CN102420702A

CN102420702A - IP/MPLS over WDM network protection and recovery method and system thereof

Info

Publication number: CN102420702A
Application number: CN2011103865071A
Authority: CN
Inventors: 王云; 张优训; 李伟强
Original assignee: Guangdong Planning and Designing Institute of Telecommunications Co Ltd
Current assignee: Guangdong Planning and Designing Institute of Telecommunications Co Ltd
Priority date: 2011-11-28
Filing date: 2011-11-28
Publication date: 2012-04-18
Anticipated expiration: 2031-11-28
Also published as: CN102420702B

Abstract

The invention provides an IP (Internet protocol)/MPLS (multi-protocol label switching) over WDM (wavelength division multiplex) network protection and recovery method and a system thereof. The method comprises the following steps: detecting an attribute of a failed optical path in a failed link; if the failed optical path is a working optical path, further detecting whether the working optical path has a corresponding protection optical path or not; if the work optical path has a corresponding protection optical path, transferring LSPs (label switched path) services of the working optical path to the corresponding protection optical path, and releasing resource of the working optical path, otherwise, carrying out rerouting on all LSPs services of the working optical path on an IP/MPLS layer; if the failed optical path is the protection optical path, releasing resource of the protection optical path. According to the IP/MPLS over WDM network protection and recovery method, a data network and an optical network in an IP/MPLS over WDM network can be coordinated, and network survivability is raised.

Description

IP/MPLS over WDM network protection restoration methods and system thereof

Technical field

The present invention relates to the technical field of IP/MPLS over WDM dynamic optical network, relate in particular to a kind of IP/MPLS over WDM network protection restoration methods, and a kind of IP/MPLS over WDM network protection recovery system.

Background technology

Along with popularizing of IP operation; The fast development of high speed router technology; And wavelength division multiplexing (WDM; Wavelength Division Multiplex) a large amount of employings of technology, at present in key communication carrier online (comprising public backbones, provincial main line and metropolitan area main line), the two-tier system that the IP/MPLS router directly is carried on the WDM optical-fiber network is very ripe and universal.

As shown in Figure 1; IP (Internet Protocol)/MPLS (Multi-Protocol Label Switching) network is responsible for to terminal use (end user) (the Quality of Service that has QoS being provided; Service quality) Network; The rich data business and the multimedia application that guarantee; Support traffic engineering TE (TEtraffic engineering), SLA (Service-Level Agreement), VPN (Virtual Private Network), AAA (Authorization, Authentication, function such as Accounting); The ASON of bottom then is responsible for the client on it, and promptly the IP/MPLS network provides stable, extendible, and powerful transmission network function, and we are referred to as IP/MPLS/WDM network or IP/MPLS over WDM network such bearer network.

As far as communication network, professional survivability (Survivability, promptly when network failure for the rapid protection and the recovery of service channel) is a vital problem.In the WDM optical-fiber network, (for example fiber break Fiber-Cut) can cause all to break down through the business on the optical channel of this faulty link to the fault of networking component.Because present single fiber can have been supported the high service rate of Tb/s, so the fault of optical channel can cause serious a large number of services to interrupt.Therefore for those operator and telecommunications manufacturers that hopes to lay big capacity optical transfer network, the existence performance of network is the importance that they pay close attention to.

The surviving policy of communication network can be divided into protection strategy (protection), or recovery (restoration); Can be based on (path-based) of passage, also can be based on (link-based) of link; Can be based on (ring-based) of annular, also can be based on (mesh-based) of mesh shape; For resource conservation, can be privacy protection (dedicated protection), also can be share protect (shared protection).

At present, in IP/MPLS over WDM network, the surviving policy of network is separated basically and is carried out; Promptly in the data network that the IP/MPLS router constitutes; Can use the surviving policy of IP/MPLS network, for example: quick heavy-route (FRR), 1+1LSPs protection; 1: 1LSPs protection etc., deal with traffic failure; And in the WDM optical-fiber network, then can adopt some surviving policy of optical transfer network, for example: 1+1 Optical Channel Protection (Lightpath), 1: 1 Optical Channel Protection, optical channel recover to accomplish the protection to business.

But; At present in the existence scheme of IP/MPLS over WDM network; The surviving policy of data network is separated with the surviving policy of optical-fiber network, does not take into account the advantage of the surviving policy of each layer, and the surviving policy between the multilayer is less than coordinating; Do the waste that not only can cause resource like this, but also can cause alarm windstorm and cause confusion.

Summary of the invention

The technical problem that the present invention will solve is to provide a kind of data network and the optical-fiber network that can coordinate in the IP/MPLS over WDM network, improves the IP/MPLS over WDM network protection restoration methods of network survivability.

A kind of IP/MPLS over WDM network protection restoration methods comprises: the attribute of the fault optical channel in the detection failure link; Whether if said fault optical channel is the work optical channel, then further detecting said work optical channel has corresponding protection optical channel; If said work optical channel has corresponding protection optical channel, then the LSPs business on the said work optical channel is transferred on the corresponding protection optical channel, and discharged the resource of said work optical channel; If said work optical channel does not have corresponding protection optical channel, then all the LSPs business on the said work optical channel are carried out heavy-route at the IP/MPLS layer; If said fault optical channel is the protection optical channel, then discharge the resource of said protection optical channel.

The technical problem that the present invention will solve also is to provide a kind of data network and the optical-fiber network that can coordinate in the IP/MPLS over WDM network, improves the IP/MPLS over WDM network protection recovery system of network survivability.

A kind of IP/MPLS over WDM network protection recovery system comprises: channel detecting module, protection attribute detection module, professional shift module, heavy-route module and resource release module.Said channel detecting module is used for the attribute of the fault optical channel of detection failure link; Said protection attribute detection module is used for when said fault optical channel is the work optical channel, and whether detect said work optical channel has corresponding protection optical channel; Said professional shift module is used for when said protection attribute detection module detects said work optical channel corresponding protection optical channel is arranged, the business of the LSPs on the said work optical channel being transferred on the corresponding protection optical channel; Said heavy-route module is used for when said protection attribute detection module detects said work optical channel and do not have corresponding protection optical channel, at the IP/MPLS layer business of all LSPs on the said work optical channel being carried out heavy-route; Said resource release module is used to discharge the resource of said fault optical channel.

Compared with prior art; In IP/MPLS over WDM network protection restoration methods of the present invention and the system thereof, at first discerning the fault optical channel is work optical channel or protection optical channel, if the work optical channel; Judge then whether it has corresponding protection optical channel; If have, then the LSPs business on the said work optical channel is transferred on the corresponding protection optical channel and moved, the LSPs business of fault optical channel can not interrupted; If do not have the protection optical channel; Then all the LSPs business on the said work optical channel are carried out heavy-route at the IP/MPLS layer; Through heavy-route all the LSPs business on the said work optical channel are reassigned new optical channel, business can be moved through continuation at new light.If said fault optical channel is the protection optical channel, then discharge the resource of said protection optical channel, fault can be recovered as early as possible.

In the such multitiered network of IP/MPLS over WDM; Each layer all has its advantage and deficiency on survivability; Like the coarsegrain of WDM photosphere, fast, and to the general business recovery characteristic in upper strata, but can't protect and recover according to the characteristic of high-level business; Protection/the recovery of IP/MPLS router layer has the flexibility of bandwidth availability and protection, but has slow-footed drawback, and the fault that can't find out physical layer.

Through IP/MPLS over WDM network protection restoration methods of the present invention and system thereof; Can the binding data network layer and the survivability characteristics of optical-fiber network layer; Take all factors into consideration on the basis of topological sum utilization of resources information of IP/MPLS layer and WDM photosphere; The survivability of associating multilayer can improve the dynamic survivability of associating of IP/MPLS overWDM network.Proved that through simulation result method and system of the present invention have more excellent resource utilization and existence efficient, comprise protection efficient and recover efficient.

Description of drawings

Fig. 1 is the IP/MPLS over WDM schematic network structure of prior art;

Fig. 2 is the schematic flow sheet of IP/MPLS over WDM network protection restoration methods of the present invention;

Fig. 3 is the structural representation of IP/MPLS over WDM network protection recovery system of the present invention.

Fig. 4 is the structural representation of a kind of preferred implementation of IP/MPLS over WDM network protection recovery system of the present invention;

Fig. 5 is sketch map fault time of IP/MPLS over WDM network;

Fig. 6 is the sketch map of the physical topology model among the embodiment;

Fig. 7 is under Mesh-Torus and NSFNet topology, the contrast sketch map of the dynamic blocking performance that changes with offered load of the present invention and other network survivability strategy;

Fig. 8 is under Mesh-Torus and NSFNet topology, the contrast sketch map of the present invention and other network survivability strategy dynamic blocking performance under heterogeneous networks link failure frequency;

Fig. 9 is under Mesh-Torus and NSFNet topology, the contrast sketch map of the present invention and the existence efficient of other network survivability strategy under the heterogeneous networks load;

Figure 10 is under Mesh-Torus and NSFNet topology, the contrast sketch map of the present invention and the existence efficient of other network survivability strategy under different single link failure frequencies.

Embodiment

See also Fig. 2, Fig. 2 is the schematic flow sheet of IP/MPLS over WDM network protection restoration methods of the present invention.

Said IP/MPLS over WDM network protection restoration methods may further comprise the steps:

S101, the attribute of the fault optical channel in the detection failure link; If said fault optical channel is the work optical channel, then execution in step S102; If said fault optical channel is protection optical channel, then execution in step S105.

When the optical-fiber network layer breaks down; At first utilize the protection optical channel of photosphere to implement business recovery, so, in this step; Judge that at first the optical channel attribute that breaks down is work optical channel or protection optical channel; If the work optical channel, can judge whether it has corresponding protection optical channel, if having then can utilize corresponding protection optical channel to implement business recovery.

S102, whether detect said work optical channel has corresponding protection optical channel; If said work optical channel has corresponding protection optical channel, then execution in step S103; Otherwise execution in step S104.

S103 transfers to the LSPs business on the said work optical channel on the corresponding protection optical channel, and discharges the resource of said work optical channel;

S104 carries out heavy-route at the IP/MPLS layer to all the LSPs business on the said work optical channel;

S105 discharges the resource of said protection optical channel.

Through IP/MPLS over WDM network protection restoration methods of the present invention and system thereof; The survivability characteristics that can combine IP/MPLS data network layer and WDM optical-fiber network layer; Take all factors into consideration on the basis of topological sum utilization of resources information of IP/MPLS layer and WDM photosphere; The survivability of associating multilayer can improve the dynamic survivability of associating of IP/MPLS over WDM network.Specifically, can improve the level of resources utilization and existence efficient of IP/MPLS over WDM network.

In this execution mode, before the execution in step S101, the LSPs request for arriving utilizes corresponding dynamic joint route algorithm, sets up optical channel at photosphere.And, utilize RWA (Routingand Wavelength Assignment, route in the WDM network and Wavelength assignment algorithm) simultaneously, set up the protection optical channel for each new optical channel of successfully setting up at photosphere; If said passage is set up module and is set up the success of protection optical channel; Then said protection attribute is provided with module and the safe condition of said work optical channel is labeled as protects (" Protected "), shows that all the LSPs business in this work optical channel all are protected; If said passage is set up module and set up the failure of protection optical channel, then said protection attribute is provided with module the safe condition of said work optical channel is labeled as not protection (" Unprotected ").This is the WDM photosphere sharing channel protection strategy under the IP/MPLSover WDM network.

Then in step S102, can judge whether it has corresponding protection passage through the safe condition that detects said work optical channel:

If the safe condition of said work optical channel, is then judged said work optical channel for protecting corresponding protection optical channel is arranged;

If the safe condition of said work optical channel is not protection, judge that then said work optical channel does not have corresponding protection optical channel.

Can obtain the corresponding protection optical channel that whether has of said work optical channel apace through said safe condition mark; Thereby can utilize said protection optical channel to carry the business of moving on the said work optical channel very first time, lower the influence of fault service operation.

Further, when in step S101, detecting said fault optical channel for the protection optical channel, can further carry out following steps: the safe condition of the work optical channel that said protection optical channel is corresponding is labeled as not protection.

If the optical channel of fault is the protection optical channel; Then said protection optical channel no longer plays the effect of protection to the corresponding work optical channel; Therefore; The safe condition of corresponding work optical channel is labeled as not protection, so that when said service aisle breaks down, can judge according to said safe condition mark.

As a kind of preferred implementation,, at the IP/MPLS layer all the LSPs business on the said work optical channel are carried out heavy-route and specifically can realize through following steps at step S104:

The failure message of LSPs on the said work optical channel is sent to the start node of each said LSPs with signaling method, promptly utilizes signaling mechanism the failure message of fault LSPs to be notified the start node of fault LSP;

At the IP/MPLS layer the said LSPs that receives failure message is carried out heavy-route.

Through signaling mechanism, with the failure message of optical-fiber network layer, be sent to the data network layer, and at the IP/MPLS layer LSPs that breaks down carried out heavy-route and handle.Realize message communication and coordination between optical-fiber network layer and the data network layer, the processing through the data network layer makes the fault of optical-fiber network layer obtain handling and recovering to the influence of business, has strengthened the survivability of IP/MPLS over WDM network.

As a kind of preferred implementation, after the IP/MPLS layer carries out heavy-route to all the LSPs business on the said fail operation optical channel, further carry out following steps:

If said LSPs is carried out the heavy-route success, then set up and recover LSPs, the business of the LSPs on the said fail operation optical channel is transferred on the said recovery LSPs;

If said LSPs is carried out the heavy-route failure, then interrupt the business of said LSPs, after the business recovery of wait IP/MPLS layer is accomplished, discharge the resource of said fail operation optical channel.

Through setting up new recovery LSPs; Can effectively carry the business datum of the LSPs of fault optical channel; The business datum of the LSPs of outage optical channel under the situation of heavy-route failure; And after the business recovery of IP/MPLS layer was accomplished, the resource that discharges said fail operation optical channel was given physical topology, makes resource to be utilized effectively.

For above-mentioned steps S105, before the resource that discharges said protection optical channel, also comprise step:

Judge whether said protection optical channel has the business of LSPs to move;

If there is the business of LSPs to move, then interrupt the business of the LSPs on said error protection optical channel, the resource that discharges said protection optical channel is again given physical topology, makes the business of the LSPs on the fault optical channel can not continue misinformation.And then get back to the protection of photosphere.

Compared with prior art; IP/MPLS over WDM network protection restoration methods of the present invention, at first discerning the fault optical channel is work optical channel or protection optical channel, if the work optical channel; Judge then whether it has corresponding protection optical channel; If have, then the LSPs business on the said work optical channel is transferred on the corresponding protection optical channel and moved, the LSPs business of fault optical channel can not interrupted; If do not have the protection optical channel; Then all the LSPs business on the said work optical channel are carried out heavy-route at the IP/MPLS layer; Through heavy-route all the LSPs business on the said work optical channel are reassigned new optical channel, business can be moved through continuation at new light.If said fault optical channel is the protection optical channel, discharge the resource of said protection optical channel, fault can be recovered as early as possible.

Because the protection of photosphere has fast, bandwidth efficient, coarsegrain, simple operation and other advantages; And the recovery of IP/MPLS layer has simultaneously advantages such as the flexibility of business recovery, high recovery validity, small grain size; So IP/MPLS over WDM network protection restoration methods of the present invention combines the protection of photosphere and the recovery of IP/MPLS layer, used the IPRA (Integrated Protection Restoration Algorithm) of the recovery of a kind of protection of uniting photosphere and IP/MPLS layer.This method has combined the high resource utilization of photosphere sharing channel protection OSPP (Optical Shared Path Protection); The LSPs of the layer of business recovery time, and IP/MPLS fast dynamically recovers the flexibility of IBUR (Integrated Bottom UpRestoration) and ITDR (Integrated Top Down Restoration).Have preferably resource availability and existence performance, this be since its combine the protection of photosphere sharing channel fast, coarsegrain and resource availability, and flexibility that dynamically recovers in IP/MPLS layer small grain size and higher recovery efficient.

See also Fig. 3, Fig. 3 is the structural representation of IP/MPLS over WDM network protection recovery system of the present invention.

IP/MPLS over WDM network protection recovery system comprises:

Channel detecting module 11 is used for the attribute of the fault optical channel of detection failure link;

Protection attribute detection module 12 is used for when said fault optical channel is the work optical channel, and whether detect said work optical channel has corresponding protection optical channel;

Professional shift module 13 is used for when said protection attribute detection module detects said work optical channel corresponding protection optical channel is arranged, the business of the LSPs on the said work optical channel being transferred on the corresponding protection optical channel;

Heavy-route module 14 is used for when said protection attribute detection module detects said work optical channel and do not have corresponding protection optical channel, at the IP/MPLS layer business of all LSPs on the said work optical channel being carried out heavy-route;

Resource release module 15 is used to discharge the resource of said fault optical channel.

Compared with prior art; IP/MPLS over WDM network protection recovery system of the present invention; It is work optical channel or protection optical channel that said channel detecting module 11 is at first discerned the fault optical channel; If the work optical channel, then said protection attribute detection module 12 judges whether it has corresponding protection optical channel, if having; Then the LSPs business on the said work optical channel is transferred on the corresponding protection optical channel and moved, the LSPs business of fault optical channel can not interrupted by said professional shift module 13; If do not have the protection optical channel; Then at the IP/MPLS layer all the LSPs business on the said work optical channel are carried out heavy-route by said heavy-route module 14; Through heavy-route all the LSPs business on the said work optical channel are reassigned new optical channel, business can be moved through continuation at new light.When if resource release module 15 is the protection optical channel at said fault optical channel, discharge the resource of said protection optical channel; After the business of LSPs on said professional shift module will be worked optical channel is transferred on the corresponding protection optical channel, perhaps after the LSPs heavy-route on the said work optical channel, discharge the resource of said work optical channel, fault can be recovered as early as possible.

See also Fig. 4, Fig. 4 is the structural representation of a kind of preferred implementation of IP/MPLS over WDM network protection recovery system of the present invention.

In this execution mode, said IP/MPLS over WDM network protection recovery system further comprises: passage is set up module 16 and with the protection attribute module 17 is set.

Said passage is set up module 16 and is used to set up the work optical channel, and each said work optical channel is set up the protection optical channel;

Said protection attribute is provided with module 17 when said passage is set up module 16 and set up the success of protection optical channels, the safe condition of said work optical channel is labeled as protects; When said passage is set up module 16 and set up the failure of protection optical channels, the safe condition of said work optical channel is not labeled as protection.

Then, the safe condition that said protection attribute detection module 12 detects said work optical channel judges that said work optical channel has the protection optical channel of correspondence when protecting; When not protecting, judge that said work optical channel does not have corresponding protection optical channel at the safe condition of said work optical channel.

Further, said protection attribute is provided with module 17 when said channel detecting module 11 detects said fault optical channel for the protection optical channel, and the safe condition of the work optical channel that said protection optical channel is corresponding is labeled as not protection.

In this execution mode, said heavy-route module 14 comprises:

Signalling trouble module 141 is sent to the failure message of the LSPs on the said work optical channel start node of each said LSPs with signaling method;

Heavy-route Executive Module 142 carries out heavy-route at the IP/MPLS layer to the said LSPs that receives failure message.

Enter a ground, the said IP/MPLS over WDM network protection recovery system of this execution mode also comprises: LSPs sets up module 18 and service disconnection module 19;

Said LSPs sets up module 18 when 14 couples of said LSPs of said heavy-route module carry out the heavy-route success, sets up and recovers LSPs, and said professional shift module 13 is transferred to the business of the LSPs on the said work optical channel on the said recovery LSPs;

When said service disconnection module 19 is carried out the heavy-route failure at 14 couples of said LSPs of said heavy-route module, interrupt the business of said LSPs; And said resource release module 15 discharges the resource of said work optical channel after the business recovery of IP/MPLS layer is accomplished.

Through setting up new recovery LSPs; Can effectively carry the business datum of the LSPs of fault optical channel; The business datum of the LSPs of outage optical channel under the situation of heavy-route failure; And after the business recovery of IP/MPLS layer was accomplished, the resource that discharges said work optical channel was given physical topology, makes resource to be utilized effectively.

Enter a ground; The said IP/MPLS over WDM network protection recovery system of this execution mode also comprises: operation attribute detection module 20; Whether the protection optical channel that said operation attribute detection module 20 is used for failure judgement has the business of LSPs to move; When said service disconnection module 19 has the business of LSPs moving at said protection optical channel, interrupt the business of the LSPs on said protection optical channel.The resource that said resource release module 15 discharges said protection optical channel is given physical topology.

In order to further specify technological merit of the present invention; By l-G simulation test; The performance that has comprehensively compared various Combined Protection and associating recovery policy; High spot reviews dynamic blocking performance of the present invention (characterize strategy resource utilization) and dynamic existence efficient (comprising service protection/recovery efficient, the service disconnection rate), and the present invention and other various dynamic syndicated surviving policy contrasted.Particularly, resource utilization, protection/recovery efficient, service disconnection rate to the various dynamic surviving policy of WDM optical-fiber network compare under various network topology, offered load, fault occurrence frequency, fault correction time.

At first, carry out network modelling:

With G (N, L, the W) physical topology of expression IP/MPLS over WDM network, N representation node collection wherein, L represents the two-way link collection, W is the wavelength available collection on every optical fiber.Suppose that every link all is made up of a pair of one-way optical fiber link in the opposite direction, every supported wavelength collection of optical fiber all be λ 1, and λ 2 ..., λ | w|}.The light path of considering also is two-way light path.Node number, number of links and number of wavelengths are used respectively | N|, | L| with | W| representes.Here we consider the network model of equity, and each node all is to be made up of IP/MPLS router and OXC (Optical Cross-Connect, optical cross connect, the node of WDM network), and supposes that all OXC do not have wavelength conversion function.The disposal ability of supposing the IP/MPLS router in addition is unrestricted, and the number of the optical transceiver among the OXC is also unrestricted.

With Pv (N, Lv, Wv) virtual topology of expression IP/MPLS over WDM network; The dynamic network of promptly seeing that is constituted by IP/MPLS router node and the WDM layer optical channel link set up from the IP/MPLS layer; N representation node collection wherein, Lv representes the virtual link collection, Wv representes empty wavelength collection.Wherein Lv and Wv are dynamic changes, when having optical channel between any two nodes, just have virtual link between them, and the number of the empty wavelength in each virtual link is not changeless, but along with the state of network in dynamic change.

LSP (Label Switched Path, label switched path) is a connection-oriented business channel in the IP/MPLS network, and it connects the request of foundation can be expressed as (si; Di; Bi), si wherein, di ∈ N; Expression should be asked pairing source, destination node router respectively, and bi representes the bandwidth of connection request LSP.Be without loss of generality, can use the base unit of the transmission rate of single wavelength as bandwidth request.Usually, the bandwidth requirement of LSP foundation request is all less than a base unit.

Set up dynamic single link failure model based on this:

In the optical-fiber network model, suppose that all physical links all are made up of the opposite one-way optical fiber link of both direction (Unidirectional Link), and claim that such link is two-way link (BidirectionalLink).Comprise the wavelength of some in each one-way optical fiber link, and claim that such wavelength is a wavelength channel (Wavelength Channel), or abbreviate channel (Channel) as.Article one, optical channel is by a link sequences and wavelength uniquely identified wherein.Since we do not consider wavelength Conversion at each node, therefore, an optical channel is to be made up of a channel sequence with identical wavelength.

Usually, the fault in the optical-fiber network is from link failure, node failure (optical transceiver, light opens the light, preceding/rearmounted optical amplifier failures, power supply trouble etc.) and some other hardware fault, like circuit image intensifer or the like.In these faults, link failure (Link-Failure) is modal fault like Fiber-Cut, and the probability of happening of single link failure also is the fault model that the most often adopts under study for action much larger than multilink fault.At this, estimate the survivability of WDM optical-fiber network with single link failure (Single-link failure).Consider a more actual single link failure model.In this model, two independently parameters are arranged: average link time between failures (MTBF, Mean Time Between Failures) Ti and average link failure repair time (MTTR, Mean Time To Repair) Tr.Wherein the blanking time of Ti two single link failure representing to take place in succession, its size has determined the frequency that link failure takes place in the network, and the Ti single link failure frequency of the bright network of novel more is high more; Tr has then represented and has repaired single link failure used average time.In model, these two parameters are incoherent, and promptly they can independent variation.Since in the network model of setting up, all links all are two-way links, so a single link failure will cause the fault of two one way links in the opposite direction.

As shown in Figure 5, in moment ti (i=1,2,3;) single link failure has taken place randomly, this single link failure state will keep a period of time up to moment ti ' (i=1,2 then; 3 ...), then the time between ti and the ti+1 is exactly average link time between failures Ti; Time between ti and the ti ', just dash area is represented average link fault correction time Tr.In the time interval, this faulty link all is disabled for any connection request, up to moment ti ' at Tr.In order to guarantee all have only a link failure to take place at every turn, whenever supposition all has Tr＜Ti again.

Along with pushing ahead of simulation time, Ti at set intervals, a single-link is selected to produce fault randomly, and this malfunction will continue a period of time Tr up to being repaired to normal.At each moment point ti, all will be interrupted (Disrupted) through the business on the optical channel of this faulty link.

Be the advantage of explaining that IP/MPLS over WDM network protection restoration methods of the present invention has compared with prior art; To IP/MPLS over WDM multitiered network; Define following dynamic simulation performance parameter and assess this tactful network survivability performance: resource utilization, protection efficient, recovery efficient and service disconnection rate, specific as follows:

Resource utilization η u (Resource Utilization): η u is defined as the ratio of Ns and Nc, and η u=Ns/Nc is the connection call request that do not get clogged shared ratio in the all-calls connection request.The needed Internet resources of a kind of protection/recovery policy of this parametric representation.In dynamic simulation, represent the resource utilization of various strategies usually with the blocking rate that connects call request.Call blocking rate (BlockingProbability) Pb is defined as the ratio of the shared all-calls connection request of connection call request that gets clogged; Be Pb=(Nc-Ns)/Nc; Consider in the survivability strategy; Some are that the business of the LSPs that gets clogged is owing to link failure is interrupted; So we have defined an effective blocking rate (Effective Blocking Probability) Pe again, be used for representing that those get clogged and the ratio of shared all the connection request LSPs of LSPs that are interrupted Pe=(Nc-Ns+Nd)/Nc.Can find out, connect in the obstruction of calling out owing to effective blocking rate has also counted the connection of interrupting falling, so effective blocking rate is greater than the value of blocking rate.The relation of blocking rate and resource utilization is that the blocking rate of network is high more, explains that the resource utilization of network is just low more.

Protection efficiency eta p (Protection Efficiency): η p=Np/Nw, this parametric representation is when network generation single link failure, and by means of protection strategies, the business on all fail operation LSPs is by the ratio of success protection.

Recover efficiency eta r (Restoration Efficiency): η r=Nr/Nw, this parametric representation is when network generation single link failure, and by means of corresponding recovery policy, the business on all fail operation LSPs is by the ratio of success protection.

Existence efficiency eta s (Survival Efficiency): η s=(Np+Nr)/Nw; This parametric representation is when network generation single link failure; By means of corresponding protection and recovery policy, the business on all fail operation LSPs is by the ratio of successfully protecting and recovering.The existing protection that is proposed above this parameter is used for has the Combined Protection/recovery policy of recovery again.

Service disconnection rate η d (Service Disruption Ratio): η d=Nd/Ns, the meaning of this parameter does, because the single link failure of network, the ratio of the LSPs that the professional shared total success of LSPs that causes being interrupted is set up.The LSPs business of interrupting falling mainly contains two parts and constitutes: first fail operation LSPs; These fail operations LSPs does not have resource conservation to use when link failure takes place; Be that state is the fail operation LSPs that does not protect (Unprotected), or those states are protected the fail operation LSPs of the state of LSP for operation (Running) for the still corresponding shared of protecting (Protected).A part is to be made up of protection LSPs in addition, and when these error protections LSPs was in operation (Running) state, the business on it also can be interrupted.The value of this parameter is more little, explains that corresponding surviving policy is good more.

For ease of comparing, we have adopted two physical topologies: the NSFNet (Fig. 6 (b)) of the Mesh-Torus of 16-Node 32-Link (Fig. 6 (a)) and 16-Node 25-Link.Two topologys have identical node number, but have different average nodal degree.Wherein Mesh-Torus is a rule topology, and the node degree of all nodes is 4, and NSFNet then is the irregular topology of an actual operation, and the average nodal degree is 3.125.Through more different topologys, eliminate of the influence of the difference of topology itself to simulation result.In these two topologys, all physical fiber links all are two-way link (Bi-directional).And suppose that the number of wavelengths in all one way links (Uni-directional) is W=8.

In simulation model, we adopt dynamic service amount pattern.Service request be distributed in fifty-fifty all nodes between, promptly all nodes all possibly become source node and destination node to s-d.Connection request arrives network and distributes according to Poisson, and average arrival rate is λ.The passage of the optical channel of having set up keeps deferring to negative exponent and distributes, and the mean holding time of passage is 1/ μ.Then the load of network we can represent with ρ=λ/μ.Here we establish 1/ μ=1, so the size of λ has just been represented the load of network.The connection request number of times of our total optical channel is 1000000 times in addition, and promptly each data point in the simulation result all is the simulation result of 1000000 LSP connection requests.In addition; In the emulation experiment below, the dynamic RWA strategy that we adopt is K-Shortest-Link-Disjoint-Path Algorithm (the minimal path routing algorithm of K bar link disjoint) and First-Fit Algorithm (initial hit Wavelength assignment algorithm).

Below, provide to other required parameter symbols of IP/MPLS over WDM network modelling emulation:

Nc: LSP total in the single dynamic emulation experiment connects call request number, NC=1000000 here.

Ns: in whole dynamic simulation process, the LSP linking number of successfully setting up.

Nd: in whole dynamic simulation process, total service disconnection number, the number of the working LSP that promptly is interrupted.For working LSP s, when single link failure took place, if there is not available resource conservation, then the business on this working LSP will be interrupted.For protection LSPs, if they are in " Running " state, then the protection business of operation also will be interrupted above that.For recovery policy,, so also will cause professional interruption if fail to the working LSP s that interrupts falling finds available resource conservation.

Nw: in whole dynamic simulation process, the number that the working LSP s that causes owing to single link failure breaks down, promptly total fail operation LSPs number (Total Number of Failed WorkingLSPs).

Np: in whole dynamic simulation process; When single link failure takes place, successfully recover the number (Total Number of Failed Working LSPs thatare Successfully Protected) of the fail operation LSPs of business because protection is tactful.

Nr: in whole dynamic simulation process, when single link failure takes place, successfully recover the number (Total Number of Failed Working LSPs thatare Successfully Restored) of the fail operation LSPs of business owing to recovery policy.

Pr: protective rate, a parameter in the protection strategy.When setting up working LSP s, set up the ratio of successfully setting up protection LSPs for it simultaneously.

1/ μ: the average channel retention time of the LSPs that has set up, we suppose that the passage retention performance of LSPs is to obey negative exponent to distribute here.In our emulation experiment, we establish 1/ μ is fixed value, and 1/ μ=1 chronomere is not general, and our all here chronomeres of supposition are " second ", i.e. 1/ μ=1s.

λ: the average arrival rate of the connection request of LSPs in the unit interval, we suppose that the characteristic that reaches of LSPs defers to Poisson and distribute here.Usually λ/μ is used to characterize the busy extent of network, the business load of network just, since 1/ μ=1, so in our emulation, the size of λ value is just directly represented the load of network.

W: on the optical-fiber network physical topology, the number of wavelengths in the single fiber link, we suppose that the number of wavelengths in all links all equates W=8 here.

Ti: the average time interval of single link failure, i.e. MTBF.

Tr: the mean time to repair of single link failure, i.e. MTTR.

Below with prior art IP/MPLS over WDM network protection method commonly used be example, comparative illustration:

1) the protection strategy O-SPP of WDM photosphere (Optical-layerShared Path Protection) in the IP/MPLS over WDM network

Under this strategy, all be to accomplish at photosphere for the protection of Network.Under IP/MPLS overWDM network architecture, the service connection request that we considered all is the LSP at the IP/MPLS layer, these LSP all be less than or much smaller than the capacity of a wavelength channel.So when network generation single link failure, need protect operation to all LSP that carried on all wavelengths in this faulty link, only the protection recovery operation of this moment is unit with the wavelength channel.I.e. this moment, when we recover in the protection of only considering photosphere, do not consider the specific object of the business on upper strata.But we are when investigating the survivability performance of network, then must consider to fall institute's loaded service characteristic in the network.Specifically, in the parameters such as professional number that the number of considering the call connection request number of network, interrupting service, success are protected, we are to the LSP connection request of small grain size.

2) associating designated lane protection IDPP (Integrated dedicated path protection)

In this strategy, the protection LSP (ProtectionLSP) of all working LSP (Working LSP) is special-purpose.When a LSP connection request arrives, at first utilize the joint route strategy to set up a working LSP, and then utilize the joint route strategy to set up a protection LSP for it for it.When setting up working LSP and protecting LSP; We all be at first photosphere set up a source node to destination node between an optical channel; On this optical channel, set up needed LSP then again; If set up new optical channel failure at photosphere, then on the virtual topology that the IP/MPLS router constitutes, directly set up LSP.Have only when on physical topology and virtual topology, all can't set up working LSP; This LSP connection request will get clogged; And ought successfully set up working LSP, and can't set up when protecting LSP, this working LSP will be labeled " Unprotected " so.

3) associating sharing channel protection ISPP (Integrated Shared path protection)

In this strategy, can the share protect resource between the protection LSP (ProtectionLSP) of different working LSP (Working LSP).When a LSP connection request arrives, at first utilize dynamic syndicated routing policy to set up a working LSP, and then utilize the joint route strategy to set up a protection LSP for this working LSP for it.The method of setting up working LSP is with the protection of associating designated lane.

When setting up protection LSP, for shared resource to greatest extent, the enterprising walking along the street of virtual topology that we at first constitute at the IP/MPLS router by and set up protection LSP.When setting up protection LSP, our principle is that this protection LSP can not take the resource of any working LSP, but can share the resource of the protection LSP that has set up.And in the share protect resource, because the capacity of LSP is not changeless, but discrepant, so there is the adjustment problem of a protection bandwidth.This moment we must seek a maximum as the share protect bandwidth between the bandwidth of bandwidth and the protection LSP that promptly will set up of the protection LSP that will share; If adjusted share protect bandwidth has surpassed the residual capacity in the empty wavelength; Protect LSP to set up failure so, and the adjustment of cancellation protection bandwidth.After protection LSP is set up in success, check this protection LSP each jumping on virtual topology,, its state is set is " Idle " for the resource conservation of having only a protection LSP to take.

If on virtual topology, set up protection LSP failure, so we be transferred to again photosphere set up a source node to destination node between an optical channel, on this optical channel, set up needed protection LSP then again.

When on physical topology and virtual topology, all can't set up working LSP, this LSP connection request will get clogged, and ought successfully set up working LSP, and can't set up when protecting LSP, and this working LSP will be labeled " Unprotected " so.

4) associating top-down recovery policy ITDR (Integrated Top-Down Restoration)

In this strategy; After detecting the single link failure of network; At first notify the source node of all fault LSPs, trigger the dynamic recovery process of LSP then at the IP/MPLS layer, if success through signaling mechanism; Remove to set up new recovery passage through corresponding signaling mechanism, the switching services on the fault LSPs is gone to new recovery passage.If the dynamic recovery failure of the fault LSP on the IP/MPLS layer; Change photosphere again over to this moment so,, rebulid the recovery optical channel through RWA; If success; Set up new recovery optical channel, on this recovers passage, set up new LSP then, with the switching services on the fault LSP to new recovery LSP.

The ITDR strategy has absorbed the flexibility and the high efficiency of the small grain size business recovery on the IP/MPLS layer, and can on the IP/MPLS layer, implement some recovery policies based on priority and QoS, because high-rise characteristic that can identification services.This tactful shortcoming is, owing to recover at high level, inevitably can sacrifice some resources effective property, can cause required operation more in the high level recovery in addition, and required recovery time is excessive.

5) associating bottom-up recovery policy IBUR (Integrated Bottom-Up Restoration)

In this strategy; After detecting the single link failure of network; At first through signaling mechanism failure message is sent to the start node of all fault optical channels, triggers RWA then the fault optical channel is carried out heavy-route, if the route success at photosphere; Then all the LSP switching services on the fault optical channel are gone to new protection optical channel, and discharge the resource of fault optical channel.If in the heavy-route failure of photosphere to the fault optical channel; Through signaling mechanism failure message is notified the start node of fault LSP again; On the IP/MPLS layer, carry out the heavy-route of fault LSP then; If success is then set up new recovery LSP through signaling, the business of switch failure LSP extremely new protection LSP gets on.If the failure of the heavy-route of fault LSP then interrupts the business on this fault LSP.After all fault LSP are disposed, discharge the shared resource of all fault optical channels on the faulty link.

The advantage of IBUR is guaranteed the photosphere recovery high-speed, the bandwidth availability that coarsegrain recovers, and action required is less relatively, it is convenient to implement.Recover under the situation of failure at photosphere then, the LSP with small grain size is that unit recovers on the IP/MPLS layer again, and this has can take into account validity and the flexibility that small grain size is recovered, thereby has improved the recovery efficient to business, reduces professional interruption rate.This tactful shortcoming is owing to preferentially recover at bottom, can not find out the service attribute of high level, the difficult business recovery of realizing based on QoS.

1. the contrast of resource utilization:

Fig. 7 has provided under Mesh-Torus and the NSFNet topology, the dynamic blocking performance with the offered load variation of the present invention and other surviving policy in the IP/MPLS over WDM network.We can find out from figure; The present invention has the close dynamic blocking performance of photoreactive layer sharing channel protection OSPP; And when offered load is heavier; The advantage of the higher resource utilization of the present invention and OSPP is clearly, especially for the less relatively NSFNet physical topology of network available resources (λ＞400Erlang).This is to carry out the sharing channel protection because the present invention has adopted at first at photosphere, is identical with OSPP in this.Do like this and guaranteed that the present invention has high bandwidth availability and protects switching operation fast and less signaling manipulation.

Unite in addition recovery policy IBUR and ITDR generally have than Combined Protection strategy IDPP and ISPP high resource utilization, especially IBUR when offered load is not very heavy (for Mesh-Torus topology, λ＜700Erlang; For NSFNet topology, λ＜400Erlang), have quite high resource utilization.

Fig. 8 has provided under Mesh-Torus and the NSFNet topology, the present invention and other surviving policy dynamic blocking performance under heterogeneous networks link failure frequency in the IP/MPLS over WDM network.When the link failure frequency aggravation of network; Resource utilization of the present invention increases on the contrary; This is because frequent link failure can cause the available resources of network to increase relatively equally; Thereby make network can respond (Accommodate) more newly arrived LSPs connection request, thereby reduced the blocking rate of network.

We it can also be seen that from Fig. 8, and under various network link failure frequency, the present invention has photoreactive layer and shares the close blocking performance of circulation passage protection OSPP.Under the NSFNet topology, the present invention and OSPP have resource utilization preferably under various network link failure frequency.And under the abundant relatively Mesh-Torus topology of network available resources, blocking performance of the present invention then is worse than IBUR, ITDR and ISPP, especially at network failure when not being very frequent.IDPP is in these surviving policy of reference in addition, and no matter frequently whether network failure still has the poorest resource utilization, and can to take too much resource relevant protecting with IDPP for this.

2. the contrast of existence efficient:

Fig. 9 has provided under Mesh-Torus and the NSFNet topology, the present invention and the existence efficient of other surviving policy under the heterogeneous networks load in the IP/MPLS over WDM network.Simulation result shows that the present invention has had the protection efficient that is similar to IDPP, or even the protection efficient that is higher than IDPP is (for the NSFNet topology; When λ＞600Erlang; To Mesh-Torus topology, when λ＞210Erlang, the present invention has had the existence efficient that is higher than IDPP).This makes the present invention except having the high resource utilization of OSPP; Advantage is switched in protection fast; Also had high existence efficient; Have the protection efficient that manys higher than OSPP simultaneously, this mainly is because the present invention has also combined IBUR and the ITDR high recovery efficient that dynamic recovery brought at the IP/MPLS layer simultaneously.

Figure 10 has provided under Mesh-Torus and the NSFNet topology, the present invention and the existence efficient of other surviving policy under different single link failure frequencies in the IP/MPLS over WDM network.We find from figure, and when the link failure frequency of network reduced, existence efficient of the present invention was the gesture of rising, and has had the recovery efficient close with ITDR, especially for the Mesh-Torus physical topology.Simulation result has also shown simultaneously, and recovery policy IBUR and ITDR have under all network link failure frequencies than the high existence efficient that manys of protection strategy.

Can know through above-mentioned correction data:

Comprehensive more various Combined Protection strategies and associating recovery policy, and the existence performance of the present invention that has combined the dynamic recovery of protection of photosphere sharing channel and IP/MPLS layer.In all protections and recovery policy, under various network load and failure-frequency, OSPP still has best resource utilization, especially under topology (like the NSFNet) situation that offered load is heavy, network average nodal degree is low.The present invention has the resource utilization that is similar to OSPP, and this is because the present invention has combined the characteristics of optical layer protective.Associating recovery policy IBUR, ITDR have than Combined Protection strategy IDPP, resource utilization that ISPP is good.Aspect existence efficient, the performance of associating recovery policy IBUR and ITDR is much better than Combined Protection strategy IDPP and ISPP.Existence efficient of the present invention is only second to ITDR, especially heavy, link failure at offered load be not very frequent and the situation of the topology (like Mesh-Torus) that network average nodal degree is big under.

Comprehensively it seems; The present invention has resource availability and existence performance preferably; This be since its combine the protection of photosphere sharing channel fast, coarsegrain and resource availability, and flexibility that dynamically recovers in IP/MPLS layer small grain size and higher recovery efficient.

Above-described embodiment of the present invention does not constitute the qualification to protection range of the present invention.Any modification of within spirit of the present invention and principle, being done, be equal to replacement and improvement etc., all should be included within the claim protection range of the present invention.

Claims

1. an IP/MPLS over WDM network protection restoration methods is characterized in that, may further comprise the steps:

The attribute of the fault optical channel in the detection failure link;

Whether if said fault optical channel is the work optical channel, then further detecting said work optical channel has corresponding protection optical channel;

If said work optical channel has corresponding protection optical channel, then the LSPs business on the said work optical channel is transferred on the corresponding protection optical channel, and discharged the resource of said work optical channel; If said work optical channel does not have corresponding protection optical channel, then all the LSPs business on the said work optical channel are carried out heavy-route at the IP/MPLS layer;

If said fault optical channel is the protection optical channel, then discharge the resource of said protection optical channel.

2. IP/MPLS over WDM network protection restoration methods as claimed in claim 1 is characterized in that the step of all the LSPs business on the said work optical channel being carried out heavy-route at the IP/MPLS layer comprises:

The failure message of LSPs on the said work optical channel is sent to the start node of each said LSPs with signaling method;

3. like claim 1 or 2 described IP/MPLS over WDM network protection restoration methods, it is characterized in that, after the IP/MPLS layer carries out heavy-route to all the LSPs business on the said work optical channel, further may further comprise the steps:

If said LSPs is carried out the heavy-route success, then set up and recover LSPs, the business of the LSPs on the said work optical channel is transferred on the said recovery LSPs;

If said LSPs is carried out the heavy-route failure, then interrupt the business of said LSPs, after the business recovery of wait IP/MPLS layer is accomplished, discharge the resource of said work optical channel.

4. IP/MPLS over WDM network protection restoration methods as claimed in claim 1 is characterized in that, discharges before the resource of said protection optical channel, also comprises step:

Judge whether said protection optical channel has the business of LSPs to move;

If there is the business of LSPs to move, then interrupt the business of the LSPs on said protection optical channel.

5. IP/MPLS over WDM network protection restoration methods as claimed in claim 1 is characterized in that, before the fault optical channel in the detection failure link, further may further comprise the steps:

Each said work optical channel is set up the protection optical channel;

If set up the success of protection optical channel, then the safe condition of said work optical channel is labeled as and protects;

If set up the failure of protection optical channel, then the safe condition with said work optical channel is labeled as not protection.

6. IP/MPLS over WDM network protection restoration methods as claimed in claim 5 is characterized in that, whether detect said work optical channel has the step of corresponding protection optical channel to comprise:

Detect the safe condition of said work optical channel;

7. IP/MPLS over WDM network protection restoration methods as claimed in claim 6 is characterized in that, is the protection optical channel if judge said fault optical channel, then further carries out following steps:

The safe condition of the work optical channel that said protection optical channel is corresponding is labeled as not protection.

8. an IP/MPLS over WDM network protection recovery system is characterized in that, comprising:

Channel detecting module is used for the attribute of the fault optical channel of detection failure link;

Protection attribute detection module is used for when said fault optical channel is the work optical channel, and whether detect said work optical channel has corresponding protection optical channel;

Professional shift module is used for when said protection attribute detection module detects said work optical channel corresponding protection optical channel is arranged, the business of the LSPs on the said work optical channel being transferred on the corresponding protection optical channel;

The heavy-route module is used for when said protection attribute detection module detects said work optical channel and do not have corresponding protection optical channel, at the IP/MPLS layer business of all LSPs on the said work optical channel being carried out heavy-route;

The resource release module is used to discharge the resource of said fault optical channel.

9. IP/MPLS over WDM network protection recovery system as claimed in claim 8 is characterized in that said heavy-route module comprises:

The signalling trouble module is sent to the failure message of the LSPs on the said work optical channel start node of each said LSPs with signaling method;

The heavy-route Executive Module carries out heavy-route at the IP/MPLS layer to the said LSPs that receives failure message.

10. like claim 8 or 9 described IP/MPLS over WDM network protection recovery systems, it is characterized in that further comprise: LSPs sets up module and service disconnection module;

Said LSPs sets up module when said heavy-route module is carried out the heavy-route success to said LSPs, sets up and recovers LSPs, and said professional shift module is transferred to the business of the LSPs on the said work optical channel on the said recovery LSPs;

When said service disconnection module is carried out the heavy-route failure in said heavy-route module to said LSPs, interrupt the business of said LSPs;

Said resource release module discharges the resource of said work optical channel after the business recovery of IP/MPLS layer is accomplished.