in systems using the FRF.12 or similar fragmenting standard, the special symbol may be stored in the header of the fragment.

Claims

1. A method for transmitting delay sensitive information over IP over Frame Relay, including the steps of:

storing the delay sensitive information in an IP packet;

storing said IP packet in a Frame Relay sub-frame;

storing a payload type in a header in said sub-frame, said payload type representing that said sub-frame contains at least one IP packet that includes delay sensitive information;

storing said sub-frame in a Frame Relay frame; and

transmitting said frame over a Frame Relay network, distinguishing it from frames containing non-delay sensitive information based on said payload type stored in said header of said sub-frame.

2. The method of claim 1, wherein said transmitting step includes the step of:

distinguishing said frame from frames containing non-delay sensitive information if the payload type of any of the sub-frames within said frame indicates that the sub-frame is delay sensitive.

3. A method for transmitting delay sensitive information over IP over Frame Relay, including the steps of:

storing the delay sensitive information in an IP packet;

fragmenting said IP packet into one or more Frame Relay sub-frames;

storing a payload type in a header in each of said sub-frames, said payload type representing that said sub-frames contain at least one IP packet that includes delay sensitive information;

storing said sub-frames in one ore more Frame Relay frames; and

transmitting said frames over a Frame Relay network, distinguishing them from frames containing non-delay sensitive information based on said payload type stored in said header of said sub-frames.

4. The method of claim 3, wherein said storing said sub-frames step includes the step of:

storing each of said sub-frames in a different Frame Relay frame.

5. The method of claim 3, wherein said transmitting step includes the step of:

distinguishing said frames from frames containing non-delay sensitive information if the payload type of any of the sub-frames within each frame indicates that the sub-frame is delay sensitive.

6. A method for transmitting delay sensitive information over IP over Frame Relay, including the steps of:

storing the delay sensitive information in an IP packet;

storing said IP packet in a Frame Relay sub-frame;

storing a number in an unused portion of a header of said sub-frame representing that said sub-frame contains at least one IP packet that includes delay sensitive information;

storing said sub-frame in a Frame Relay frame; and

transmitting said frame over a Frame Relay network, distinguishing it from frames containing non-delay sensitive information based on said number stored in said unused portion of said header of said sub-frame.

7. The method of claim 6, wherein said transmitting step includes the step of:

distinguishing said frame from frames containing non-delay sensitive information if the unused portion of any of the sub-frames within said frame indicates that said sub-frame is delay sensitive.

8. The method of claim 6, wherein said unused portion of said header of said sub-frame is one of the spare fields of said header of said sub-frame.

9. A method for transmitting delay sensitive information over IP over Frame Relay, including the steps of:

storing the delay sensitive information in an IP packet;

fragmenting said IP packet into one or more Frame Relay sub-frames;

storing a number in an unused portion of a header in each of said sub-frames, said number representing that said sub-frames contain at least one IP packet that includes delay sensitive information;

storing said sub-frames in one or more Frame Relay frames; and

transmitting said frames over a Frame Relay network, distinguishing them from frames containing non-delay sensitive information based on said number stored in said unused portion of said header of said sub-frames.

10. The method of claim 9, wherein said storing said sub-frames step includes the step storing each of said sub-frames in a different Frame Relay frame.

11. The method of claim 9, wherein said header is an FRF.11 header having spare fields and said unused portion of said header of said sub-frames is one of the spare fields of said FRF.11 header of said sub-frames.

12. The method of claim 10, wherein said unused portion of said one or more fragments is the control bit field of said header of said sub-frames.

13. A method for transmitting delay sensitive information over IP over Frame Relay, including the steps of:

storing said delay sensitive information an IP packet;

storing said IP packet in a Frame Relay sub-frame;

storing a subchannel identification in a header in said sub-frame, said subchannel identification representing that said sub-frame contains at least one IP packet that includes delay sensitive information;

storing said sub-frame in said Frame Relay frame; and

transmitting said frame over a Frame Relay network, distinguishing it from frames containing non-delay sensitive IP information based on said subchannel identification stored in said header of said sub-frame.

14. The method of claim 13, wherein said transmitting step includes the step of:

distinguishing said frame from frames containing non-delay sensitive information if the subchannel identification of any of the sub-frames within the frame indicates that the sub-frame is delay sensitive.

15. A method for transmitting delay sensitive information over IP over Frame Relay, including the steps of:

storing the delay sensitive information in an IP packet;

fragmenting said IP packet into one or more Frame Relay sub-frames;

storing a subchannel identification in a header in each of said sub-frames, said subchannel identification representing that said sub-frames contain at least one IP packet that includes delay sensitive information;

storing said sub-frames in one or more Frame Relay frames; and

transmitting said frames over a Frame Relay network, distinguishing them from frames containing non-delay sensitive IP information based on said subchannel identification stored in said header of said sub-frames.

16. The method of claim 15, wherein said storing said sub-frames step includes the step of:

storing each of said sub-frames in a different Frame Relay frame.

17. A method for transmitting delay sensitive information over IP over Frame Relay, including the steps of:

storing the delay sensitive information in an IP packet;

storing said IP packet in a Frame Relay sub-frame;

storing a network layer protocol identification in said frame, said network layer protocol identification representing that said frame contains at least one IP packet that includes delay sensitive IP information;

storing said sub-frame in a Frame Relay frame; and

transmitting said frame over a Frame Relay network, distinguishing it from frames containing non-IP information and from frames containing non-delay sensitive IP information based on said network layer protocol identification stored in said sub-frame.

18. A method for processing a Frame Relay frame including the steps of:

examining payload types in headers of each of one or more sub-frames within the frame;

determining if information stored in the frame includes at least one IP packet that includes delay sensitive information based on the payload types stored in the headers of the sub-frames within the frame; and

giving the frame special priority if the frame includes at least one IP packet that includes delay-sensitive information.

19. The method of claim 18 wherein said determining step includes the step of:

determining that the frame is delay sensitive if the payload type of any of the sub-frames within the frame indicates that a sub-frame within the frame is delay sensitive.

20. The method of claim 18 further including routing the frame given the special priority prior to routing a frame with a lower priority.

21. A method for handling a Frame Relay frame including the steps of:

examining an unused portion in headers of each of one or more sub-frames within the frame;

determining if information stored in the frame includes at least one IP packet that includes delay sensitive information based on the number stored in the unused portion of the headers of the sub-frames within the frame;

giving the frame special priority if the frame includes at least one IP packet that includes delay-sensitive information.

22. The method of claim 21 wherein said determining step includes the step of:

determining that the frame is delay sensitive if numbers stored in the unused portion of any of the sub-frames within the frame indicates that a sub-frame within the frame is delay sensitive.

23. The method of claim 21, wherein said header is an FRF.11 header having spare fields and said unused portion is one of the spare fields of the FRF.11 header in each of said sub-frames.

24. The method of claim 21, wherein said unused portion is a control bit field of each of said sub-frame headers.

25. The method of claim 21 further including routing the frame given the special priority prior to routing a frame with a lower priority.

26. A method for processing a Frame Relay frame including the steps of:

examining subchannel identification in headers of each of one or more sub-frames within the frame;

determining if information stored in the frame is includes at least one IP packet that includes delay sensitive information based on the subchannel identification stored in the headers of the sub-frames within the frame;

giving the frame special priority if the frame includes at least one IP packet that includes delay-sensitive information.

27. The method of claim 26 wherein said determining step includes the steps of:

determining that the frame is delay sensitive if the subchannel identification of any of the sub-frames within the frame indicates that a sub-frame within the frame is delay sensitive.

28. The method of claim 26 further including routing the frame given the special priority prior to routing a frame with a lower priority.

29. A method of handling a Frame Relay frame including the steps of:

examining a network layer protocol identification in headers of each of one or more sub-frames within the frame;

determining if information stored in the frame is IP information based on the network layer protocol identification stored in the headers of,the sub-frames within the frame;

determining if the information stored in the frame is delay sensitive based on the network layer protocol identification stored in the headers of the sub-frames within the frame; and

giving the frame special priority if the frame is delay sensitive.

30. The method of claim 29 further including routing the frame given the special priority prior to routing a frame with a lower priority.