Embodiment
By with reference to following detailed description for exemplary non-limiting examples and figures, advantages and features of the invention and realize that method of the present invention is easier to understand.Yet the present invention can implement with multiple different form, and the embodiment that should not be construed as limited in this explaination.In addition, thus it will be completely and completely that these embodiment the disclosure are provided.And complete conveyed to those skilled in the art with design of the present invention, the present invention will only be defined by claims.In specification, identical label is indicated the parts of enjoying all the time.
Fig. 1 shows resource-based circle Protection Code and realizes block diagram.Mainly comprise three kinds of processing under the state: pre-configured state, normal operating conditions and malfunction.
Pre-configured state is meant the state of network before handling all service request, is used for enclosing calculating and sharing out the work and resource conservation.At first,, utilize circle searching algorithm 103 to find out all possible circle set 104 in the network, and obtain mesh circle set 106 simultaneously in conjunction with optionally enclosing length restriction condition 102 according to network topology 101.Wherein, the searching algorithm of circle set commonly used has breadth-first search (breadth first search) algorithm and Johnson algorithm etc.The mesh circle is at the name of mesh net.The computational methods of mesh circle are: to any link in the network topology, be input parameter, call dijkstra's algorithm one time with the head and the tail node of this link, try to achieve between two nodes this link shortest path by.This time short circuit by coupling together with this link, is promptly obtained a mesh circle.After the circle set was calculated and finished, this method was used didactic two step collocation methods 108 to choose one group of circle from available circle set 105 and mesh circle set 106 and is gathered as guard circle in conjunction with the link capacity information 107 of network topology 101 and topology.Then whole network capacity is divided into working capacity and protection capacity, distributes the working resource 109 of resource conservation 110 and its protection; And finish pre-configured process to the mesh net topology, form pre-configured back topology 111.Because the hypothesis network is uniformly,, enclose uplink has half on each direction capacity as the protection capacity so the capacity on every link equates that all the distribution of circle uplink capacity is similar to the two fibre two-way multi-section guard rings (BLSR) of SDH.Corresponding relation on the link between the working resource of resource conservation and its protection is stored in the resource record table of this end of link node, by this end of link node maintenance.The flow chart and the process description aftermentioned thereof of two step collocation methods.
So far, pre-configured state finishes, and network enters normal operating conditions and malfunction processing procedure.When network is in normal operating conditions, the processing procedure 112 of service request itself there is not particularity.Promptly, satisfy service request, finish professional foundation according to effective route and Wavelength assignment algorithm 113.When business reaches,, just can reach the professional purpose of protection, no matter and be static traffic or dynamic service as long as route is selected in available working capacity inside in the topology 111 of pre-configured back.
When network failure took place, by fault detect 114, network entered malfunction by normal operating conditions.The protection that the handling process of malfunction is divided into before the fault restoration switches 115, and the resource after failover process 116 and the fault restoration switches 117.Wherein failover process 116 is meant by artificial or method for distinguishing, repairs the process of faulty link.After the fault restoration, the network recovery normal operating conditions; It is in order to provide the working resource that effective protection initiates and the bridge joint process of resource conservation for the business on the faulty link at short notice that protection before the fault restoration switches 115; It is after fault restoration that resource after the fault restoration switches 117, before the network recovery fault takes place state the time, and the resource reversed process of doing for the couple state that guarantees the resource conservation of part circle uplink.This is to provide the preparation of doing of quick protective switch for network failure next time.Switch for twice need defer to two the step collocation methods 108 suit mutually switch the rule 118.The process chart of malfunction and process description aftermentioned thereof.
Fig. 2 illustrates the flow chart of two step collocation methods among Fig. 1.Two step collocation methods are a kind of heuritic approaches, are used for selecting one group of circle in two steps from all available circles of network, for every link of network provides protection.We introduce some call parameters of algorithm operation before describing its basic step.Suppose that link capacity all is C in the uniform network.Suppose that N represents the set of all nodes in the network, S represents the set of all links in the network, s
X, yA link between representation node i and the j, x, y ∈ N.Set P={p
1, p
2, p
3..., p
nThe set of a series of P of representative circle, wherein n represents the number that P encloses in this set.For i P circle p
i, definition
Represent the number of the ring uplink that this P circle comprised,
Represent this P to enclose the number of the gap-bridging link that is comprised.Definition
Be effective weight of single P circle, be used for reflecting capacity that the P circle can protect what.According to the basic definition of P circle,, can protect one times working capacity, and, then can protect the working capacity of twice for gap-bridging link for the ring uplink.Therefore, for some P circle p
i, the computing formula of its effective weight is:
Wherein,
Expression is for specific P circle p
i, link s
X, yWeighted value, work as s
X, yDuring for the ring uplink of this P circle,
Work as s
X, yDuring for the gap-bridging link of this P circle,
Otherwise
Simultaneously, definition
Be some P circle p
iVolumetric efficiency, be used for reflecting the protection efficient of single P circle, the ratio of promptly protected capacity and protection capacity, then
Can be defined as:
Wherein, | p
i| represent the size of this P circle, equal the number of this P circle ring uplink, promptly
After circle set search, we can obtain available circle set P.After passing through the one-time calculation to full mesh topology according to mesh circle computational methods in addition, we can obtain mesh circle set NP.We are not comprised the available circle set P of mesh circle remove the common factor of P and NP from P after
1, i.e. P
1=P-P ∩ NP.We are referred to as available substantially circle set.
The first step of two step collocation methods is the available substantially circle set P that never comprise the mesh circle
1In select one group of pairwise orthogonal and the high circle of volumetric efficiency provides effective protection for most of link, second step was then utilized the circle of scale minimum in the network---the mesh circle is not for providing the link assignment resource conservation of protection, to realize the covering fully to network link.Two the step collocation methods performing step as shown in the figure:
In step 201, algorithm begins.
Step 202 to step 206 belongs to first step circle layoutprocedure, and its function is: from available substantially circle set P
1In select one group of pairwise orthogonal (do not have overlap link) available circle network link is carried out covering first time.
In
step 202, the initialization network topology all is initialized as available working resource with all resources; And, calculate P according to the current resource situation of the topological sum of network
1In the volumetric efficiency of each available circle
A circle
The ratio that can reflect when adopting this circle that protection is provided new work resource in the network and newly-increased resource conservation;
In step 203, find out set P
1In the circle of volumetric efficiency maximum as the circle of this selection, if the volumetric efficiency of a plurality of circles is all identical, so just select many one of active link, if identically more then select one arbitrarily;
In step 204, be that this circle that chooses distributes resource conservation, and its working resource that can protect is protected for being subjected to this circle to upgrade under it formal notation of end of link node place record sheet.The resource conservation distribution is half of every circle uplink capacity, i.e. C/2.Capacity is that symmetrical complement distributes on two-way link, is similar to the capacity allocation mode of BLSR.Record sheet is preserved by two end points of link and is safeguarded that the structure of record sheet will be introduced in detail at further part.If the circle uplink of this circle overlaps with the gap-bridging link of original circle, the record sheet that then distributes the corresponding protection resource and upgrade this gap-bridging link end points place is protected by the circle of current selection; If the gap-bridging link of this circle overlaps with the circle uplink of original circle, then capacity allocation is constant on this link, does not upgrade record sheet; If the gap-bridging link of this circle overlaps with the gap-bridging link of original circle, then capacity allocation is constant on this link, upgrades record sheet for being subjected to that circle protection of length the shortest (or jumping figure is minimum);
In step 205, judge whether that the all-network resource divided and finish (promptly all links all are marked in the protection range of a circle).If then enter step 210; Otherwise, continue step 206;
In step 206, upgrade topology, all links of having divided resource conservation in the circle of this selection are left out from network topology, i.e. every circle uplink.From set P
1In remove disabled circle in this circle selected and the topology after renewal, promptly having the circle uplink of or one or more is to have deleted the circle of link.Judge set P
1In whether have available circle, if having, get back to step 203; If set P
1In do not had available circle, then recover network topology, i.e. links of deletion before all.Each node is preserved circle protection record sheet, enters the second step layoutprocedure.
Step 207 to step 209 belongs to the second step circle layoutprocedure, and its function is: select one group of available circle from mesh circle set NP network link is realized covering fully.They each other and and the selected circle of the first step between can exist and reuse link.
In step 207, find out set and comprise the maximum circle of also unallocated link among the NP as this selected circle.If the unallocated number of links that a plurality of circles comprise is identical, few one of choosing circle length so is if identically more then select one arbitrarily;
In step 208, be that this mesh circle that chooses distributes protection and working resource, and preserve the nodes records table and its working resource that can protect is labeled as is subjected to this circle protection.The capacity allocation mode is identical with step 204, and resource conservation is half of every circle uplink capacity.If there is identical circle uplink in this circle with the circle that the first step has been selected, then this link capacity distribution is constant, and the record sheet of link end points is constant; If there is identical circle uplink in this circle with second circle selected of step, then this link capacity distribution is constant, this circle is added in the record sheet of link end points so far; If the circle uplink of this circle overlaps with the gap-bridging link that the first step has been selected to enclose, then distribute the corresponding protection resource, and the record sheet that upgrades this gap-bridging link end points place is protected by the circle of current selection;
In step 209, judge whether that the all-network resource divided finish (promptly all links are all at least in the protection range of a circle).If then continue step 210; Otherwise, from mesh circle set NP, remove the circle of this selection, jump to step 207.
In step 210, algorithm finishes.
Two groups of available circles can be obtained through this algorithm, all standing can be realized network link.Wherein, by first group of circle pairwise orthogonal selecting among the set P1 (not having the circle uplink that overlaps), these circles all are that protection efficient is high and link that comprise is many, coverage is wider.Second group of circle being selected among the NP by set do not require pairwise orthogonal, do not require yet with first group in the circle quadrature.Second group of circle volumetric efficiency all is 1, and the scale of circle is all very little.Be of value to shortening when fault takes place and protect switching messages, also be of value to the fully covering of realization simultaneously link around the time that ring transmits.In second group of available circle, there is not gap-bridging link in the mesh circle, but a plurality of circle may have the circle uplink of repetition.At this moment, the resource conservation of circle uplink can be a plurality of circle and reuses (we claim that such link is for reusing link).Therefore, write down the circle at this link place, switch so that when fault, carry out corresponding protection with regard to the end node that needs each bar link.On circle during other link occurs fault, two nodes of reusing on the link can be switched to resource conservation on the corresponding circle according to the fault signaling, and when reusing link occurs fault, only need be just passable to the circle being responsible for its recovery at the both link ends switching services of naming a person for a particular job; And in first group of available circle, owing to be the relation of quadrature between the circle, so can there not be the circle uplink of reusing.And if the gap-bridging link that link is a plurality of circles in order to reduce guard time, can be stipulated that circle protection by length the shortest (or jumping figure is minimum) of this gap-bridging link at this; And between second group and first group of circle the situation that uplink is reused may appear also enclosing.At this moment we stipulate, break down if circle is gone up other links (the non-link of reusing), then utilize the resource conservation protection in this circle to switch; If reuse link occurs fault, then utilize the resource conservation of first group of circle to finish protection and switch.
Fig. 3 illustrates an application example figure of two step collocation methods.Provided 4 available circles among the figure, wherein, p
1And p
2Be based on the circle set P that factor such as length calculates respectively
1Maximum and time big available circle of middle volumetric efficiency; Np
1And np
2Belong to mesh circle set NP.We have
By the configuration of first step circle, p
1And p
2Successively chosen.p
1Provide protection for its circle upward reaches gap-bridging link, comprise link s
1,2And s
2,3p
2Provide protection for its circle upward reaches gap-bridging link, comprise link s
1,4Respective link can be divided resource conservation automatically; The end points of respective link can be preserved the corresponding relation of this link and guard circle in record sheet.Suppose at this moment only to have link s in the network
2,4And s
3,4Unallocated resource is also distributed available guard circle, then will trigger the layoutprocedure in second step.After second step, placement algorithm finished, link s
3,4Will be by mesh circle np
2Protection; Link s
2,4As circle np
1And np
2Shared link, will by the circle np
1And np
2In any one protection (may be prescribed as circle that the shortest circle of jumping figure).At this moment, link s
2,4And s
3,4On resource will divide equally according to the mode of half work, half protection.s
3,4End points with np
2Be recorded as the guard circle of this link.Because s
2,4Be shared link, its end points will write down circle np simultaneously
1And np
2Select in the actual reversed process.And the circle np of second step configuration
1, np
2Circle p with the configuration of the one 1 step
1, p
2Between have the situation of shared link equally.Our regulation: if having shared link between second circle chosen of step, then this shared link can be implemented protection by a plurality of circles; If second step was chosen and the one 1 circle chosen of step between have shared link, then provide protection, so only preserve the corresponding relation with the latter in the record sheet at these link end points places by the latter.
The working channel numbering is W (x, y, 0/1) on the link, and wherein x represents link, and y represents the order numbering of this working channel on this link, and 1 is expressed as this channel provides the circle of protection to belong to the two first group of circle set that goes on foot in the collocation methods, and 0 expression does not belong to.W (s for example
1,2, 2,1) and expression link s
1,2In the 2nd working channel be subjected to certain circle protection in the set of first group of circle.Protection channel number mode on the link is that (z), wherein x represents link to P for x, y, and y represents the order numbering of this protection channel on this link, and z represents this protection channel place circle.P (s for example
1,2, 1, p
1) expression link s
1,2In the 1st the protection channel, the circle p
1In.The channel of mentioning below more than reaching all is meant two-way channel.It should be noted that the corresponding relation of two step collocation methods at good resource of the node configuration of reusing both link ends and guard circle.In figure, node 2 and node 4 are np
1With np
2Reuse link s
2,4End points; Node 1 and node 4 are np
1And p
2Reuse link s
1,4End points.With node 4 is example, and the work resource conservation record sheet of its maintenance is as shown in table 1:
The work resource conservation of safeguarding in table 1 node 4
In the last table, y is a variable
P (s
1,4, y, p
2) and P (s
1,4, y, np
1) refer to p together
2And np
1Shared link s
1,4On resource conservation.Work as np
1Go up and remove s
1,4And and p
1, p
2During outer other link failures of the link of sharing, i.e. link s
2,4During fault, node 1 and node 4 are judged can be by np
1Perhaps np
2Protection.If select np
1, s
1,4On resource conservation will be used as np
1Protection.Work as p
2Go up and remove s
1,4During outer other link failures, node 1 and node 4 judge it is p
2So protection is with s
1,4On resource conservation as p
2Protection.When reusing link, i.e. s
1,4During fault, node 1 and node 4 are judged still by p by tabling look-up
2Protection is provided.In like manner, s
2,4Be np
1And np
2Shared link.If s
3,4Break down, node 3 and node 4 are np with judgement
2Protection is also used s
2,4On resource conservation.If np
1Non-shared link of middle existence.When this link occurs fault, its end node will be tabled look-up judges it is np
1Protection.Will be s
2,4On resource conservation as np
1Protection.And work as s
2,4When itself breaks down, with s
1,4The processing mode difference of fault, node 2 and node 4 will be through consultation, and working resource is switched to np
1Or np
2In any one can.
Fig. 4 shows among Fig. 1 operate as normal period, and certain is the link capacity user mode in network constantly.Link capacity is divided according to the capacity division rule of each bar link in the network, and half of all told 406 of promptly enclosing uplink is working capacity 404, and second half is a protection capacity 405; All told 409 all can be used as working capacity and divides on the gap-bridging link.Wherein, load 402 is parts of having used in the working capacity 404 on the circle uplink, and idle capacity 401 is the parts that are not used as yet in the working capacity 404 on the circle uplink.Load 408 is parts of having used in all told 409 on the gap-bridging link, and idle capacity 407 is the parts that are not used as yet in all told 409 on the gap-bridging link.That of maximum in the maximum that maximum required protection capacity 403 equals to enclose uplink load 402 and peaked half these two value of gap-bridging link load 408.
The circle guard method that the present invention the proposes request process of managing business in network course of normal operation and mesh network is basic identical; when business reaches; as long as route is selected in working capacity inside available in topology; just can reach the professional purpose of protection, no matter and be static traffic or dynamic service.Because in this circle guard method design, the working capacity on each section of the whole network (link) all equates there is not prediction work traffic intensity matrix, do not optimize the configuration of working capacity and protection capacity according to the working capacity distribution pattern.So in professional routing procedure, need to consider to adopt suitable routing algorithm, efficiently utilize Internet resources, realize lower service blocking rate.Several routing algorithms commonly used have the shortest jumping routing algorithm (Shortest-HopRouting), minimum load routing algorithm (Least-Load Routing), maximum residual routing algorithms (Most-Free Routing) etc., the particular content of algorithm is not described herein at this.
Fig. 5 shows the error protection flow chart under the malfunction among Fig. 1.
In step 501, the end-point detection of faulty link starts the circle protection to the link failure that self connects;
In step 502, detect the work resource conservation record sheet of this link of link terminal point inquiry of link failure.And judge whether by available substantially circle protection.If flow process enters step 508, otherwise, step 503 continued;
In step 503, the link terminal point that detects link failure prolongs each circle of chain road direction on the guard circle and goes up node and send the protection switching messages (SwitchMessage) of carrying this coil structures information;
In step 504, the node on this guard circle circle receives the protection switching messages;
In step 505, in case the node on the circle receives the protection switching messages, just dispose the cross-connect matrix of this node according to message, return to the corresponding acknowledge message of end points (Confirm Message) of faulty link then;
In step 506, the end points of faulty link receives and waits for the affirmation message that all nodes return;
In step 507, the end points of faulty link judges whether to receive this circle and goes up the affirmation message that all nodes return.If continue step 508; Otherwise continue to wait for, return step 506;
In step 508, the end points of faulty link is finished the switching services process according to the corresponding relation of switching that inquires before separately.
In step 509, switch successfully after, the end points of faulty link sends the protection channel notification to this each node of switching on the circle that takies, notifies the protection channel on their this circles occupied;
In step 510, fault treating procedure.
In step 511, after troubleshooting finishes, affected business will be switched on the former working channel again again.Idle condition is replied in resource conservation.Judge the available substantially circle that whether is of this fault employing.If flow process enters to step 517; Otherwise, continue step 512;
In step 512, switch by this protection and to initiate node and prolong each circle of chain road direction on the guard circle (mesh circle) of this use and go up node and send the resource switching messages once more;
In step 513, node receives the resource switching messages on the circle;
In step 514; after node receives the resource switching messages on the circle; inquire about the record sheet at this node place and with the resource conservation on the link of reusing of the available substantially circle of guard circle shared in this protection process and all first steps configuration; by disposing the cross-connect matrix of this node, be switched to again on the available substantially circle.Resource conservation with the available substantially circle circle uplink that guarantees first configuration set recovers couple state.Return to this protection then and switch the corresponding acknowledge message of initiation node;
In step 515, this protection is switched and is initiated the node reception and wait for the affirmation message that all nodes return;
In step 516, this protection is switched the initiation node and is judged whether to receive the affirmation message that last all nodes of this circle return.If continue step 517; Otherwise continue to wait for, return step 515;
In step 517, flow process finishes.
Though described embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art can make various distortion or modification within the scope of the appended claims in this area.