Patent US6493318B1 successfully refreshed from Google Patents.
US6493318B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cost propagation switch protocols
Assignee: Hewlett Packard Enterprise Development LP
•
Filing: 1999-01-11
•
Granted: 2002-12-10
•
Expires: 2019-01-11
Abstract
Abstract A switch to switch protocol for network load balancing which exchanges cost information among all switches in a load balance domain. As compared to prior techniques, the protocol of the present invention updates all switches in the load balance domain periodically. All switches in the load balance domain are thereby assured of having consistent cost information regarding all switches in the load balance domain. Further, the protocol of the present invention reduces the volume of cost messaging traffic as exemplified by techniques which generate updates to the information any time a cost parameter of a switch changed. The preferred embodiment of he protocol of the present invention exchanges messages describing the switch latency for each switch in the load balance domain. A bit mask field in the transmitted cost packets indicates which switches have already received the cost information. Receipt of the same packet a second time by a switch which already received the cost packet is indicative of a loop in the network and the propagation of that packet is terminated.
Inventors
- 👤 Ballard C. Bare
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:05
CPC Classifications
H; H04; H04L; H04L45/00; H04L45/02; H04L45/026; H04L45/20; H04L45/66; H04L47/00; H04L47/10; H04L47/12; H04L47/125
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
107 words
A method operable within a plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches so as to propagate cost information among said plurality of network switches; and periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time so as to periodically update the cost information among said plurality of network switches instead of updating the cost information directly in response to any cost parameter change.
Claim 2
Independent Claim
107 words
A method operable within a plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches so as to propagate cost information among said plurality of network switches; and periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time so as to periodically update the cost information among said plurality of network switches instead of updating the cost information directly in response to any cost parameter change.
Claim 3
Dependent Claim
89 words
The method of claim 1 wherein the step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches.
Claim 4
Dependent Claim
44 words
The method of claim 2 wherein said cost information packets include a hop count field and wherein the method further comprises the step of: incrementing said hop count field in association with the step of transmitting and in association with the step of forwarding.
Claim 5
Dependent Claim
47 words
The method of claim 3 further comprising the steps of: comparing the value of said hop count field to a predetermined maximum value; and bypassing the step of forwarding in response to a determination that said value of said hop count field exceeds said predetermined maximum value.
Claim 6
Dependent Claim
54 words
The method of claim 2 further comprising the steps of: awaiting receipt of a cost information response packet from each of said other switches in response to transmission of said cost information packet; and retransmitting said cost information packet in response expiration of a timeout period without receipt of said cost information response packet.
Claim 7
Dependent Claim
118 words
The method of claim 5 wherein said cost information packets include a transmission retry count field and wherein the step of transmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous transmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous transmission of said cost information packet, and wherein the step of retransmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous retransmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous retransmission of said cost information packet.
Claim 8
Dependent Claim
49 words
The method of claim 6 further comprising the step of: comparing the value of said transmission retry count field to a predetermined maximum value; and bypassing the steps of resending in response to a determination that said value of said transmission retry count field exceeds said predetermined maximum value.
Claim 9
Dependent Claim
86 words
The method of claim 2 wherein said cost information packet includes a loop bit offset value associated with the transmitting switch of said cost information packet and wherein the step of transmitting includes the step of: storing the loop bit offset value associated with said first switch in said cost information packet prior to transmission thereof, and wherein the step of forwarding includes the step of: storing the loop bit offset value associated with said first switch in said cost information packet prior to forwarding thereof.
Claim 10
Dependent Claim
104 words
The method of claim 8 wherein said cost information packet includes a bit mask field having a bit corresponding to each possible loop bit offset value and wherein the step of transmitting includes the step of: setting the bit in said bit mask field corresponding to said loop bit offset value associated with said first switch in said cost information packet prior to transmission thereof, and wherein the step of forwarding includes the step of: setting the bit in said bit mask field corresponding to said loop bit offset value associated with said first switch in said cost information packet prior to forwarding thereof.
Claim 11
Dependent Claim
76 words
The method of claim 9 further comprising the steps of: determining that the bit in said bit mask field corresponding to said loop bit offset value associated with said first switch in the received cost information packet is set; and bypassing the step of forwarding in response to a determination that said bit in said bitmask corresponding to said loop bit offset value associated with said first switch in the received cost information packet is set.
Claim 12
Dependent Claim
33 words
The method of claim 10 further comprising the step of: recording loop information derived from said bit mask field of said received cost information packet in a memory associated with said first switch.
Claim 13
Dependent Claim
54 words
The method of claim 2 wherein the step of recording includes the step of: storing path information derived from said cost information packet and corresponding cost information derived from said cost information packet in a first location of a memory associated with said first switch in response to receipt of said cost information packets.
Claim 14
Dependent Claim
42 words
The method of claim 12 further comprising the step of: awaiting convergence of the step of propagating said cost information; and copying said path information and said corresponding cost information to a second location of said memory in response to said convergence.
Claim 15
Dependent Claim
28 words
The method of claim 13 wherein the step of awaiting convergence includes the step of: waiting for a predetermined period of time after initiation of the periodic propagation.
Claim 16
Dependent Claim
23 words
The method of claim 14 further comprising the step of: discarding said cost information packets received from said another switch after said convergence.
Claim 17
Dependent Claim
50 words
The method of claim 13 wherein each said cost information packet includes a sequence number indicative of the convergence period for which it was propagated and wherein the step of awaiting convergence includes the step of: using said sequence number to determine when convergence has occurred for said convergence period.
Claim 18
Independent Claim
127 words
A system including a plurality of network switches, each of said switches including a computer readable storage medium tangibly embodying a method operable within said plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches so as to propagate cost information among said plurality of network switches; and periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time so as to periodically update the cost information among said plurality of network switches instead of updating the cost information directly in response to any cost parameter change.
Claim 19
Independent Claim
127 words
A system including a plurality of network switches, each of said switches including a computer readable storage medium tangibly embodying a method operable within said plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches so as to propagate cost information among said plurality of network switches; and periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time so as to periodically update the cost information among said plurality of network switches instead of updating the cost information directly in response to any cost parameter change.
Claim 20
Dependent Claim
90 words
The system of claim 17 wherein the method step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches.
Claim 21
Dependent Claim
44 words
The system of claim 18 wherein said cost information packets include a hop count field and wherein the method further comprises the step of: incrementing said hop count field in association with the step of transmitting and in association with the step of forwarding.
Claim 22
Dependent Claim
50 words
The system of claim 19 wherein the method further comprises the steps of: comparing the value of said hop count field to a predetermined maximum value; and bypassing the step of forwarding in response to a determination that said value of said hop count field exceeds said predetermined maximum value.
Claim 23
Dependent Claim
57 words
The system of claim 18 wherein the method further comprises the steps of: awaiting receipt of a cost information response packet from each of said other switches in response to transmission of said cost information packet; and retransmitting said cost information packet in response expiration of a timeout period without receipt of said cost information response packet.
Claim 24
Dependent Claim
120 words
The system of claim 21 wherein said cost information packets include a transmission retry count field and wherein the method step of transmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous transmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous transmission of said cost information packet, and wherein the method step of retransmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous retransmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous retransmission of said cost information packet.
Claim 25
Dependent Claim
52 words
The system of claim 22 wherein the method further comprises the step of: comparing the value of said transmission retry count field to a predetermined maximum value; and bypassing the steps of resending in response to a determination that said value of said transmission retry count field exceeds said predetermined maximum value.
Claim 26
Dependent Claim
88 words
The system of claim 18 wherein said cost information packet includes a loop bit offset value associated with the transmitting switch of said cost information packet and wherein the method step of transmitting includes the step of: storing the loop bit offset value associated with said first switch in said cost information packet prior to transmission thereof, and wherein the method step of forwarding includes the step of: storing the loop bit offset value associated with said first switch in said cost information packet prior to forwarding thereof.
Claim 27
Dependent Claim
106 words
The system of claim 24 wherein said cost information packet includes a bit mask field having a bit corresponding to each possible loop bit offset value and wherein the method step of transmitting includes the step of: setting the bit in said bit mask field corresponding to said loop bit offset value associated with said first switch in said cost information packet prior to transmission thereof, and wherein the method step of forwarding includes the step of: setting the bit in said bit mask field corresponding to said loop bit offset value associated with said first switch in said cost information packet prior to forwarding thereof.
Claim 28
Dependent Claim
79 words
The system of claim 25 wherein the method further comprises the steps of: determining that the bit in said bit mask field corresponding to said loop bit offset value associated with said first switch in the received cost information packet is set; and bypassing the step of forwarding in response to a determination that said bit in said bitmask corresponding to said loop bit offset value associated with said first switch in the received cost information packet is set.
Claim 29
Dependent Claim
36 words
The system of claim 26 wherein the method further comprises the step of: recording loop information derived from said bit mask field of said received cost information packet in a memory associated with said first switch.
Claim 30
Dependent Claim
55 words
The system of claim 18 wherein the method step of recording includes the step of: storing path information derived from said cost information packet and corresponding cost information derived from said cost information packet in a first location of a memory associated with said first switch in response to receipt of said cost information packets.
Claim 31
Dependent Claim
45 words
The system of claim 28 wherein the method further comprises the step of: awaiting convergence of the step of propagating said cost information; and copying said path information and said corresponding cost information to a second location of said memory in response to said convergence.
Claim 32
Dependent Claim
29 words
The system of claim 29 wherein the method step of awaiting convergence includes the step of: waiting for a predetermined period of time after initiation of the periodic propagation.
Claim 33
Dependent Claim
26 words
The system of claim 30 wherein the method further comprises the step of: discarding said cost information packets received from said another switch after said convergence.
Claim 34
Dependent Claim
51 words
The system of claim 29 wherein each said cost information packet includes a sequence number indicative of the convergence period for which it was propagated and wherein the method step of awaiting convergence includes the step of: using said sequence number to determine when convergence has occurred for said convergence period.
Claim 35
Independent Claim
308 words
A method operable within a plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; awaiting receipt of a cost information response packet from each of said other switches in response to transmission of said cost information packet; and retransmitting said cost information packet in response to expiration of a timeout period without receipt of said cost information response packet; wherein the step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein said cost information packets include a transmission retry count field and, wherein the step of transmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous transmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous transmission of said cost information packet; and wherein the step of retransmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous retransmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous transmission of said cost information packet.
Claim 36
Independent Claim
308 words
A method operable within a plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; awaiting receipt of a cost information response packet from each of said other switches in response to transmission of said cost information packet; and retransmitting said cost information packet in response to expiration of a timeout period without receipt of said cost information response packet; wherein the step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein said cost information packets include a transmission retry count field and, wherein the step of transmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous transmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous transmission of said cost information packet; and wherein the step of retransmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous retransmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous transmission of said cost information packet.
Claim 37
Independent Claim
231 words
A method operable within a plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; wherein the step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein said cost information packet includes a loop bit offset value associated with the transmitting switch of said cost information packet and wherein the step of transmitting includes the step of storing the loop bit offset value associated with said first switch in said cost information packet prior to transmission thereof, and wherein the step of forwarding includes the step of storing the loop bit offset value associated with said first switch in said cost information packet prior to forwarding thereof.
Claim 38
Independent Claim
231 words
A method operable within a plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; wherein the step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein said cost information packet includes a loop bit offset value associated with the transmitting switch of said cost information packet and wherein the step of transmitting includes the step of storing the loop bit offset value associated with said first switch in said cost information packet prior to transmission thereof, and wherein the step of forwarding includes the step of storing the loop bit offset value associated with said first switch in said cost information packet prior to forwarding thereof.
Claim 39
Independent Claim
277 words
A method operable within a plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; awaiting convergence of the step of propagating said cost information; and copying said path information and said corresponding cost information to a second location of said memory in response to said convergence; wherein the step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein the step of recording includes the step of: storing path information derived from said cost information packet and corresponding cost information derived from said cost information packet in a first location of a memory associated with said first switch in response to receipt of said cost information packets; wherein each of said cost information packet includes a sequence number indicative of the convergence period for which it was propagated and wherein the step of awaiting convergence includes the step of using said sequence number to determine when convergence has occurred for said convergence period.
Claim 40
Independent Claim
277 words
A method operable within a plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; awaiting convergence of the step of propagating said cost information; and copying said path information and said corresponding cost information to a second location of said memory in response to said convergence; wherein the step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein the step of recording includes the step of: storing path information derived from said cost information packet and corresponding cost information derived from said cost information packet in a first location of a memory associated with said first switch in response to receipt of said cost information packets; wherein each of said cost information packet includes a sequence number indicative of the convergence period for which it was propagated and wherein the step of awaiting convergence includes the step of using said sequence number to determine when convergence has occurred for said convergence period.
Claim 41
Independent Claim
332 words
A system including a plurality of network switches, each of said switches including a computer readable storage medium tangibly embodying a method operable within said plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; and periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; awaiting receipt of a cost information response packet from each of said other switches in response to transmission of said cost information packet; and retransmitting said cost information packet in response to expiration of a timeout period without receipt of said cost information response packet; wherein the method step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein said cost information packets include a transmission retry count field and, wherein the method step of transmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous transmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous transmission of said cost information packet; and wherein the method step of retransmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous retransmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous transmission of said cost information packet.
Claim 42
Independent Claim
332 words
A system including a plurality of network switches, each of said switches including a computer readable storage medium tangibly embodying a method operable within said plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; and periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; awaiting receipt of a cost information response packet from each of said other switches in response to transmission of said cost information packet; and retransmitting said cost information packet in response to expiration of a timeout period without receipt of said cost information response packet; wherein the method step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein said cost information packets include a transmission retry count field and, wherein the method step of transmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous transmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous transmission of said cost information packet; and wherein the method step of retransmitting includes the steps of: incrementing said retry count field in response to sensing a failure of a previous retransmission of said cost information packet; and resending said cost information packet in response to sensing a failure of a previous transmission of said cost information packet.
Claim 43
Independent Claim
254 words
A system including a plurality of network switches, each of said switches including a computer readable storage medium tangibly embodying a method operable within said plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; and periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; wherein the method step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein said cost information packet includes a loop bit offset value associated with the transmitting switch of said cost information packet and wherein the method step of transmitting includes the step of storing the loop bit offset value associated with said first switch in said cost information packet prior to transmission thereof, and wherein the step of forwarding includes the step of storing the loop bit offset value associated with said first switch in said cost information packet prior to forwarding thereof.
Claim 44
Independent Claim
254 words
A system including a plurality of network switches, each of said switches including a computer readable storage medium tangibly embodying a method operable within said plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; and periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; wherein the method step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein said cost information packet includes a loop bit offset value associated with the transmitting switch of said cost information packet and wherein the method step of transmitting includes the step of storing the loop bit offset value associated with said first switch in said cost information packet prior to transmission thereof, and wherein the step of forwarding includes the step of storing the loop bit offset value associated with said first switch in said cost information packet prior to forwarding thereof.
Claim 45
Independent Claim
222 words
A system including a plurality of network switches, each of said switches including a computer readable storage medium tangibly embodying a method operable within said plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; and periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; wherein the method step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein the method step of recording includes the step of storing path information derived from said cost information packet and corresponding cost information derived from said cost information packet in a first location of a memory associated with said first switch in response to receipt of said cost information packets.
Claim 46
Independent Claim
222 words
A system including a plurality of network switches, each of said switches including a computer readable storage medium tangibly embodying a method operable within said plurality of network switches for exchanging cost information among said plurality of network switches, said method comprising the steps of: propagating cost information packets between a first switch of said plurality of network switches and other switches of said plurality of network switches; and periodically repeating the propagation of said cost information packets based upon expiration of a pre-determined period of time; wherein the method step of propagating includes the steps of: transmitting a cost information packet from a first switch of said plurality of network switches to other switches of said plurality of network switches; receiving, in said first switch, a cost propagation packet transmitted from another switch of said plurality of network switches; recording information derived from the received cost information packet in a memory associated with said first switch; and forwarding the received cost propagation packet from said first switch to said other switches; wherein the method step of recording includes the step of storing path information derived from said cost information packet and corresponding cost information derived from said cost information packet in a first location of a memory associated with said first switch in response to receipt of said cost information packets.
Claim 47
Dependent Claim
18 words
The method of claim 1 , wherein propagating of cost information packets is performed at Layer 2 .
Claim 48
Dependent Claim
18 words
The system of claim 17 , wherein propagating of cost information packets is performed at Layer 2 .
Claim 49
Dependent Claim
12 words
The method of claim 1 , wherein the cost information is dynamic.
Claim 50
Dependent Claim
12 words
The system of claim 17 , wherein the cost information is dynamic.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-12-09 | 2006-06-10 | 2006-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-12-09 | 2010-06-10 | 2010-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-12-09 | 2014-06-10 | 2014-12-10 | $7700.00 | Window Closed / Lapsed |