US5815516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for producing transmission control protocol checksums using internet protocol fragmentation
Assignee: International Business Machines Corp
•
Filing: 1996-04-05
•
Granted: 1998-09-29
•
Expires: 2016-04-05
Abstract
Abstract An improved method and apparatus are provided for producing transmission control protocol (TCP) checksums using internet protocol (IP) fragmentation. A transmission control protocol module receives packet data to be transmitted and prepares a first internet protocol data fragment without a checksum for the received packet data. The first internet protocol data fragment is transmitted. Collecting checksum is performed during the transmission of the first internet protocol data fragment. Then an internet protocol header fragment including the collected checksum is transmitted.
Inventors
- 👤 Kenneth Dale Aaker
- 👤 Gary Scott Delp
- 👤 Lee Anton Sendelbach
- 👤 Albert Alfonse Slane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:27
CPC Classifications
H; H04; H04L; H04L69/00; H04L69/16; H04L69/161; H04L69/166; H04L9/00; H04L9/40; H04L69/22
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
185 words
A method for producing transmission control protocol (TCP) checksums using internet protocol (IP) fragmentation comprising the steps of: receiving packet data to be transmitted and preparing a first internet protocol data fragment without a checksum for the received packet data; said first internet protocol data fragment including an internet protocol header, and said internet protocol header having a fragment offset value equal to a set value for a transmission control protocol (TCP) header and having a total length value reduced by said set value; transmitting said first internet protocol data fragment to a receiving system and collecting checksum while transmitting said internet protocol data fragment; and after transmission of said first internet protocol data fragment, transmitting an internet protocol header fragment; said internet protocol header fragment including a modified internet protocol header and a transmission control protocol (TCP) header; said modified internet protocol header having a fragment offset value equal to zero and having a total length value equal to a total of said set value and a predetermined value for said internet protocol header; said transmission control protocol (TCP) header including said collected checksum.
Claim 2
Independent Claim
185 words
A method for producing transmission control protocol (TCP) checksums using internet protocol (IP) fragmentation comprising the steps of: receiving packet data to be transmitted and preparing a first internet protocol data fragment without a checksum for the received packet data; said first internet protocol data fragment including an internet protocol header, and said internet protocol header having a fragment offset value equal to a set value for a transmission control protocol (TCP) header and having a total length value reduced by said set value; transmitting said first internet protocol data fragment to a receiving system and collecting checksum while transmitting said internet protocol data fragment; and after transmission of said first internet protocol data fragment, transmitting an internet protocol header fragment; said internet protocol header fragment including a modified internet protocol header and a transmission control protocol (TCP) header; said modified internet protocol header having a fragment offset value equal to zero and having a total length value equal to a total of said set value and a predetermined value for said internet protocol header; said transmission control protocol (TCP) header including said collected checksum.
Claim 3
Dependent Claim
66 words
A method for producing transmission control protocol (TCP) checksums as recited in claim 1 wherein said internet protocol header and said modified internet protocol header includes fields providing identification, source, destination, and protocol, and wherein the step of preparing said first internet protocol data fragment includes the step of setting an identification value for the first internet protocol data fragment and the internet protocol header fragment.
Claim 4
Dependent Claim
39 words
A method for producing transmission control protocol (TCP) checksums as recited in claim 1 wherein the step of preparing said first internet protocol data fragment includes the step of setting a predefined IP flag field to indicate fragmentation allowed.
Claim 5
Dependent Claim
40 words
A method for producing transmission control protocol (TCP) checksums as recited in claim 1 wherein the step of preparing said first internet protocol data fragment includes the step of setting a predefined IP flag field to indicate a last fragment.
Claim 6
Dependent Claim
25 words
A method for producing transmission control protocol (TCP) checksums as recited in claim 1 further includes the step of preparing said internet protocol header fragment.
Claim 7
Dependent Claim
29 words
A method for producing transmission control protocol (TCP) checksums as recited in claim 5 further includes the steps of setting a predefined IP flag field to indicate fragmentation allowed.
Claim 8
Dependent Claim
31 words
A method for producing transmission control protocol (TCP) checksums as recited in claim 5 further includes the steps of setting a predefined IP flag field to indicate not a last fragment.
Claim 9
Dependent Claim
231 words
Apparatus for producing transmission control protocol (TCP) checksums using internet protocol (IP) fragmentation comprising: TCP means for receiving packet data to be transmitted and for preparing a first internet protocol data fragment without a checksum for the received packet data; said first internet protocol data fragment including an internet protocol header, and said internet protocol header having a fragment offset value equal to a set value for a transmission control protocol (TCP) header and having a total length value reduced by said set value; IP means responsive to said TCP means for transmitting said first internet protocol data fragment to a receiving system and for collecting checksum while transmitting said internet protocol data fragment; and said TCP means including means responsive to said first internet protocol data fragment transmitted by said IP means for preparing an internet protocol header fragment and said IP means including means responsive to said TCP means for transmitting said internet protocol header fragment after transmission of said first internet protocol data fragment; said internet protocol header fragment including a modified internet protocol header and a transmission control protocol (TCP) header; said modified internet protocol header having a fragment offset value equal to zero and having a total length value equal to a total of said set value and a predetermined value for said internet protocol header; said transmission control protocol (TCP) header including said collected checksum.
Claim 10
Dependent Claim
231 words
Apparatus for producing transmission control protocol (TCP) checksums using internet protocol (IP) fragmentation comprising: TCP means for receiving packet data to be transmitted and for preparing a first internet protocol data fragment without a checksum for the received packet data; said first internet protocol data fragment including an internet protocol header, and said internet protocol header having a fragment offset value equal to a set value for a transmission control protocol (TCP) header and having a total length value reduced by said set value; IP means responsive to said TCP means for transmitting said first internet protocol data fragment to a receiving system and for collecting checksum while transmitting said internet protocol data fragment; and said TCP means including means responsive to said first internet protocol data fragment transmitted by said IP means for preparing an internet protocol header fragment and said IP means including means responsive to said TCP means for transmitting said internet protocol header fragment after transmission of said first internet protocol data fragment; said internet protocol header fragment including a modified internet protocol header and a transmission control protocol (TCP) header; said modified internet protocol header having a fragment offset value equal to zero and having a total length value equal to a total of said set value and a predetermined value for said internet protocol header; said transmission control protocol (TCP) header including said collected checksum.
Claim 11
Dependent Claim
221 words
A computer program product for use in a computer system having a processor that produces transmission control protocol (TCP) checksums using internet protocol (IP) fragmentation, the computer program product comprising: a recording medium; means, recorded on the recording medium, for receiving packet data to be transmitted and preparing a first internet protocol data fragment without a checksum for the received packet data; said first internet protocol data fragment including an internet protocol header, and said internet protocol header having a fragment offset value equal to a set value for a transmission control protocol (TCP) header and having a total length value reduced by said set value; means, recorded on the recording medium, for transmitting said first internet protocol data fragment to a receiving system and collecting checksum while transmitting said internet protocol data fragment; and means, recorded on the recording medium, for transmitting an internet protocol header fragment after transmission of said first internet protocol data fragment; said internet protocol header fragment including a modified internet protocol header and a transmission control protocol (TCP) header; said modified internet protocol header having a fragment offset value equal to zero and having a total length value equal to a total of said set value and a predetermined value for said internet protocol header; said transmission control protocol (TCP) header including said collected checksum.
Claim 12
Dependent Claim
221 words
A computer program product for use in a computer system having a processor that produces transmission control protocol (TCP) checksums using internet protocol (IP) fragmentation, the computer program product comprising: a recording medium; means, recorded on the recording medium, for receiving packet data to be transmitted and preparing a first internet protocol data fragment without a checksum for the received packet data; said first internet protocol data fragment including an internet protocol header, and said internet protocol header having a fragment offset value equal to a set value for a transmission control protocol (TCP) header and having a total length value reduced by said set value; means, recorded on the recording medium, for transmitting said first internet protocol data fragment to a receiving system and collecting checksum while transmitting said internet protocol data fragment; and means, recorded on the recording medium, for transmitting an internet protocol header fragment after transmission of said first internet protocol data fragment; said internet protocol header fragment including a modified internet protocol header and a transmission control protocol (TCP) header; said modified internet protocol header having a fragment offset value equal to zero and having a total length value equal to a total of said set value and a predetermined value for said internet protocol header; said transmission control protocol (TCP) header including said collected checksum.
Claim 13
Dependent Claim
65 words
A computer program product as recited in claim 9 wherein said internet protocol header and said modified internet protocol header includes fields providing identification, source, destination, and protocol, and wherein said means, recorded on the recording medium, for preparing said first internet protocol data fragment includes means for setting an identification value for the first internet protocol data fragment and the internet protocol header fragment.
Claim 14
Dependent Claim
38 words
A computer program product as recited in claim 9 wherein said means, recorded on the recording medium, for preparing said first internet protocol data fragment includes means for setting a predefined IP flag field to indicate fragmentation allowed.
Claim 15
Dependent Claim
39 words
A computer program product as recited in claim 9 wherein said means, recorded on the recording medium, for preparing said first internet protocol data fragment includes means for setting a predefined IP flag field to indicate a last fragment.
Claim 16
Dependent Claim
24 words
A computer program product as recited in claim 9 further includes means, recorded on the recording medium, for preparing said internet protocol header fragment.
Claim 17
Dependent Claim
28 words
A computer program product as recited in claim 13 further includes means, recorded on the recording medium, for setting a predefined IP flag field to indicate fragmentation allowed.
Claim 18
Dependent Claim
30 words
A computer program product as recited in claim 13 further includes means, recorded on the recording medium, for setting a predefined IP flag field to indicate not a last fragment.
References Cited (Backward Citations)
US4493021A
Cited
US4639921A
Cited
US5058110A
Cited
US5500864A
Cited
US5430842A
Cited
US5522039A
Cited
US5444709A
Cited
US5541920A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-09-28 | 2002-03-30 | 2002-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-28 | 2006-03-30 | 2006-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-28 | 2010-03-30 | 2010-09-29 | $7700.00 | Window Closed / Lapsed |