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US7477642B2
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MPLS traffic engineering for point-to-multipoint label switched paths
Assignee: Ericsson AB
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Filing: 2005-01-27
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Granted: 2009-01-13
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Expires: 2025-01-27
Abstract
Abstract A method and apparatus for providing point-to-multipoint label switch paths (LSPs) in a Multi-Protocol Label Switching (MPLS) network is described. In one embodiment, a point-to-multipoint LSP is built in a MPLS network by using Resource Reservation Protocol Traffic Engineering (RSVP-TE) to signal the point-to-multipoint LSP as separate point-to-point LSPs and to merge the separate point-to-point LSPs into the point-to-multipoint LSP.
Inventors
- 👤 Rahul Aggarwal
- 👤 George Apostolopoulos
- 👤 Liming Wei
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:24
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/66; H04H; H04H20/00; H04H20/16; H04L45/00; H04L45/16; H04L45/48; H04L45/50; H04L45/507; H04L61/00; H04L61/09; H04L61/25; H04L61/2503; H04L61/2592
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
71 words
A method comprising: building a point-to-multipoint label switch path (LSP) in a multi-protocol label switching (MPLS) network by using Resource Reservation Protocol Traffic Engineering (RSVP-TE) to signal the point-to-multipoint LSP as a plurality of separate point-to-point LSPs associated with a plurality of receivers participating in a session without transmitting a representation of the topology of the point-to-multipoint LSP and to merge the plurality of separate point-to-point LSPs into the point-to-multipoint LSP.
Claim 2
Independent Claim
71 words
A method comprising: building a point-to-multipoint label switch path (LSP) in a multi-protocol label switching (MPLS) network by using Resource Reservation Protocol Traffic Engineering (RSVP-TE) to signal the point-to-multipoint LSP as a plurality of separate point-to-point LSPs associated with a plurality of receivers participating in a session without transmitting a representation of the topology of the point-to-multipoint LSP and to merge the plurality of separate point-to-point LSPs into the point-to-multipoint LSP.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein the signaling of the point-to-multipoint LSP is initiated by an edge router attached to a source.
Claim 4
Dependent Claim
23 words
The method of claim 1 wherein each of the plurality of separate point-to-point LSPs is associated with an identifier of the point-to-multipoint LSP.
Claim 5
Dependent Claim
33 words
The method of claim 3 wherein the identifier of the point-to-multipoint LSP is provided by a session object included in each message exchanged between nodes identified in the plurality of separate point-to-point LSPs.
Claim 6
Dependent Claim
15 words
The method of claim 4 wherein the plurality of separate point-to-point LSPs share network resources.
Claim 7
Independent Claim
103 words
A method in a network device comprising: identifying a plurality of receivers requesting to receive data from a source in a session; determining that the plurality of receivers do not belong to any existing point-to-multipoint label switch path (LSP); computing a plurality of point-to-point LSPs for the plurality of receivers; sending a plurality of PATH messages, each of the plurality of PATH messages pertaining to a corresponding one of the plurality of point-to-point LSPs, wherein each of the PATH messages does not include a representation of the topology of a point-to-multipoint LSP; and merging the plurality of point-to-point LSPs into a point-to-multipoint LSP.
Claim 8
Independent Claim
103 words
A method in a network device comprising: identifying a plurality of receivers requesting to receive data from a source in a session; determining that the plurality of receivers do not belong to any existing point-to-multipoint label switch path (LSP); computing a plurality of point-to-point LSPs for the plurality of receivers; sending a plurality of PATH messages, each of the plurality of PATH messages pertaining to a corresponding one of the plurality of point-to-point LSPs, wherein each of the PATH messages does not include a representation of the topology of a point-to-multipoint LSP; and merging the plurality of point-to-point LSPs into a point-to-multipoint LSP.
Claim 9
Dependent Claim
20 words
The method of claim 6 wherein point-to-point LSPs computed for the plurality of receivers are to share links where possible.
Claim 10
Dependent Claim
22 words
The method of claim 6 further comprising: including an identifier of the point-to-multipoint LSP in each of the plurality of PATH messages.
Claim 11
Dependent Claim
47 words
The method of claim 8 further comprising: receiving one or more RESV messages including the identifier of the point-to-multipoint LSP from one or more downstream nodes; and creating a multicast label mapping for the point-to-multipoint LSP based on labels specified in the one or more RESV messages.
Claim 12
Dependent Claim
32 words
The method of claim 6 further comprising: maintaining a path counter associated with the point-to-multipoint LSP, the path counter specifying a number of the plurality of point-to-point LSPs in the point-to-multipoint LSP.
Claim 13
Dependent Claim
20 words
The method of claim 6 further comprising: storing the point-to-multipoint LSP in the network device as a tree data structure.
Claim 14
Dependent Claim
54 words
The method of claim 6 further comprising: identifying a new receiver joining the session; determining that the new receiver belongs to the point-to-multipoint LSP; computing a point-to-point LSP for the new receiver; sending a PATH message for the computed point-to-point LSP; and adding the point-to-point LSP for the new receiver to the point-to-multipoint LSP.
Claim 15
Dependent Claim
51 words
The method of claim 6 further comprising: determining that one of the plurality of receivers is to be removed from the session; sending a PATH TEAR message to a corresponding downstream node; and removing the plurality of point-to-point LSPs to the one of the plurality of receivers from the point-to-multipoint LSP.
Claim 16
Dependent Claim
57 words
The method of claim 13 further comprising: determining that the point-to-multipoint LSP indicates that the corresponding downstream node is involved only in a route to the one of the plurality of receivers that is to be removed; and updating a multicast label mapping for the point-to-multipoint LSP to remove a label associated with the corresponding downstream node.
Claim 17
Independent Claim
89 words
A method in a network device comprising: receiving a PATH message identifying a route from the network device to a receiver, wherein the PATH message does not include a representation of the topology of a point-to-multipoint label switched path (LSP); determining that the received PATH message is associated with an existing partial point-to-multipoint label switch path (LSP); receiving a RESV message matching the received PATH message, the received RESV message including a label; and adding the label to a multicast label mapping associated with the existing partial point-to-multipoint LSP.
Claim 18
Independent Claim
89 words
A method in a network device comprising: receiving a PATH message identifying a route from the network device to a receiver, wherein the PATH message does not include a representation of the topology of a point-to-multipoint label switched path (LSP); determining that the received PATH message is associated with an existing partial point-to-multipoint label switch path (LSP); receiving a RESV message matching the received PATH message, the received RESV message including a label; and adding the label to a multicast label mapping associated with the existing partial point-to-multipoint LSP.
Claim 19
Dependent Claim
30 words
The method of claim 15 wherein each of the received PATH message and RESV message includes an identifier of a point-to-multipoint LSP to which the existing partial point-to-multipoint LSP belongs.
Claim 20
Dependent Claim
32 words
The method of claim 15 further comprising: merging the route from the received PATH message with the existing partial point-to-multipoint LSP, the existing partial point-to-multipoint LSP being maintained by the network device.
Claim 21
Dependent Claim
16 words
The method of claim 15 wherein the existing partial point-to-multipoint LSP is represented as a tree.
Claim 22
Dependent Claim
58 words
The method of claim 16 further comprising: sending a next PATH message to a downstream node, the next PATH message including the identifier of the point-to-multipoint LSP; and incrementing a path counter maintained by the network device for the existing partial point-to-multipoint LSP, the path counter specifying a number of unicast paths in the existing partial point-to-multipoint LSP.
Claim 23
Dependent Claim
33 words
The method of claim 16 further comprising: sending a next RESV message to an upstream node upon processing the received RESV message, the next RESV message including the identifier of the point-to-multipoint LSP.
Claim 24
Dependent Claim
110 words
The method of claim 15 further comprising: determining that the received PATH message is not associated with any existing partial point-to-multipoint LSP; creating a new partial point-to-multipoint LSP; creating a path counter for the new partial point-to-multipoint LSP; sending a next PATH message to a downstream node, the next PATH message including an identifier of a point-to-multipoint LSP to which the new partial point-to-multipoint LSP belongs; receiving a RESV message matching the PATH message from the downstream node; creating a multicast label mapping for the new partial point-to-multipoint LSP; and sending a next RESV message to an upstream node, the next RESV message including the identifier of the point-to-multipoint LSP.
Claim 25
Dependent Claim
77 words
The method of claim 15 further comprising: receiving, from an upstream node, a PATH TEAR message identifying a path to be removed, the PATH TEAR message including an identifier of a point-to-multipoint LSP to which the existing partial point-to-multipoint LSP belongs; determining whether the new partial point-to-multipoint LSP indicates that the network device is involved only in a route to the receiver to be removed; and sending a next PATH TEAR message to a corresponding downstream node.
Claim 26
Dependent Claim
41 words
The method of claim 22 wherein the determining whether the existing partial point-to-multipoint LSP indicates that the network device is involved only in a route to the receiver to be removed comprises: determining whether the path counter is equal to one.
Claim 27
Dependent Claim
38 words
The method of claim 23 further comprising: determining that the path counter is equal to one; and deleting the existing partial point-to-multipoint LSP and the path counter and multicast label mapping associated with the existing partial point-to-multipoint LSP.
Claim 28
Dependent Claim
32 words
The method of claim 23 further comprising: determining that the path counter is greater than one; and removing the path identified in the PATH TEAR message from the existing partial point-to-multipoint LSP.
Claim 29
Dependent Claim
47 words
The method of claim 25 further comprising: determining that the existing partial point-to-multipoint LSP indicates that the corresponding downstream node is involved only in a route to the receiver to be removed; and removing a label associated with the corresponding downstream node from the multicast label mapping.
Claim 30
Independent Claim
121 words
A system comprising: an edge router to compute a plurality of point-to-point label switch paths (LSPs) for a plurality of receivers associated with a session, to send a plurality of PATH messages for the plurality of point-to-point LSPs, wherein each of the PATH messages does not include a representation of the topology of a point-to-multipoint LSP, and to merge the plurality of point-to-point LSPs into a point-to-multipoint label switch path (LSP); and one or more core routers, coupled to the edge router, to receive the plurality of PATH messages, to receive a plurality of RESV messages matching corresponding PATH messages, and to create a multicast label mapping for the point-to-multipoint LSP using label information contained in the plurality of RESV messages.
Claim 31
Independent Claim
121 words
A system comprising: an edge router to compute a plurality of point-to-point label switch paths (LSPs) for a plurality of receivers associated with a session, to send a plurality of PATH messages for the plurality of point-to-point LSPs, wherein each of the PATH messages does not include a representation of the topology of a point-to-multipoint LSP, and to merge the plurality of point-to-point LSPs into a point-to-multipoint label switch path (LSP); and one or more core routers, coupled to the edge router, to receive the plurality of PATH messages, to receive a plurality of RESV messages matching corresponding PATH messages, and to create a multicast label mapping for the point-to-multipoint LSP using label information contained in the plurality of RESV messages.
Claim 32
Dependent Claim
22 words
The system of claim 27 wherein each of the plurality of point-to-point LSPs is associated with an identifier of the point-to-multipoint LSP.
Claim 33
Dependent Claim
34 words
The system of claim 28 wherein the identifier of the point-to-multipoint LSP is provided by a session object included in each message exchanged between the edge router and the one or more core routers.
Claim 34
Dependent Claim
14 words
The system of claim 29 wherein the plurality of point-to-point LSPs share network resources.
Claim 35
Dependent Claim
116 words
A network element comprising: a control card to host a Resource Reservation Protocol (RSVP) module, the RSVP module to maintain one or more partial point-to-multipoint label switch paths (LSPs) established by merging unicast paths specified in a plurality of PATH messages received by the network element and to receive a plurality of RESV messages matching corresponding PATH messages, wherein each of the received PATH messages does not include a representation of the topology of a point-to-multipoint LSP; and a plurality of line cards, coupled to the control card, to contain a plurality of forwarding information bases (FIBs), wherein the plurality of FIBs is to store multicast mappings of labels specified in the plurality of RESV messages.
Claim 36
Dependent Claim
116 words
A network element comprising: a control card to host a Resource Reservation Protocol (RSVP) module, the RSVP module to maintain one or more partial point-to-multipoint label switch paths (LSPs) established by merging unicast paths specified in a plurality of PATH messages received by the network element and to receive a plurality of RESV messages matching corresponding PATH messages, wherein each of the received PATH messages does not include a representation of the topology of a point-to-multipoint LSP; and a plurality of line cards, coupled to the control card, to contain a plurality of forwarding information bases (FIBs), wherein the plurality of FIBs is to store multicast mappings of labels specified in the plurality of RESV messages.
Claim 37
Dependent Claim
44 words
The network element of claim 31 wherein the RSVP module is to add a label to one of the multicast label mappings if an RESV message containing the label pertains to a partial point-to-multipoint LSP associated with said one of the multicast label mappings.
Claim 38
Dependent Claim
31 words
The network element of claim 31 wherein each of the received PATH messages and RESV messages includes an identifier of a point-to-multipoint LSP to which a corresponding partial point-to-multipoint LSP belongs.
Claim 39
Dependent Claim
123 words
A network element comprising: a control card to include a Resource Reservation Protocol (RSVP) module, the RSVP module to establish a plurality of point-to-point label switch paths (LSPs) to reach a plurality of receivers participating in a session, to send a plurality of PATH messages for corresponding point-to-point LSPs, wherein each of the PATH messages does not include a representation of the topology of a point-to-multipoint LSP, and to merge the plurality of point-to-point LSPs into a point-to-multipoint LSP; and a plurality of line cards, coupled to the control card, to contain a plurality of forwarding information bases (FIBs), wherein the plurality of FIBs is to store muticast mappings of labels specified in a plurality of RESV messages received by the network element.
Claim 40
Dependent Claim
123 words
A network element comprising: a control card to include a Resource Reservation Protocol (RSVP) module, the RSVP module to establish a plurality of point-to-point label switch paths (LSPs) to reach a plurality of receivers participating in a session, to send a plurality of PATH messages for corresponding point-to-point LSPs, wherein each of the PATH messages does not include a representation of the topology of a point-to-multipoint LSP, and to merge the plurality of point-to-point LSPs into a point-to-multipoint LSP; and a plurality of line cards, coupled to the control card, to contain a plurality of forwarding information bases (FIBs), wherein the plurality of FIBs is to store muticast mappings of labels specified in a plurality of RESV messages received by the network element.
Claim 41
Dependent Claim
18 words
The network element of claim 34 wherein the plurality of point-to-point LSPs are to share links where possible.
Claim 42
Dependent Claim
27 words
The network element of claim 34 wherein the RSVP module is to include an identifier of the point-to-multipoint LSP in each of the plurality of PATH messages.
Claim 43
Dependent Claim
17 words
The network element of claim 34 further comprising a tree data structure to store the point-to-multipoint ISP.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 2012-01-13 | 2012-07-14 | 2013-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2016-01-13 | 2016-07-14 | 2017-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2020-01-13 | 2020-07-14 | 2021-01-13 | $7700.00 | Window Closed / Lapsed |