Systems and methods for implementing end-to-end checksum

• US 7,284,181 B1
• Filed: 04/24/2002
• Issued: 10/16/2007
• Est. Priority Date: 04/24/2002
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Venkatramani, Anjan
• Primary Examiner(s): Lamarre; Guy
• Assistant Examiner(s): CHAUDRY, MUJTABA M
• Application Number:
  US10/128,255
• Time in Patent Office: 2,001 Days
• Field of Search: 714/755, 714/758, 714/757, 714/749, 714/746, 714/49, 714/776, 709/224, 709/245, 370/471, 370/465, 370/473, 360/251, 711/206
• US Class Current: 714/758
• CPC Class Codes: H03M 13/09 Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0085 Formatting with cells
• CPC Class Codes: H04L 49/555 Error detection

Abstract

A network device includes interface logic and processing logic. The interface logic receives data. The processing logic generates a checksum of the data and fragments the data into one or more cells. The processing logic further determines whether one of the one or more cells includes at least one of cell overhead bytes and cell pad bytes, and selectively inserts the checksum into the at least one of cell overhead bytes and pad bytes based on the determination.

Claims

1. A method of processing data in a network device, comprising:

receiving data on an incoming path of the network device;

generating an error detection code for the received data;

fragmenting the data into one or more cells;

inserting the error detection code into one of the cells;

determining an outgoing path of the network device for the data based on destination information;

forwarding the cells to the outgoing path;

extracting, at the outgoing path of the network device, the inserted error detection code from the cell;

re-forming the data from the one or more cells; and

checking for data errors using the extracted error detection code.

2. The method of claim 1, wherein the error detection code comprises a cyclic redundancy check (CRC) value.

3. The method of claim 2, wherein generating an error detection code further comprises:

generating the CRC value using a CRC generator polynomial.

4. The method of claim 3, wherein the CRC generator polynomial comprises:

1+x⁵+x¹²+x¹⁶.

5. The method of claim 1, wherein checking for errors further comprises:

generating an error detection code based on the re-formed packet.

6. The method of claim 5, wherein checking for errors further comprises:

comparing the error detection code associated with the re-formed data with the extracted error detection code.

7. A network device, comprising:

input logic configured to;

receive data,

generate an error detection code for the received data,

divide the data into one or more cells,

insert the error detection code into one of the cells, and

forward the cells to an output of the network device; and

output logic configured to;

extract the error detection code from the one of the cells,

re-form the data from the one or more cells, and

check for data errors using the extracted error detection code.

8. The network device of claim 7, wherein the error detection code comprises a cyclic redundancy check (CRC) value.

9. The network device of claim 8, the input logic further configured to:

generate the CRC value using a CRC generator polynomial.

10. The network device of claim 9, wherein the CRC generator polynomial comprises:

1+x⁵+x¹²+x¹⁶.

11. The network device of claim 7, the output logic further configured to:

generate an error detection code based on the re-formed packet.

12. The network device of claim 11, the output logic further configured to:

compare the error detection code associated with the re-formed data with the extracted error detection code.

13. A method of processing data in a device, processing:

receiving data at an input of the device;

determining a first error code based on the data;

transferring the data through the network device to an output of the network device;

determining a second error code based on the transferred data; and

comparing the first and second error codes.

14. The method of claim 13, wherein the data comprises a packet.

15. The method of claim 13, further comprising:

dropping the data based on the comparing.

16. The method of claim 13, further comprising:

dividing the data into cells.

17. The method of claim 13, further comprising:

transferring the first error code with the data.

18. The method of claim 13, wherein the device comprises a router.

19. A system for detecting errors in a device, comprising:

a receiver configured to receive data at an input of the device;

a first error code generator configured to generate a first error code based on the data;

an element configured to transfer the data through the device;

a second error code generator configured to generate a second error code based on the transferred data; and

an error determining element configured to determine an error condition based on the first and second error codes.

20. The system of claim 19, further comprising:

a transmitter configured to transmit the transferred data based on the error condition.

21. The system of claim 19, further comprising:

a fragmenting element configured to divide the data into cells.

22. The system of claim 19, further comprising:

a data unit configured to transfer at least a portion of the data; and

a stuffing element configured to stuff the first error code into an area of the data unit.