US20020004843A1
Expired / Lapsed
US
⏱️ 0.0 years remaining
System, device, and method for bypassing network changes in a routed communication network
Assignee: Nortel Networks Ltd
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Filing: 2000-12-21
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Granted: —
•
Expires: 2020-12-21
Abstract
Abstract A system, device, and method for bypassing network changes in a communication network pre-computes recovery paths to protect various primary paths. A fast detection mechanism is preferably used to detect network changes quickly, and communications are switched over from the primary paths to the recovery paths in order to bypass network changes. Forwarding tables are preferably frozen as new primary paths are computed, and communications are switched over from the recovery paths to the new primary paths in a coordinated manner in order to avoid temporary loops and invalid routes. New recovery paths are computed to protect the new primary paths.
Inventors
- 👤 Loa Andersson
- 👤 Elwyn Davies
- 👤 Tove Madsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:34
CPC Classifications
H; H04; H04L; H04L45/00; H04L45/28; H04L45/22; H04L45/50
Claims Analysis
Total Claims: 106
Claim 1
Independent Claim
64 words
1 . A method for bypassing a network change by a node in a communication network, the method comprising: pre-determining a recovery path for bypassing a network change that affects communications over a primary path; detecting the network change that affects communications over the primary path; and switching communications from the primary path to the recovery path in order to bypass the network change.
Claim 2
Dependent Claim
64 words
1 . A method for bypassing a network change by a node in a communication network, the method comprising: pre-determining a recovery path for bypassing a network change that affects communications over a primary path; detecting the network change that affects communications over the primary path; and switching communications from the primary path to the recovery path in order to bypass the network change.
Claim 3
Dependent Claim
33 words
2 . The method of claim 1 , wherein pre-determining the recovery path for bypassing the network change comprises: establishing as the recovery path a label switched path that bypasses the network change.
Claim 4
Dependent Claim
40 words
3 . The method of claim 1 , wherein pre-determining the recovery path for bypassing the network change comprises: logically introducing the network change into a routing database; and determining the recovery path based upon a pre-determined path determination scheme.
Claim 5
Dependent Claim
18 words
4 . The method of claim 3 , wherein the pre-determined path determination scheme comprises a shortest-path-first computation.
Claim 6
Dependent Claim
27 words
5 . The method of claim 1 , wherein pre-determining the recovery path for bypassing the network change comprises: installing the recovery path in a forwarding table.
Claim 7
Dependent Claim
31 words
6 . The method of claim 1 , wherein detecting the network change that affects communications over the primary path comprises: using a fast liveness protocol to detect the network change.
Claim 8
Dependent Claim
16 words
7 . The method of claim 1 , wherein the network change comprises a link failure.
Claim 9
Dependent Claim
16 words
8 . The method of claim 1 , wherein the network change comprises a node failure.
Claim 10
Dependent Claim
16 words
9 . The method of claim 1 , wherein the network change comprises a routing change.
Claim 11
Dependent Claim
31 words
10 . The method of claim 1 , wherein switching communications from the primary path to the recovery path in order to bypass the network change comprises: activating the recovery path.
Claim 12
Dependent Claim
22 words
11 . The method of claim 10 , wherein activating the recovery path comprises: removing the primary path from a forwarding table.
Claim 13
Dependent Claim
22 words
12 . The method of claim 10 , wherein activating the recovery path comprises: blocking the primary path in a forwarding table.
Claim 14
Dependent Claim
31 words
13 . The method of claim 10 , wherein activating the recovery path comprises: marking the recovery path as a higher priority path than the primary path in a forwarding table.
Claim 15
Dependent Claim
38 words
14 . The method of claim 1 , wherein switching communications from the primary path to the recovery path in order to bypass the network change comprises: forwarding all communications from the primary path over the recovery path.
Claim 16
Dependent Claim
44 words
15 . The method of claim 1 , wherein switching communications from the primary path to the recovery path in order to bypass the network change comprises: forwarding some communications from the primary path over the recovery path based upon a predetermined priority scheme.
Claim 17
Dependent Claim
19 words
16 . The method of claim 15 , wherein the predetermined priority scheme comprises an IP Differentiated Services scheme.
Claim 18
Dependent Claim
15 words
17 . The method of claim 1 , further comprising: determining a new primary path.
Claim 19
Dependent Claim
29 words
18 . The method of claim 17 , wherein determining the new primary path comprises: receiving routing information; and computing the new primary path based upon the routing information.
Claim 20
Dependent Claim
15 words
19 . The method of claim 17 , further comprising: activating the new primary path.
Claim 21
Dependent Claim
27 words
20 . The method of claim 19 , further comprising: switching communications from the recovery path to the new primary path after activating the new primary path.
Claim 22
Dependent Claim
65 words
21 . The method of claim 19 , wherein determining the new primary path and activating the new primary path comprise: freezing a forwarding table after switching communications from the primary path to the recovery path; computing the new primary path while the forwarding table is frozen; and coordinating activation of the new primary path with at least one other node in the communication network.
Claim 23
Dependent Claim
39 words
22 . The method of claim 21 , wherein coordinating activation of the new primary path with at least one other node in the communication network comprises: using a timer to determine when to activate the new primary path.
Claim 24
Dependent Claim
41 words
23 . The method of claim 21 , wherein coordinating activation of the new primary path with at least one other node in the communication network comprises: using a predetermined diffusion mechanism to determine when to activate the new primary path.
Claim 25
Dependent Claim
48 words
24 . The method of claim 21 , wherein coordinating activation of the new primary path with at least one other node in the communication network comprises: receiving a signal from a master node; and activating the new primary path upon receiving the signal from the master node.
Claim 26
Dependent Claim
68 words
25 . The method of claim 21 , wherein coordinating activation of the new primary path with at least one other node in the communication network comprises: receiving signals from a number of slave nodes; determining that the number of slave nodes have completed computing new primary paths; and activating the new primary path upon determining that the number of slave node have completed computing new primary paths.
Claim 27
Dependent Claim
19 words
26 . The method of claim 25 , further comprising: sending a signal to the number of slave nodes.
Claim 28
Dependent Claim
21 words
27 . The method of claim 17 , further comprising: computing a new recovery path to protect the new primary path.
Claim 29
Dependent Claim
21 words
28 . The method of claim 19 , further comprising: computing a new recovery path after activating the new primary path.
Claim 30
Dependent Claim
77 words
29 . A device for bypassing a network change in a communication network, the device comprising: recovery path logic operably coupled to pre-determine a recovery path for bypassing a network change that affects communications over a primary path; detection logic operably coupled to detect the network change that affects communications over the primary path; and switching logic operably coupled to switch communications from the primary path to the recovery path in order to bypass the network change.
Claim 31
Dependent Claim
77 words
29 . A device for bypassing a network change in a communication network, the device comprising: recovery path logic operably coupled to pre-determine a recovery path for bypassing a network change that affects communications over a primary path; detection logic operably coupled to detect the network change that affects communications over the primary path; and switching logic operably coupled to switch communications from the primary path to the recovery path in order to bypass the network change.
Claim 32
Dependent Claim
31 words
30 . The device of claim 29 , wherein the recovery path logic is operably coupled to establish as the recovery path a label switched path that bypasses the network change.
Claim 33
Dependent Claim
38 words
31 . The device of claim 29 , wherein the recovery path logic is operably coupled to logically introduce the network change into a routing database and determine the recovery path based upon a pre-determined path determination scheme.
Claim 34
Dependent Claim
18 words
32 . The device of claim 31 , wherein the pre-determined path determination scheme comprises a shortest-path-first computation.
Claim 35
Dependent Claim
25 words
33 . The device of claim 29 , wherein the recovery path logic is operably coupled to install the recovery path in a forwarding table.
Claim 36
Dependent Claim
26 words
34 . The device of claim 29 , wherein the detection logic is operably coupled to use a fast liveness protocol to detect the network change.
Claim 37
Dependent Claim
16 words
35 . The device of claim 29 , wherein the network change comprises a link failure.
Claim 38
Dependent Claim
16 words
36 . The device of claim 29 , wherein the network change comprises a node failure.
Claim 39
Dependent Claim
16 words
37 . The device of claim 29 , wherein the network change comprises a routing change.
Claim 40
Dependent Claim
33 words
38 . The device of claim 29 , wherein the switching logic is operably coupled to activate the recovery path in order to switch communications from the primary path to the recovery path.
Claim 41
Dependent Claim
31 words
39 . The device of claim 38 , wherein the switching logic is operably coupled to remove the primary path from a forwarding table in order to activate the recovery path.
Claim 42
Dependent Claim
31 words
40 . The device of claim 38 , wherein the switching logic is operably coupled to block the primary path in a forwarding table in order to activate the recovery path.
Claim 43
Dependent Claim
40 words
41 . The device of claim 38 , wherein the switching logic is operably coupled to mark the recovery path as a higher priority path than the primary path in a forwarding table in order to activate the recovery path.
Claim 44
Dependent Claim
27 words
42 . The device of claim 29 , wherein the switching logic is operably coupled to forward all communications from the primary path over the recovery path.
Claim 45
Dependent Claim
33 words
43 . The device of claim 29 , wherein the switching logic is operably coupled to forward some communications from the primary path over the recovery path based upon a predetermined priority scheme.
Claim 46
Dependent Claim
19 words
44 . The device of claim 43 , wherein the predetermined priority scheme comprises an IP Differentiated Services scheme.
Claim 47
Dependent Claim
20 words
45 . The device of claim 29 , further comprising: reconvergence logic operably coupled to determine a new primary path.
Claim 48
Dependent Claim
30 words
46 . The device of claim 45 , wherein the reconvergence logic is operably coupled to receive routing information and compute the new primary path based upon the routing information.
Claim 49
Dependent Claim
21 words
47 . The device of claim 45 , wherein the reconvergence logic is operably coupled to activate the new primary path.
Claim 50
Dependent Claim
34 words
48 . The device of claim 47 , wherein the switching logic is operably coupled to switch communications from the recovery path to the new primary path upon activation of the new primary path.
Claim 51
Dependent Claim
45 words
49 . The device of claim 47 , wherein the reconvergence logic is operably coupled to freeze a forwarding table during computation of the new primary path and coordinate activation of the new primary path with at least one other node in the communication network.
Claim 52
Dependent Claim
28 words
50 . The device of claim 49 , wherein the reconvergence logic is operably coupled to use a timer to determine when to activate the new primary path.
Claim 53
Dependent Claim
30 words
51 . The device of claim 49 , wherein the reconvergence logic is operably coupled to use a predetermined diffusion mechanism to determine when to activate the new primary path.
Claim 54
Dependent Claim
37 words
52 . The device of claim 49 , wherein the reconvergence logic is operably coupled to receive a signal from a master node and activate the new primary path upon receiving the signal from the master node.
Claim 55
Dependent Claim
45 words
53 . The device of claim 49 , wherein the reconvergence logic is operably coupled to activate the new primary path upon determining that a number of slave nodes have completed computing new primary paths based upon signals received from the number of slave nodes.
Claim 56
Dependent Claim
39 words
54 . The device of claim 53 , wherein the reconvergence logic is operably coupled to send a signal to the number of slave nodes upon determining that the number of slave nodes have completed computing new primary paths.
Claim 57
Dependent Claim
27 words
55 . The device of claim 45 , wherein the recovery logic is operably coupled to compute a new recovery path to protect the new primary path.
Claim 58
Dependent Claim
28 words
56 . The device of claim 47 , wherein the recovery logic is operably coupled to compute a new recovery path after activation of the new primary path.
Claim 59
Dependent Claim
81 words
57 . A computer program for programming a computer system to bypass a network change in a communication network, the computer program comprising: recovery path logic programmed to pre-determine a recovery path for bypassing a network change that affects communications over a primary path; detection logic programmed to detect the network change that affects communications over the primary path; and switching logic programmed to switch communications from the primary path to the recovery path in order to bypass the network change.
Claim 60
Dependent Claim
81 words
57 . A computer program for programming a computer system to bypass a network change in a communication network, the computer program comprising: recovery path logic programmed to pre-determine a recovery path for bypassing a network change that affects communications over a primary path; detection logic programmed to detect the network change that affects communications over the primary path; and switching logic programmed to switch communications from the primary path to the recovery path in order to bypass the network change.
Claim 61
Dependent Claim
31 words
58 . The computer program of claim 57 , wherein the recovery path logic is programmed to establish as the recovery path a label switched path that bypasses the network change.
Claim 62
Dependent Claim
38 words
59 . The computer program of claim 57 , wherein the recovery path logic is programmed to logically introduce the network change into a routing database and determine the recovery path based upon a pre-determined path determination scheme.
Claim 63
Dependent Claim
19 words
60 . The computer program of claim 59 , wherein the predetermined path determination scheme comprises a shortest-path-first computation.
Claim 64
Dependent Claim
25 words
61 . The computer program of claim 57 , wherein the recovery path logic is programmed to install the recovery path in a forwarding table.
Claim 65
Dependent Claim
26 words
62 . The computer program of claim 57 , wherein the detection logic is programmed to use a fast liveness protocol to detect the network change.
Claim 66
Dependent Claim
17 words
63 . The computer program of claim 57 , wherein the network change comprises a link failure.
Claim 67
Dependent Claim
17 words
64 . The computer program of claim 57 , wherein the network change comprises a node failure.
Claim 68
Dependent Claim
17 words
65 . The computer program of claim 57 , wherein the network change comprises a routing change.
Claim 69
Dependent Claim
33 words
66 . The computer program of claim 57 , wherein the switching logic is programmed to activate the recovery path in order to switch communications from the primary path to the recovery path.
Claim 70
Dependent Claim
31 words
67 . The computer program of claim 66 , wherein the switching logic is programmed to remove the primary path from a forwarding table in order to activate the recovery path.
Claim 71
Dependent Claim
31 words
68 . The computer program of claim 66 , wherein the switching logic is programmed to block the primary path in a forwarding table in order to activate the recovery path.
Claim 72
Dependent Claim
40 words
69 . The computer program of claim 66 , wherein the switching logic is programmed to mark the recovery path as a higher priority path than the primary path in a forwarding table in order to activate the recovery path.
Claim 73
Dependent Claim
27 words
70 . The computer program of claim 57 , wherein the switching logic is programmed to forward all communications from the primary path over the recovery path.
Claim 74
Dependent Claim
33 words
71 . The computer program of claim 57 , wherein the switching logic is programmed to forward some communications from the primary path over the recovery path based upon a predetermined priority scheme.
Claim 75
Dependent Claim
20 words
72 . The computer program of claim 71 , wherein the predetermined priority scheme comprises an IP Differentiated Services scheme.
Claim 76
Dependent Claim
20 words
73 . The computer program of claim 57 , further comprising: reconvergence logic programmed to determine a new primary path.
Claim 77
Dependent Claim
30 words
74 . The computer program of claim 73 , wherein the reconvergence logic is programmed to receive routing information and compute the new primary path based upon the routing information.
Claim 78
Dependent Claim
21 words
75 . The computer program of claim 73 , wherein the reconvergence logic is programmed to activate the new primary path.
Claim 79
Dependent Claim
34 words
76 . The computer program of claim 75 , wherein the switching logic is programmed to switch communications from the recovery path to the new primary path upon activation of the new primary path.
Claim 80
Dependent Claim
45 words
77 . The computer program of claim 75 , wherein the reconvergence logic is programmed to freeze a forwarding table during computation of the new primary path and coordinate activation of the new primary path with at least one other node in the communication network.
Claim 81
Dependent Claim
28 words
78 . The computer program of claim 77 , wherein the reconvergence logic is programmed to use a timer to determine when to activate the new primary path.
Claim 82
Dependent Claim
30 words
79 . The computer program of claim 77 , wherein the reconvergence logic is programmed to use a predetermined diffusion mechanism to determine when to activate the new primary path.
Claim 83
Dependent Claim
37 words
80 . The computer program of claim 77 , wherein the reconvergence logic is programmed to receive a signal from a master node and activate the new primary path upon receiving the signal from the master node.
Claim 84
Dependent Claim
45 words
81 . The computer program of claim 77 , wherein the reconvergence logic is programmed to activate the new primary path upon determining that a number of slave nodes have completed computing new primary paths based upon signals received from the number of slave nodes.
Claim 85
Dependent Claim
39 words
82 . The computer program of claim 81 , wherein the reconvergence logic is programmed to send a signal to the number of slave nodes upon determining that the number of slave nodes have completed computing new primary paths.
Claim 86
Dependent Claim
27 words
83 . The computer program of claim 73 , wherein the recovery logic is programmed to compute a new recovery path to protect the new primary path.
Claim 87
Dependent Claim
28 words
84 . The computer program of claim 75 , wherein the recovery logic is programmed to compute a new recovery path after activation of the new primary path.
Claim 88
Dependent Claim
14 words
85 . The computer program of claim 57 embodied in a computer readable medium.
Claim 89
Dependent Claim
13 words
86 . The computer program of claim 57 embodied in a data signal.
Claim 90
Dependent Claim
31 words
87 . A communication system comprising a plurality of interconnected communication nodes, wherein primary paths are established for forwarding information and recovery paths are pre-computed for bypassing potential primary path failures.
Claim 91
Dependent Claim
31 words
87 . A communication system comprising a plurality of interconnected communication nodes, wherein primary paths are established for forwarding information and recovery paths are pre-computed for bypassing potential primary path failures.
Claim 92
Dependent Claim
28 words
88 . The communication system of claim 87 , wherein communications are switched from a primary path to a recovery path in order to bypass a network change.
Claim 93
Dependent Claim
40 words
89 . The communication system of claim 88 , wherein new primary paths are determined after communications are switched from the primary path to the recovery path, and communications are switched from the recovery path to a new primary path.
Claim 94
Dependent Claim
22 words
90 . The communication system of claim 89 , wherein each communication node freezes a forwarding table before determining new primary paths.
Claim 95
Dependent Claim
33 words
91 . The communication system of claim 89 , wherein new recovery paths for protecting the new primary paths are computed before switching communications from the recovery path to the new primary path.
Claim 96
Dependent Claim
33 words
92 . The communication system of claim 89 , wherein new recovery paths for protecting the new primary paths are computer after switching communications from the recovery path to the new primary path.
Claim 97
Dependent Claim
49 words
93 . A method for reconverging routes in a communication network, the method comprising: determining that a route change is needed; freezing forwarding tables so that a predetermined set of routes is used during reconvergence; and reconverging on a new set of routes while the forwarding tables are frozen.
Claim 98
Dependent Claim
49 words
93 . A method for reconverging routes in a communication network, the method comprising: determining that a route change is needed; freezing forwarding tables so that a predetermined set of routes is used during reconvergence; and reconverging on a new set of routes while the forwarding tables are frozen.
Claim 99
Dependent Claim
20 words
94 . The method of claim 93 , further comprising: activating the new set of routes in a coordinated manner.
Claim 100
Dependent Claim
59 words
95 . The method of claim 94 , wherein activating the new set of routes in a coordinated manner comprises: starting a timer by each of a number of nodes in the communication network upon determining that reconvergence is needed; and activating the new set of routes by each of the number of nodes upon expiration of the timer.
Claim 101
Dependent Claim
58 words
96 . The method of claim 94 , wherein activating the new set of routes in a coordinated manner comprises: using a predetermined diffusion mechanism by each of the number of nodes to determine when reconvergence is complete; and activating the new set of routes by each of the number of nodes upon determining that reconvergence is complete.
Claim 102
Dependent Claim
85 words
97 . The method of claim 94 , wherein activating the new set of routes in a coordinated manner comprises: designating one of the number of nodes as a master node and designating the remaining nodes as slave nodes; sending a first signal by each of the slave nodes to the master node upon reconverging on the new set of routes; and sending a second signal by the master node to the slave nodes upon receiving the first signal from each of the slave nodes.
Claim 103
Dependent Claim
67 words
98 . A use of a bypass mechanism for bypassing a network change in a communication network, the use comprising: using the bypass mechanism to pre-compute a recovery path for bypassing a network change affecting communication over a primary path, detect the network change affecting communication over the primary path, and switch communications from the primary path to the pre-computed recovery path upon detecting said network change.
Claim 104
Dependent Claim
67 words
98 . A use of a bypass mechanism for bypassing a network change in a communication network, the use comprising: using the bypass mechanism to pre-compute a recovery path for bypassing a network change affecting communication over a primary path, detect the network change affecting communication over the primary path, and switch communications from the primary path to the pre-computed recovery path upon detecting said network change.
Claim 105
Dependent Claim
50 words
99 . The use of claim 98 , further comprising: using the bypass mechanism to compute a new primary path after switching communications from the primary path to the pre-computed recovery path; and using the bypass mechanism to switch communications from the pre-computed recovery path to the new primary path.
Claim 106
Dependent Claim
32 words
100 . The use of claim 99 , further comprising: using the bypass mechanism to compute a new recovery path for bypassing a network change affecting communication over the new primary path.
References Cited (Backward Citations)
US5941955A
Cited
US5933422A
Cited
US6512740B1
Cited
US6148410A
Cited
US6314093B1
Cited
US6625659B1
Cited
US6363053B1
Cited
US6530032B1
Cited
US6757242B1
Cited
US6392989B1
Cited
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