Apparatus and method of maintaining two-byte IP identification fields in IP headers

• US 7,283,527 B2
• Filed: 02/27/2002
• Issued: 10/16/2007
• Est. Priority Date: 02/27/2002
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Venkatsubra, Venkat, Jain, Vinit, Brown, Deanna Lynn Quigg, Messing, Jeffrey Paul
• Primary Examiner(s): HSU, ALPUS
• Application Number:
  US10/087,939
• Publication Number:
  US 20030161312A1
• Time in Patent Office: 2,057 Days
• Field of Search: 370/392, 370/389, 370/474, 370/465, 370/252, 370/539, 370/470, 370/471, 370/395.5, 370/395.52, 370/469, 370/395, 370/395.53, 370/335, 370/342, 370/401, 370/472, 370/473, 370/486, 370/487, 370/489, 370/490, 370/522, 370/60.1, 370/60, 370/61, 370/85.1, 370/85.4, 370/85.13, 370/92, 370/93, 370/94.1, 380/255, 380/270, 707/501, 707/513, 707/102, 371/20.1, 371/3, 371/24, 709/213, 709/218, 709/203, 709/236, 715/744, 713/152, 455/4.1, 455/4.2, 455/6.11, 375/200, 345/700, 345/336, 345/333, 345/334
• US Class Current: 370/392
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/166 IP fragmentation; TCP segmentation
• CPC Class Codes: H04L 69/168 specially adapted for link layer protocols, e.g. asynchronous transfer mode [ATM], synchronous optical network [SONET] or point-to-point protocol [PPP]

Abstract

A method, system and apparatus for maintaining a two-byte identification field of IP headers when a Gigabit Ethernet is in use are provided. Since the IP identification field is of two bytes, there is a limited number of identification numbers that may be used. Due to the high data transfer rate of the Gigabit Ethernet, this number may be reached within one second. Hence, there may be a possibility that two or more packets may have the same identification number while in transit. In a representative embodiment, one identification number is used for packets that may not be fragmented; thus, freeing the rest of the numbers for packets that may be fragmented.

Claims

1. A method of maintaining a two-byte identification field of an Internet protocol (IP) header of a packet of data, the packet of data being transmitted over a network, the method comprising the steps of:

determining whether the packet of data is permitted to be fragmented before being transmitted over the network wherein an identification number can be used more than once within a particular time span;

using a unique identification number in the IP header of the packet of data if the packet of data is permitted to be fragmented, the unique identification number being a number that will not be used in the IP header of any other packet of data within the particular time span; and

using a non-unique identification number in the IP header of the packet of data if the packet of data is not permitted to be fragmented, the non-unique identification number being a number that is used in the IP header of all packets of data that are not permitted to be fragmented to facilitate using unique identification numbers in the network.

2. The method of claim 1 wherein a bit is set in the IP header to indicate whether the packet is permitted to be fragmented.

3. The method of claim 2 wherein the bit is set in a flag field of the IP header.

4. A computer readable medium encoded with a computer program product, when executed by a computer, for maintaining a two-byte identification field of an Internet protocol (IP) header of a packet of data, the packet of data being transmitted over a network, the computer program product comprising:

code means for determining whether the packet of data is permitted to be fragmented before being transmitted over the network wherein an identification number can be used more than once within a particular time span;

code means for using a unique identification number in the IP header of the packet of data if the packet of data is permitted to be fragmented, the unique identification number being a number that will not be used in the IP header of any other packet of data within the particular time span; and

code means for using a non-unique identification number in the IP header of the packet of data if the packet of data is not permitted to be fragmented, the non-unique identification number being a number that is used in the IP header of all packets of data that are not permitted to be fragmented to facilitate using unique identification numbers in the network.

5. The computer program product of claim 4 wherein a bit is set in the IP header to indicate whether the packet is permitted to be fragmented.

6. The computer program product of claim 5 wherein the bit is set in a flag field of the IP header.

7. An apparatus for maintaining a two-byte identification field of an Internet protocol (IP) header of a packet of data, the packet of data being transmitted over a network, the apparatus comprising:

means for determining whether the packet of data is permitted to be fragmented before being transmitted over the network wherein an identification number can be used more than once within a particular time span;

means for using a unique identification number in the IP header of the packet of data if the packet of data is permitted to be fragmented, the unique identification number being a number that will not be used in the IP header of any other packet of data within the particular time span; and

means for using a non-unique identification number in the IP header of the packet of data if the packet of data is not permitted to be fragmented, the non-unique identification number being a number that is used in the IP header of all packets of data that are not permitted to be fragmented to facilitate using unique identification numbers in the network.

8. The apparatus of claim 7 wherein a bit is set in the IP header to indicate whether the packet is permitted to be fragmented.

9. The apparatus of claim 8 wherein the bit is set in a flag field of the IP header.

10. A computer system for maintaining a two-byte identification field of an Internet protocol (IP) header of a packet of data, the packet of data being transmitted over a network, the computer system comprising:

at least one memory device for storing code data; and

at least one processor for processing the code data to determine whether the packet of data is permitted to be fragmented before being transmitted over the network wherein an identification number can be used more than once within a particular time span, to use a unique identification number in the IP header of the packet of data if the packet of data is permitted to be fragmented, the unique identification number being a number that will not be used in the IP header of any other packet of data within the particular time span, and to use a non-unique identification number in the IP header of the packet of data if the packet of data is not permitted to be fragmented, the non-unique identification number being a number that is used in the IP header of all packets of data that are not permitted to be fragmented to facilitate using unique identification numbers in the network.

11. The computer system of claim 10 wherein a bit is set in the IP header to indicate whether the packet is permitted to be fragmented.

12. The computer system of claim 11 wherein the bit is set in a flag field of the IP header.