EP2329281A1 - Protection for provider backbone bridge traffic engineering - Google Patents
Protection for provider backbone bridge traffic engineeringInfo
- Publication number
- EP2329281A1 EP2329281A1 EP09813399A EP09813399A EP2329281A1 EP 2329281 A1 EP2329281 A1 EP 2329281A1 EP 09813399 A EP09813399 A EP 09813399A EP 09813399 A EP09813399 A EP 09813399A EP 2329281 A1 EP2329281 A1 EP 2329281A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- protection
- section
- path
- fault
- node
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 230000004044 response Effects 0.000 claims abstract description 12
- 238000011144 upstream manufacturing Methods 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 11
- 230000004075 alteration Effects 0.000 claims 2
- 238000001514 detection method Methods 0.000 abstract description 2
- 238000004891 communication Methods 0.000 description 8
- 201000000760 cerebral cavernous malformation Diseases 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000002889 sympathetic effect Effects 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J14/00—Optical multiplex systems
- H04J14/02—Wavelength-division multiplex systems
- H04J14/0278—WDM optical network architectures
- H04J14/0283—WDM ring architectures
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
- H04L12/46—Interconnection of networks
- H04L12/4641—Virtual LANs, VLANs, e.g. virtual private networks [VPN]
- H04L12/4675—Dynamic sharing of VLAN information amongst network nodes
- H04L12/4679—Arrangements for the registration or de-registration of VLAN attribute values, e.g. VLAN identifiers, port VLAN membership
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L41/00—Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
- H04L41/06—Management of faults, events, alarms or notifications
- H04L41/0654—Management of faults, events, alarms or notifications using network fault recovery
- H04L41/0659—Management of faults, events, alarms or notifications using network fault recovery by isolating or reconfiguring faulty entities
- H04L41/0661—Management of faults, events, alarms or notifications using network fault recovery by isolating or reconfiguring faulty entities by reconfiguring faulty entities
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L45/00—Routing or path finding of packets in data switching networks
- H04L45/02—Topology update or discovery
- H04L45/04—Interdomain routing, e.g. hierarchical routing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L45/00—Routing or path finding of packets in data switching networks
- H04L45/22—Alternate routing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
- H04L69/40—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J14/00—Optical multiplex systems
- H04J14/02—Wavelength-division multiplex systems
- H04J14/0287—Protection in WDM systems
- H04J14/0289—Optical multiplex section protection
- H04J14/0291—Shared protection at the optical multiplex section (1:1, n:m)
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L45/00—Routing or path finding of packets in data switching networks
- H04L45/28—Routing or path finding of packets in data switching networks using route fault recovery
Definitions
- This invention is generally related to network communications, and more particularly to protection for provider backbone bridge traffic engineering.
- PBB-TE Provider Backbone Bridge Traffic Engineering
- e2e protection an end-to-end 1 : 1 protection paradigm, referred to in this document as "e2e protection”.
- e2e protection This provides a robust protection mechanism which can be used across an arbitrary mesh of network connectivity.
- the underlying physical connectivity of many networks frequently uses rings of fiber, which makes protection over ring topologies an important scenario.
- matched pairs of nodes are used to interconnect communication links of logically adjacent rings.
- a primary path between endpoints traverses links between ones of the matched pairs of nodes, i.e., primary path nodes.
- a protection path traverses different links between the corresponding nodes of the matched pairs of nodes, i.e., protection path nodes.
- Each path in PBB-TE is associated with a VLAN ID (VID).
- VIP VLAN ID
- traffic is switched to the protection path by the headend endpoint changing the VID used on data frames.
- the end-to-end 1 : 1 protection paradigm works well, it has some drawbacks. For example, different rings may be associated with different geographic domains that are managed and operated by different organizations within the carrier, and each organization may wish to schedule maintenance outages without coordinating with other organizations.
- the frequency of faults on the extended e2e path can become significant enough that probability of a second fault occurring on the protection path before a first fault is repaired becomes unacceptable.
- An extended e2e protection paradigm can be used to mitigate this, but the number of required protection paths grows significantly as a function of the number of rings and extent of protection, e.g., protection from multiple faults across multiple rings. For example, four end-to-end paths are required for decoupling of a pair of rings in cascade since there are four possible paths. In the case of three rings in cascade, six paths are required for protection against two independent faults on any pair of rings, and eight paths are required for full protection against a single simultaneous fault on each ring. Maintaining a large number of paths can be problematic because forwarding state is directly related to the number of paths installed, and every path adds a Continuity Fault Management ("CFM”) session to the terminating nodes.
- CFM Continuity Fault Management
- a method for providing protection in a provider bridge backbone network comprises: in response to a fault, utilizing section protection if possible, where a section is defined between an ingress point and an egress point that do not span the entire provider bridge backbone network; and utilizing end-to-end protection if the fault cannot be overcome with section protection.
- apparatus for communicating between endpoints using a provider bridge backbone network comprises: an ingress point node and an egress point node which operate together to provide protection for a section of the network between the ingress point node and the egress point node, where the section does not span the entire provider bridge backbone network, the network operating in response to a fault to utilize the section protection if possible, and to utilize end-to-end protection between the endpoints if the fault cannot be overcome with section protection.
- Advantages associated with the invention include more efficient use of network resources and enhanced protection. Although the multiplicity of paths required for comprehensive protection each require forwarding state to be installed in nodes to dictate the path to be taken by traffic, data traffic only travels on one end-to-end path at any time according to the 1: 1 "head-end switching" model used by PBB-TE. This overcomes the inefficient use of network resources of previous 1+1 embodiments of section protection, which have also previously made uneconomic the deployment of section protection in combination with end-to-end path protection.
- Figure 1 illustrates an end-to-end 1 :1 protection paradigm.
- Figure 2 illustrates a paradigm with end-to-end protection, and section protection applied to the primary path only.
- Figure 3 illustrates section protection for both the primary and protection paths.
- Figure 4 illustrates an embodiment of the invention that will be used as a basis for describing responses to various different fault conditions shown in figures 5 through 10.
- Figure 5 illustrates an upstream failure in the primary route.
- Figure 6 illustrates a downstream failure in the primary route.
- Figure 7 illustrates how the responses shown in figures 5 and 6 potentially conflict under the requirement for a single Forwarding Database per bridge.
- Figure 8 illustrates a solution to the problem shown in figure 7 based on VID swap.
- Figures 9 and 10 illustrate a sympathetic switch solution to the problem shown in figure 7.
- Data communication networks may include various computers, servers, nodes, routers, switches, bridges, hubs, proxies, and other network devices coupled to and configured to pass data to one another. These devices will be referred to herein as "nodes.” Data is communicated through the data communication network by passing protocol data units, such as Internet Protocol packets, Ethernet Frames, data cells, sections, or other logical associations of data, between the nodes by utilizing one or more communication links between the nodes. A particular protocol data unit may be handled by multiple nodes and cross multiple communication links as it travels between its source and its destination over the network.
- protocol data units such as Internet Protocol packets, Ethernet Frames, data cells, sections, or other logical associations of data
- Figure 2 illustrates a protection paradigm with both end-to-end and section protection in the context of two endpoint nodes 200, 202 connected via three cascaded rings which are interconnected by matched pairs of nodes (204, 206), (208, 210).
- a primary path 212 associated with links 214, 216, 218 is protected on an end-to-end basis by protection path 220 associated with links 222, 224, 226.
- One or more sections of the primary path are also protected on a local basis, where a "section" is a link, ring, trunk or other portion of a network.
- link 214 may be protected by path 228 via link 222
- link 216 may be protected by path 230 via link 224
- link 218 may be protected by path 232 via link 226.
- the fault status of each of the paths through a section is independently monitored by a CFM session between the section endpoints.
- section protection is utilized to overcome the fault if possible, and otherwise end-to-end protection is utilized.
- the timeout period before a fault is indicated by end-to-end CFM sessions may be set to be longer than the corresponding section timeout period so that unnecessary end-to-end protection switches are not triggered.
- section protection mechanism described here may be employed over any topology, with the single constraint that the two paths forming the protected section must not cross between protection opening and closure.
- Protection for a given section may be closed on a single matched node, or corresponding nodes at the ingress and egress of the section.
- primary link 214 and the corresponding protection path 228 carried via link 222 are closed on node 204, which is matched with node 206. Consequently, a fault in link 214 can be overcome by utilizing link 228 for section protection without switching away from node 204, or needing active involvement by node 206 in the switchover process.
- end-to-end protection would be invoked as a consequence of failure of the primary end-to-end CFM session over path 212, and traffic would be switched to the links and nodes associated with protection path 220, including using node 206 rather than node 204. This advantageously mitigates problems associated with protection synchronization between matched nodes.
- both the primary and protection paths are provided with section protection. More particularly, in addition to the paths and links described with regard to figure 2, link 222 is protected by path 300 via link 214, link 224 is protected by path 302 via link 216, and link 226 is protected by path 304 via link 218. Protection for each section is independently opened and closed on both the primary and protection paths. CFM Connectivity Check sessions are maintained for the primary and protection paths between the endpoints 240, 242 to continuously determine the status of the two end-to-end paths.
- Two CFM sessions 306 (one clockwise, the other counter-clockwise) determine the status of the two paths between nodes 200 and 204 using the VID used by the primary e2e path, and two further CFM sessions 307 determine the status of the two paths between nodes 200 and 206 using the VID used by the protection e2e path.
- Two CFM sessions 308 determine the status of the two paths between nodes 204 and 208 using the VID used by the primary e2e path
- two further CFM sessions 309 determine the status of the two paths between nodes 206 and 210 using the VID used by the protection e2e path, .
- Individual section protection CFM sessions need not be created for every end-to-end path.
- the two sessions 308 could be used for all routes entering and leaving the middle ring via nodes 204 and 208.
- section protection for the primary and protection paths it is possible to tolerate one failure per ring, including the case of failure of one matched node (which faults two rings), while only doubling of the amount of state information stored at matched nodes.
- FIG. 4 illustrates an embodiment of the invention that will be used as a basis for describing responses to various different fault conditions shown in figures 5 through 10. With no loss of generality, the effect is illustrated in all cases for traffic flowing from left to right only, and "upstream” and “downstream” are used with respect to that direction of flow.
- backbone edge bridges (BEBs) 400, 402 are in communication via rings. The rings interface at matched pairs of backbone core bridges (BCBs) 404a, 404b, 406a, 406b.
- BCB includes four provider network ports (PNPs), for example 408a, 408b, 408c, 408d.
- PNPs provider network ports
- Each BEB includes a customer backbone port (CBP) 410 and two PNPs 412a, 412b.
- a primary path 420 between the BEBs is protected by an e2e protection path 424 and a section protection path 422 between BCBs 404a and 406b. Section protection for the e2e protection path is not shown in order to provide a clearer figure.
- CFM sessions are maintained between the following pairs: (BEB 400, BCB 404b); (BEB 400, BCB 404a); (BCB 404b, BCB 406b); (BCB 404a, BCB 406a); (BCB 406b, BEB 402); and (BCB 406a, BEB 402).
- FIG. 5 illustrates a fault 500 in the primary path 420 which is upstream of BCB 404a.
- traffic is rerouted by BEB 400 through PNP 412a to BCB 404b and then to BCB 404a, along the section protection path for 420 along the first section.
- BCB 404a returns the rerouted traffic to the primary path 420 at PNP 408d.
- FIG. 6 illustrates a failure in the primary route downstream of BCB 404a.
- traffic is rerouted via the section protection for the second section. More particularly, BCB 404a reroutes traffic received at its PNP 408c via which the traffic proceeds to BCB 404b and BCB 406b.
- BCB 406b forwards the traffic to BCB 406a, which returns the rerouted traffic to the primary path at its PNP 408d.
- the rerouted frames are not altered in any way at the protection opening point BCB 404a; they can and do use the same VID value (that associated with the primary e2e path).
- FIG. 7 illustrates how the responses shown in figures 5 and 6 require that the BCB matched node 404b has two forwarding paths for section protection of the primary e2e path which are used under different circumstances. Although the two paths cannot be active simultaneously, BCB 404b has no direct means of determining which path will be used and when, and it is advantageous in terms of state and complexity to maintain this lack of active involvement. Simultaneous installation of both of these forwarding paths potentially represents a conflict. In particular, different routes are associated with the same address (that of endpoint BEB 402) at BCB 404b. This is a problem because the BCB typically has only one forwarding database (FDB). One straightforward solution to this problem is to have a different forwarding database at each PNP. However, that is contrary to the Ethernet bridging standards IEEE 802. IQ and IEEE 802. lah, in which the FDB is applicable to all bridge ports, which is problematic if it is desired to comply with those standards.
- FDB forwarding database
- FIG 8 illustrates another solution to the problem illustrated in figure 7.
- the illustrated solution is based on a VID swap operation.
- a VID swap is performed across the BCB switch on the section protection path, either from upstream node to buddy node, or from buddy node to downstream node.
- the VID swap is performed at PNP 408a of BCB 404b, and again at PNP 408d, such that traffic exiting PNP 408d has the same VID as traffic entering PNP 408a, but there is no address conflict within BCB 404b because the paths are associated with different VIDs. Consequently, a single FDB per VLAN can be maintained in compliance with the Ethernet standard.
- FIGS 9 and 10 illustrate a further protection switching solution for downstream and upstream faults, respectively, in which extra state, in the form of CFM sessions, is installed on matched nodes, but there is still no explicit synchronization required between pairs of matched nodes such as 404a and 404b.
- additional pairs of CCM sessions (clockwise and counter-clockwise) are maintained between the matched node opening the section protection on the primary e2e path and that closing the protection on the protection e2e path.
- These "diagonal" sessions between matched nodes allow the upstream matched node on a section protection path to determine directly whether the downstream part of the section protection path, to the section protection closure point, is operational.
- a diagonal CCM session 900 is maintained between BCB 406a and BCB 404b.
- the diagonal sessions allow the network to determine directly whether BCB 404b can reach the section closure point at PNP 408d of BCB 406a. If a fault 902 occurs in the primary path, BCB 404b forwards traffic clockwise around the protection path to BCB 406a, because the buddy matched node 404a has also detected the fault directly from failure of its primary CCM session with BCB 406a, and switched traffic onto the section protection path.
- An upstream fault 1000 will not be detected by CCM session 900 so traffic is forwarded by default (i.e., when CFM session 900 is running correctly) by BCB 404b as if primary path on the upstream ring is faulted, i.e., fault 1000 is assumed. Note that the behaviour of BCB 404b does not matter in the case of a fault 1001 on the link between the matched nodes, which breaks both paths, because both rings are now faulted, and a subsequent fault on the primary e2e path through both sections can only be recovered by an e2e protection switch..
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US9601108P | 2008-09-11 | 2008-09-11 | |
PCT/US2009/048143 WO2010030428A1 (en) | 2008-09-11 | 2009-06-22 | Protection for provider backbone bridge traffic engineering |
Publications (2)
Publication Number | Publication Date |
---|---|
EP2329281A1 true EP2329281A1 (en) | 2011-06-08 |
EP2329281A4 EP2329281A4 (en) | 2011-12-07 |
Family
ID=42005414
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP09813399A Withdrawn EP2329281A4 (en) | 2008-09-11 | 2009-06-22 | Protection for provider backbone bridge traffic engineering |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP2329281A4 (en) |
JP (1) | JP5485998B2 (en) |
KR (1) | KR20110073445A (en) |
CN (1) | CN102150053A (en) |
CA (1) | CA2735000A1 (en) |
WO (1) | WO2010030428A1 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102496910B (en) * | 2011-12-02 | 2014-04-23 | 广州捷能电力科技有限公司 | Fault analyzing method of multi-device internet |
KR20140011530A (en) | 2012-06-29 | 2014-01-29 | 한국전자통신연구원 | Method and apparatus for managing connection path failure between data centers for cloud computing |
JP5841905B2 (en) * | 2012-07-03 | 2016-01-13 | 株式会社日立製作所 | COMMUNICATION SYSTEM, COMMUNICATION NETWORK MANAGEMENT DEVICE, AND COMMUNICATION NETWORK MANAGEMENT METHOD |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002069104A2 (en) * | 2001-02-28 | 2002-09-06 | Firstwave Intelligent Optical Networks, Inc. | Node architecture and management system for optical networks |
US20020167898A1 (en) * | 2001-02-13 | 2002-11-14 | Thang Phi Cam | Restoration of IP networks using precalculated restoration routing tables |
US20070076719A1 (en) * | 2005-10-05 | 2007-04-05 | Nortel Networks Limited | Provider backbone bridging - provider backbone transport internetworking |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001223727A (en) * | 2000-02-10 | 2001-08-17 | Nippon Telegr & Teleph Corp <Ntt> | Multi-ring path switching system |
JP2005513916A (en) * | 2001-12-21 | 2005-05-12 | ミュアヘッド、チャールズ・エス | Virtual dedicated network service supply chain management system |
US6917759B2 (en) * | 2002-01-31 | 2005-07-12 | Nortel Networks Limited | Shared mesh signaling algorithm and apparatus |
PL2204949T3 (en) * | 2005-11-11 | 2018-01-31 | Accenture Global Services Ltd | End-to-end test and diagnostic manager as well as corresponding system and method |
US8085676B2 (en) * | 2006-06-29 | 2011-12-27 | Nortel Networks Limited | Method and system for looping back traffic in QIQ ethernet rings and 1:1 protected PBT trunks |
US7768928B2 (en) * | 2006-07-11 | 2010-08-03 | Corrigent Systems Ltd. | Connectivity fault management (CFM) in networks with link aggregation group connections |
-
2009
- 2009-06-22 CA CA2735000A patent/CA2735000A1/en not_active Abandoned
- 2009-06-22 KR KR1020117005821A patent/KR20110073445A/en not_active Application Discontinuation
- 2009-06-22 WO PCT/US2009/048143 patent/WO2010030428A1/en active Application Filing
- 2009-06-22 JP JP2011526880A patent/JP5485998B2/en not_active Expired - Fee Related
- 2009-06-22 EP EP09813399A patent/EP2329281A4/en not_active Withdrawn
- 2009-06-22 CN CN2009801356260A patent/CN102150053A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020167898A1 (en) * | 2001-02-13 | 2002-11-14 | Thang Phi Cam | Restoration of IP networks using precalculated restoration routing tables |
WO2002069104A2 (en) * | 2001-02-28 | 2002-09-06 | Firstwave Intelligent Optical Networks, Inc. | Node architecture and management system for optical networks |
US20070076719A1 (en) * | 2005-10-05 | 2007-04-05 | Nortel Networks Limited | Provider backbone bridging - provider backbone transport internetworking |
Non-Patent Citations (1)
Title |
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See also references of WO2010030428A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO2010030428A1 (en) | 2010-03-18 |
CA2735000A1 (en) | 2010-03-18 |
JP5485998B2 (en) | 2014-05-07 |
CN102150053A (en) | 2011-08-10 |
EP2329281A4 (en) | 2011-12-07 |
JP2012502583A (en) | 2012-01-26 |
KR20110073445A (en) | 2011-06-29 |
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