US6201791B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for measuring flow capacity of and determining the optimal window size of a communications network
Assignee: International Business Machines Corp
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Filing: 1997-10-29
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Granted: 2001-03-13
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Expires: 2017-10-29
Abstract
Abstract The idle capacity of a packet network channel is dynamically estimated by transmitting only a single window of test packets at whatever window size is presently in use on the channel and by measuring the time intervals between acknowledgments (the inter-acknowledgment time) of adjacent packets. This value is used, for example, to dynamically allocate the idle bandwidth to applications. Preferably, an average value for the inter-acknowledgment time interval is calculated from all of the acknowledgment intervals associated with the window of packets. The idle capacity of the channel is then calculated from the formula C=1/IAvg, where C is the idle capacity in packets per second and IAvg is the average acknowledgment time between packets. Additionally, the same parameters that are collected to calculate the idle capacity are used to calculate the optimal window size, also on a dynamic basis.
Inventors
- 👤 Redha M. Bournas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:55
CPC Classifications
H; H04; H04L; H04L47/00; H04L47/10; H04L47/28; H04L47/283; H04L43/00; H04L43/50; H04L47/11; H04L47/115
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
94 words
A method of estimating the idle capacity of a packet network channel between a network source node and a network destination node, comprising the steps at the source node of transmitting one or more test packets to the destination node via the channel, where the number of test packets approximately equals the window size presently in use on the channel, determining from the test packet acknowledgments that are returned to the source node a value I representing the average time interval between acknowledgments, and calculating the estimated idle channel capacity from the formula C=1/I.
Claim 2
Independent Claim
94 words
A method of estimating the idle capacity of a packet network channel between a network source node and a network destination node, comprising the steps at the source node of transmitting one or more test packets to the destination node via the channel, where the number of test packets approximately equals the window size presently in use on the channel, determining from the test packet acknowledgments that are returned to the source node a value I representing the average time interval between acknowledgments, and calculating the estimated idle channel capacity from the formula C=1/I.
Claim 3
Dependent Claim
60 words
The method of claim 1 further comprising the steps of determining a value RTT representing the round trip time of test packet transmission and receipt of the corresponding acknowledgment, and calculating from the round trip time the estimated optimal window size of the channel from the formula N opt =RTT*C, where N opt is the estimated channel optimal window size.
Claim 4
Dependent Claim
46 words
The method of claim 2 wherein the step of determining the value RTT further comprises the step of calculating an average value RTT Avg from the round trip time of each of the test packets and using RTT Avg to calculate the estimated optimal window size.
Claim 5
Dependent Claim
36 words
The method of claim 1 wherein the step of transmitting the test packets further comprises the step of delaying the transmission of each of a group of successive test packets by a selected amount of time.
Claim 6
Dependent Claim
33 words
The method of claim 1 or claim 2 or claim 3 or claim 4 further comprising the step of allocating channel bandwidth to applications based on the calculated estimate of idle channel capacity.
Claim 7
Dependent Claim
31 words
The method of claim 2 or claim 3 further comprising the step of adjusting the window size used on the channel based on the calculated estimate of the optimal window size.
Claim 8
Dependent Claim
48 words
The method of claim 2 or claim 3 further comprising the step of periodically repeating the transmission of test packets and the calculation of the estimated idle channel capacity using the last calculated estimate of optimal window size to determine the number of test packets for each iteration.
Claim 9
Dependent Claim
96 words
Apparatus at a packet network source node for estimating the idle capacity of a packet network channel between the source node and a network destination node, comprising means for transmitting one or more test packets to the destination node via the channel, where the number of test packets equals the window size presently in use on the channel, means for determining from the test packet acknowledgments that are returned to the source node a value I representing the average time interval between acknowledgments, and means for calculating the estimated idle channel capacity from the formula C=1/I.
Claim 10
Dependent Claim
96 words
Apparatus at a packet network source node for estimating the idle capacity of a packet network channel between the source node and a network destination node, comprising means for transmitting one or more test packets to the destination node via the channel, where the number of test packets equals the window size presently in use on the channel, means for determining from the test packet acknowledgments that are returned to the source node a value I representing the average time interval between acknowledgments, and means for calculating the estimated idle channel capacity from the formula C=1/I.
Claim 11
Dependent Claim
61 words
The apparatus of claim 8 further comprising means for determining a value RTT representing the round trip time of test packet transmission and receipt of the corresponding acknowledgment, and means for calculating from the round trip time the estimated optimal window size of the channel from the formula N opt =RTT*C, where N opt is the estimated channel optimal window size.
Claim 12
Dependent Claim
47 words
The apparatus of claim 9 wherein the means for determining the value RTT further comprises means for calculating an average value RTT Avg from the round trip time of each of the test packets and means for calculating the estimated optimal window size from RTT Avg .
Claim 13
Dependent Claim
35 words
The apparatus of claim 8 wherein the means for transmitting the test packets further comprises means for delaying the transmission of each of a group of successive test packets by a selected amount of time.
Claim 14
Dependent Claim
32 words
The apparatus of claim 8 or claim 9 or claim 10 or claim 11 further comprising means for allocating channel bandwidth to applications based on the calculated estimate of idle channel capacity.
Claim 15
Dependent Claim
30 words
The apparatus of claim 9 or claim 10 further comprising means for adjusting the window size used on the channel based on the calculated estimate of the optimal window size.
Claim 16
Dependent Claim
47 words
The apparatus of claim 9 or claim 10 further comprising means for periodically repeating the transmission of test packets and the calculation of the estimated idle channel capacity using the last calculated estimate of optimal window size to determine the number of test packets for each iteration.
Claim 17
Dependent Claim
119 words
A media for storing software code, which code when loaded and executed on a computer at a network source node is capable of controlling the source node to perform a method of estimating the idle capacity of a packet network channel between the source node and a network destination node, the method comprising the steps of transmitting one or more test packets to the destination node via the channel, where the number of test packets equals the window size presently in use on the channel, determining from the test packet acknowledgments that are returned to the source node a value I representing the average time interval between acknowledgments, and calculating the estimated idle channel capacity from the formula C=1/I.
Claim 18
Dependent Claim
119 words
A media for storing software code, which code when loaded and executed on a computer at a network source node is capable of controlling the source node to perform a method of estimating the idle capacity of a packet network channel between the source node and a network destination node, the method comprising the steps of transmitting one or more test packets to the destination node via the channel, where the number of test packets equals the window size presently in use on the channel, determining from the test packet acknowledgments that are returned to the source node a value I representing the average time interval between acknowledgments, and calculating the estimated idle channel capacity from the formula C=1/I.
Claim 19
Dependent Claim
63 words
The media of claim 15 wherein the method further comprises the steps of determining a value RTT representing the round trip time of test packet transmission and receipt of the corresponding acknowledgment, and calculating from the round trip time the estimated optimal window size of the channel from the formula N opt =RTT*C, where N opt is the estimated channel optimal window size.
Claim 20
Dependent Claim
47 words
The media of claim 16 wherein the method step of determining the value RTT further comprises the step of calculating an average value RTT Avg from the round trip time of each of the test packets and using RTT Avg to calculate the estimated optimal window size.
Claim 21
Dependent Claim
37 words
The media of claim 15 wherein the method step of transmitting the test packets further comprises the step of delaying the transmission of each of a group of successive test packets by a selected amount of time.
Claim 22
Dependent Claim
35 words
The media of claim 15 claim 16 or claim 17 or claim 18 wherein the method further comprises the step of allocating channel bandwidth to applications based on the calculated estimate of idle channel capacity.
Claim 23
Dependent Claim
34 words
The media of claim 16 or claim 17 wherein the method further comprises the step of adjusting the window size used on the channel based on the calculated estimate of the optimal window size.
Claim 24
Dependent Claim
48 words
The media of claim 16 or claim 17 wherein the method further comprises periodically repeating the transmission of test packets and the calculation of the estimated idle channel capacity using the last calculated estimate of optimal window size to determine the number of test packets for each iteration.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-12 | 2004-09-11 | 2005-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-12 | 2008-09-11 | 2009-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-12 | 2012-09-11 | 2013-03-13 | $7700.00 | Window Closed / Lapsed |