CN1588883A - Network protective method based on multiple volume preset protective ring - Google Patents

Abstract

A method for providing protection to network with preset protect loops based on multiple volumes is to first of all adopt a linear mapping model to minimum the general volume or total cost of the network backup resource in terms of 100% recovery of the network to optimize the network resource configuration, then to adopt a modified algorithm to adjust the backup resource of each loop link to protect the preset property of loop, among which, the said preset protection loop based on multiple volumes means the preset protection rate of two or over backup resources are permitted on each loop link.

Description

Preset protection ring network protection method based on multicapacity

Technical field

The present invention relates to a kind of network protection method, specifically is a kind of preset protection ring network protection method based on multicapacity.Be used for network communications technology field.

Background technology

Along with the continuous development of Internet and network technology, more and more higher requirement has been proposed for the survivability and the reconfigurability of network.Based on network ring topology and mesh network topology have proposed many protection recovery policies.(as BLSR) can realize protecting fast recovery (about 50ms) in ring network, but needs to reserve 100% resource backup at least.In mesh network; adopt shared path protecting method can realize very high resource utilization (as being less than 70%); but need complicated signaling during owing to fault recovery; and after fault takes place; the switch of middle each node needs configuration in real time, can't realize that therefore protection fast recovers as ring network.Protection scheme based on preset protection ring has possessed ring network protection and two advantages of the efficient resource utilization of mesh network fast simultaneously, so preset protection ring is a kind of ideal scheme that improves network survivability.Preset protection ring can be applied to diverse network, as IP, and MPLS, SDH, ASON, WDM network.

There is three types preset protection ring at present: link protection preset protection ring, Node Protection preset protection ring and stream protection preset protection ring.Discovery by literature search, people such as G.Shen have delivered one piece of article on the 21st the 8th phase of volume of the selected topic magazine (i.e. " IEEE JSAC ") of communicating by letter of U.S. electric and Electronic Engineering Association: the preset protection ring that expands to the route segment protection is used for the protection recovery (" Extending thep-cycle concept to path segment protection for span and node failure recovery ") of link and node failure.This article has been introduced the notion of stream protection preset protection ring, and such preset protection ring can be protected all business on the circle link chord link of preset protection ring, also can protect the Business Stream that has different intersection points more than two with preset protection ring at least.These three kinds of preset protection rings are referred to as traditional preset protection ring, and they have a common ground, and that is exactly must the identical resource backup of configuration on each bar circle link of each preset protection ring, and this restriction has brought certain resource redundancy.

Summary of the invention

The objective of the invention is to overcome the deficiency and the defective of existing traditional preset protection ring technology, proposed a kind of preset protection ring network protection method, make it obtain higher network resource utilization based on multicapacity.

The present invention is achieved by the following technical solutions; the present invention uses the preset protection ring based on multicapacity to provide protection as network; guaranteeing under the network 100% recoverable prerequisite; at first adopt linear programming model; make total amount or total cost minimum of the resource backup of network; reach the purpose of optimizing the Internet resources configuration; next adopts a correction algorithm to adjust the preset feature of the resource backup of every circle link with the protection preset protection ring; wherein said preset protection ring based on multicapacity is meant on each bar circle link the preset protection ring that allows two kinds of configurations or two or more resource backup; can reduce the resource redundancy degree, improve utilization rate of network resource.The linear programming solution adopts ripe algorithm, can be simple algorithm, or the Karmarkar algorithm, perhaps finds the solution with the linear programming software kit.

1, described linear programming model, establishment step is as follows:

(1) collects network parameter

S is the link set of network;

P is the preset protection ring set of all preliminary elections in the network;

c _kIt is the cost of unit bandwidth among the link k;

D _iBe all node pair sets that are subjected to failure effect;

d ^rBe the number of node to unit bandwidth professional between the r;

When link i lost efficacy, if preset protection ring j can not protect stream r, then γ _{I, j} ^rBe 0, if inefficacy link i then is 1, otherwise is 2 not only in Working service r but also in circle j;

If the link k among the circle j is the inefficacy link i that is used for protecting among the Working service stream r, then δ _{I, j, k} ^rBe 1, otherwise be 0;

(2) defined variable

n _{J, k}Be the final variables of linear programming model, the unit bandwidth number of the circle link k on the expression circle j;

n _{I, j} ^rBe the intermediate variable of linear programming model, expression was enclosed maximum unit bandwidth numbers that j needs when the link i on the Working service r lost efficacy.(annotate: when protection recovers this Working service r; if some link among the circle j does not use; then needn't be on these links the configuration backup resource; if therefore allow configuration two kinds or two or more resource backups on each bar circle link of preset protection ring; then can reduce the redundancy of Internet resources, improve utilization rate of network resource.This is the main distinction based on multiclass degree preset protection ring and traditional preset protection ring of the present invention.)

(3) set up the survivability constraint

$\underset{j\∈P}{\mathrm{\Σ}}{\mathrm{\γ}}_{i,j}^r\·n_{i,j}^r\≥d^r---\∀i\∈S;\∀r\∈D_t$

This survivability constraint has guaranteed the recovery of network failure service energy 100% when breaking down.

(4) set up bandwidth constraint

$\underset{r\∈D_t}{\mathrm{\Σ}}{n}_{i,j}^r\·{\mathrm{\δ}}_{i,j,k}^r\≤n_{j,k}---\∀i\∈S;\∀j\∈P;\∀k\∈S$

If this constraint representation link i breaks down at the place, and preset protection ring j is used to provide protection and recovers, and then encloses the bandwidth of the circle link k on the j and enough recovers for all failure services provide protection.

(5) set up target function

$\mathrm{Minimize\Σ\Σ}{c}_k{n}_{j,k}$

The total cost minimum of band width configuration on the multiclass degree P circle that this target function guarantees to try to achieve by linear programming model of the present invention.If c _kGet 1, then target function is represented the total amount minimum of resource backup.

By finding the solution top linear programming equation group, needing on each bar link of each preset protection ring to obtain the resource backup quantity that disposes.

2, described circle link backup resource correction algorithm is as described below:

On preset protection ring, the resource backup capacity is that 0 circle link definition is a virtual link.On preset protection ring, except empty limit, the circle link definition of resource backup capacity minimum is the minimum capacity link.Virtual link and minimum capacity link are divided into several sections to preset protection ring.In order to guarantee the preset feature of preset protection ring, the multicapacity preset protection ring must satisfy one and preset constraint, and that is exactly for the maximum resource backup capacity in these limits of all necessary configuration, all limits on each preset protection ring section.Algorithm is adjusted each preset protection ring, and realizes in two steps:

(1) finds out virtual link and the minimum capacity link that this encloses, promptly found and cut apart all preset protection ring sections that obtain;

(2) find heap(ed) capacity on each preset protection ring section respectively, and all limits on this circle section are all disposed heap(ed) capacity on this section.

Compare with the network protection method of traditional preset protection ring; adopt preset protection ring network protection method of the present invention; in the quick protection recovery characteristics that keeps traditional preset protection ring; under different network topologies and service distribution, can improve the network resource utilization of 4%-60%.

Description of drawings

Fig. 1 is a multicapacity preset protection ring schematic diagram of the present invention

Fig. 2 finds the solution the resource backup capacity configuration schematic diagram of the multicapacity preset protection ring that obtains for linear programming model of the present invention

Fig. 3 is the resource backup capacity configuration schematic diagram of the multicapacity preset protection ring that obtains after the circle link backup resource correction algorithm adjustment of preset protection ring of the present invention

Embodiment

In order to understand technical scheme of the present invention better, execution mode is explained in detail below in conjunction with accompanying drawing.

Example 1

Looped network with one six node is the difference that example is come preset protection ring more of the present invention and traditional preset protection ring below, as shown in Figure 1.1 is the circle link of preset protection ring among Fig. 1; 2 is Working service among Fig. 1.Suppose to have in looped network two business, one is B-A-F-E-D, and another is B-C-D-E, and the bandwidth of two business all is 10.

Preset protection ring in traditional preset protection ring method is A-B-C-D-E-F-A.The resource backup of all links is identical on the preset protection ring, is 20.

In Fig. 1; if when Business Stream B-A-F-E-D lost efficacy; restoration path adopts B-C-D; this shows that the link k (be B-C or C-D) of circle among the j is that to be used for protecting inefficacy link i among the Working service stream r (being B-A-F-E-D) (be B-A, or A-F, or F-E; or E-D); that is to say, when k is B-C or C-D, δ _{I, j, k} ^rBe 1, k then is 0 when being other limit.Similarly, if Business Stream B-C-D-E lost efficacy, restoration path adopts B-A-F-E, then when k be B-A, or A-F, or during F-E, δ _{I, j, k} ^rBe 1, k then is 0 when being other limit.(can use the linear programming software kit by finding the solution above-mentioned linear programming equation group; as LP_Solver; CPLEX etc.); can obtain guaranteeing under the network 100% recoverable prerequisite; make under the situation of the total amount of resource backup of network or total cost minimum; need the resource backup quantity that disposes on each bar circle link of each preset protection ring, as shown in Figure 1.Can find that the protection of two business recovers the link D-E of arriving all useless, therefore, the resource backup on the link D-E can be 0, and promptly link D-E is a virtual link.Because in this example, preset constraints and satisfy, so needn't carry out circle link backup resource correction algorithm.In this example, adopt the network protection method of multicapacity preset protection ring to save 58.3% than the network protection method of traditional preset protection ring.

Example 2

Suppose that the resource backup capacity of every of preset protection ring circle link tries to achieve by linear programming method, as shown in Figure 2.Among Fig. 23 is preset protection paths in the preset protection ring.In Fig. 2, circle link D-E is a virtual link, and circle link A-B is the minimum capacity link.In order to guarantee the preset feature of preset protection ring, the resource backup capacity on the circle link need adopt correction algorithm adjustment.Be that all circle links between the preset protection ring section A-F-E all dispose the resource backup capacity of 2 units, all the circle links between the preset protection ring section B-C-D all dispose the resource backup capacity of 3 units.The configuration of the resource backup of the multicapacity preset protection ring that obtains is at last compared with the network protection method of traditional preset protection ring as shown in Figure 3, and the network protection method of multicapacity preset protection ring of the present invention can save 38.9%.

Claims (3)

1; a kind of preset protection ring network protection method based on multicapacity; it is characterized in that; use preset protection ring to provide protection as network based on multicapacity; under the prerequisite that network 100% can recover; at first adopt linear programming model; make total amount or total cost minimum of the resource backup of network; reach and optimize the Internet resources configuration; next adopts a correction algorithm to adjust the preset feature of the resource backup protection preset protection ring of every circle link; wherein, described preset protection ring based on multicapacity is meant on each bar circle link the preset protection ring rate that allows two kinds of configurations or two or more resource backup.

2, the preset protection ring network protection method based on multicapacity according to claim 1 is characterized in that, described linear programming model, and establishment step is as follows:

(1) collects network parameter

S is the link set of network, and P is the preset protection ring set of all preliminary elections in the network, c _kBe the cost of unit bandwidth among the link k, D _iBe all node pair sets that are subjected to failure effect, d ^rBe the number of node, when link i lost efficacy, if preset protection ring j can not protect stream r, then γ to unit bandwidth professional between the r _{I, j} ^rBe 0, if inefficacy link i then is 1, otherwise is 2 not only in Working service r but also in circle j; If the link k among the circle j is the inefficacy link i that is used for protecting among the Working service stream r, then δ _{I, j, k} ^rBe 1, otherwise be 0;

(2) defined variable

n _{J, k}Be the final variables of linear programming model, the unit bandwidth number of the circle link k on the expression circle j, n _{I, j} ^rBe the intermediate variable of linear programming model, expression was enclosed maximum unit bandwidth numbers that j needs when the link i on the Working service r lost efficacy;

(3) set up the survivability constraint

$\underset{j\∈P}{\mathrm{\Σ}}{\mathrm{\γ}}_{i,j}^r\·n_{i,j}^r\≥d^r$ i∈S；r∈D _i

This survivability constraint has guaranteed the recovery of network failure service energy 100% when breaking down;

(4) set up bandwidth constraint

$\underset{j\∈D_i}{\mathrm{\Σ}}{n}_{i,j}^r\·{\mathrm{\δ}}_{i,j,k}^r\≤n_{j,k}$ i∈S；j∈P；k∈S

If this constraint representation link i breaks down at the place, and preset protection ring j is used to provide protection and recovers, and then encloses the bandwidth of the circle link k on the j and enough recovers for all failure services provide protection;

(5) set up target function

Minimize∑∑c _kn _j，k

If the total cost minimum of band width configuration on the multiclass degree P circle that this target function guarantees to try to achieve by linear programming model is c _kGet 1, then target function is represented the total amount minimum of resource backup.

3, the preset protection ring network protection method based on multicapacity according to claim 1 is characterized in that, described circle link backup resource correction algorithm is as follows:

On preset protection ring; the resource backup capacity is that 0 circle link definition is a virtual link; on preset protection ring; except empty limit; the circle link definition of resource backup capacity minimum is the minimum capacity link; virtual link and minimum capacity link are divided into several sections to preset protection ring; in order to guarantee the preset feature of preset protection ring; the multicapacity preset protection ring must satisfy one and preset constraint; that is exactly for the maximum resource backup capacity in these limits of all necessary configuration, all limits on each preset protection ring section; algorithm is adjusted each preset protection ring, and realizes in two steps:

(1) finds out virtual link and the minimum capacity link that this encloses, promptly found and cut apart all preset protection ring sections that obtain;

(2) find heap(ed) capacity on each preset protection ring section respectively, and all limits on this circle section are all disposed heap(ed) capacity on this section.

Images