CN102186126B

CN102186126B - Special unicast multi-layer protective method based on load equalization in optical network

Info

Publication number: CN102186126B
Application number: CN201110110142XA
Authority: CN
Inventors: 王兴伟; 王宇; 黄敏
Original assignee: Northeastern University China
Current assignee: Northeastern University China
Priority date: 2011-04-29
Filing date: 2011-04-29
Publication date: 2013-11-06
Anticipated expiration: 2031-04-29
Also published as: CN102186126A

Abstract

The invention provides a special unicast multi-layer protective method based on load equalization in an optical network, belonging to the technical field of network communication. The method comprises the steps of establishing working LSP (Logical Signal Processor) for service request, establishing a protective LSP for service request, providing WDM (Wavelength Division Multiplex) layer protection for a heavy working load optical path, and releasing resources after the service is not used. In the invention, the application scope of the traditional special unicast multi-layer protective method can be extended; a plurality of constrain situations are considered when carrying out multi-layer protection; the recovering action and utilization ratio of the resource can be considered comprehensively, and due to the load equalization used for wavelength on a physical link and the load equalization used for bandwidth on the optical path, the quantity of the services affected when the physical links fail can be reduced as far as possible.

Description

The dedicated multi-layered guard method of the clean culture based on load balancing in a kind of optical-fiber network

Technical field

The invention belongs to networking technology area, be specifically related to the dedicated multi-layered guard method of the clean culture based on load balancing in a kind of optical-fiber network.

Background technology

Along with the high speed development of the Internet, people have proposed Secretary to capacity and the performance of communication system.Wavelength division multiplexing (Wavelength Division Multiplexing, WDM) technology can provide huge transmission capacity, satisfies Internet service to the demand of bandwidth.But, in case network failure occurs, will cause a large number of services to interrupt.Meanwhile, in order to reduce the network operation cost, improve the bandwidth resources utilance, transmission network is developed to IP over WDM double-layer structure by traditional IP over ATM over SDH/SONET overWDM multiple-layer overlapped structure gradually, and IP operation directly is carried on the WDM optical-fiber network.The ability of persistent service is provided when breaking down for improving IP over WDM network, need to provides protection mechanism at IP layer and WDM layer.

The dedicated multi-layered guard method of clean culture in traditional optical-fiber network; mostly only consider the dedicated multi-layered guard method of link failure under single restraint condition; its scope of application is narrower; do not consider the multiple constraint situations such as the constraint of optical transceiver number, sparse wavelength conversion constraint, do not consider the recovery amount of action that reduces when breaking down and the resource utilization that improves light path yet.

Summary of the invention

Problem for above-mentioned prior art existence, the invention provides the dedicated multi-layered guard method of the clean culture based on load balancing in a kind of optical-fiber network, the method is under the prerequisite of considering single link failure, the quantity of impaired business when breaking down by reducing as much as possible the light path of passing through this physical link and the number of services that reduces as much as possible its carrying, reducing physical link; Consider simultaneously and recover action and resource utilization, provide protection and attach most importance to operating load light path that WDM layer protection be provided for business at the IP layer in conjunction with the privacy protection mechanism under the clean culture environment.

In IP over WDM network, there are three kinds to control model, be respectively overlay model, peer-to-peer model and extended model.Guard method of the present invention is mainly for peer-to-peer model.

Network model can be described as oriented connected graph G _p(V, L, W), as shown in Figure 6.V wherein, L, W represent respectively the wavelength set of node set, physical link set and every physical link of network, | V|, | L|, | W| represents respectively nodes, physical link number and every physical link medium wave long number of network.

The constraints that the present invention considers mainly contains: the wavelength continuity constraint under the constraint of optical transceiver number, the conversion of sparse part wavelength, sparse part light splitting constraint are described below:

(1) optical transceiver number

Each network node has been disposed optical transmitter and the optical receiver of some, and the present invention supposes that the optical transmitter of same node is identical with the optical receiver number.

(2) wavelength conversion capability

Whether have wavelength conversion capability according to node, node can be divided three classes: without wavelength transfer capability node, complete wavelength conversion capability node, part wavelength conversion capability node.

In the present invention, for convenience, the wavelength conversion capability of unified conceptual description node with the wavelength conversion range is that the wavelength conversion range is 0 with the node label that does not have wavelength conversion capability, and the node wave length conversion range with complete wavelength conversion capability is | W|.

(3) light splitting ability

According to the power of light splitting ability, network node can be divided three classes: without light splitting ability MI (Multicast Incapable), complete light splitting ability, part light splitting ability.

The dedicated multi-layered guard method of the clean culture based on load balancing in optical-fiber network of the present invention comprises the steps: step (1), sets up working LSP (label switched path) for service request, and concrete steps are as follows:

Step (1.1), link cost is set

According to formula W _wcl=1 * α _wclThe link cost W of each wavelength transfer link is set _wcl

Wherein: α _wclThe grade factor for the wavelength transfer link;

According to formula

The link cost W of each logical links is set _ll

Wherein: b _t, b _w, b _p, b _rThe total bandwidth, bandwidth of operation, protection bandwidth and the user's bandwidth on demand that represent respectively this logical links; α _llBe the logical links grade factor;

According to formula

Logical node corresponding to each node is set to the link cost W of the admittance link of the corresponding all wavelengths node of this node _al

According to formula

The corresponding all wavelengths node of each node is set to the link cost W of the admittance link of its logical node _al

Wherein: t _t, r _t, t _a, r _aRepresent respectively the total optical transmitter number of this Nodes, total optical receiver number, available light transmitter number and available light receiver number;

α _alFor admitting the grade factor of link;

According to formula The link cost W of each wavelength span is set _wll

Wherein: w _w, w _pOperating wave long number and protection number of wavelengths in physical link under this wavelength span respectively;

α _wllThe grade factor for wavelength span;

| W| is the number of wavelengths in every physical link;

Step (1.2), pathfinding

Step (1.2.1), utilize dijkstra's algorithm to calculate one from v ' _sTo v ' _dShortest path, judge whether pathfinding success;

Wherein: v ' _sBe v _sLogical node, v _sBe source node;

v′ _dBe v _dLogical node, v _dBe destination node;

Step (1.2.2) is if service request is refused in failure, and method finishes;

Step (1.2.3) is if success continues execution in step (1.3); The LSP that herein obtains is a link set that is comprised of wavelength transfer link, logical links, admittance link, wavelength span;

Step (1.3), format LSP

For each link in LSP:

Step (1.3.1) is if for admitting link, explanation need to be set up a new light path, record all wavelengths link and wavelength transfer link thereafter, until next admittance link occurs, create a new light path according to the orderly link set that obtains so according to the order of sequence;

Step (1.3.2) does not process if be logical links;

Through format, LSP has become a set that only is made of logical links;

Step (1.4), Resources allocation

Step (1.4.1), for newly-built light path, the use state of the corresponding wavelength span of its process is set to " being used to light path "; Light path source node place available light transmitter number subtracts one; Light path destination node place available light receiver number subtracts one; Increase corresponding logical links on logical topology;

Step (1.4.2), upgrade successively the bandwidth usage of each logical links on the LSP path.

Step (2), be that service request sets up protection LSP, concrete steps are as follows:

Step (2.1), link cost is set

It is ∞ that the corresponding all wavelengths link of physical link of working LSP process and the link cost of logical links are set; The link cost of all the other each wavelength transfer links, logical links, admittance link and wavelength span is as follows:

Wherein: α _wclThe grade factor for the wavelength transfer link;

According to formula The link cost W of each logical links is set _ll

According to formula

According to formula

α _alFor admitting the grade factor of link;

According to formula

The link cost W of each wavelength span is set _wll

α _wllThe grade factor for wavelength span;

| W| is the number of wavelengths in every physical link;

Step (2.2), pathfinding

Step (2.2.1), utilize dijkstra's algorithm to calculate one from v ' _sTo v ' _dShortest path, judge whether pathfinding success;

Step (2.2.2) is refused service request if failure discharges the resource that working LSP takies, and method finishes;

Step (2.2.3) is if success continues execution in step (2.3);

Step (2.3), format LSP

For each link in LSP:

Step (2.3.1) is if for admitting link, explanation need to be set up a new light path, record all wavelengths link and wavelength transfer link thereafter, until next admittance link occurs, create a new light path according to the orderly link set that obtains so according to the order of sequence;

Step (2.3.2) does not process if be logical links;

Through format, LSP has become a set that only is made of logical links;

Step (2.4), Resources allocation

Step (2.4.1), for newly-built light path, the use state of the corresponding wavelength span of its process is set to " being used to light path "; Light path source node place available light transmitter number subtracts one; Light path destination node place available light receiver number subtracts one; Increase corresponding logical links on logical topology;

Step (2.4.2), upgrade successively the bandwidth usage of each logical links on the LSP path.

Step (3), the operating load light path of attaching most importance to provide the protection of WDM layer:

When set up working LSP and protection LSP for service request after, check successively working LSP each logical links (every logical links all corresponding a light path) of process, if its load has surpassed the threshold value of appointment And the protection of WDM layer is not provided, and for this light path creates a protection light path, the protection light path need to be separated with its physical link so; The source node that makes this heavy industry make the load light path is v _a, destination node is v _b, concrete steps are as follows:

Step (3.1), link cost is set

The link cost that heavy industry is made the corresponding all wavelengths link of physical link of load light path process is set to ∞;

The link cost of all logical links is set to ∞;

According to formula

The link cost of all the other wavelength spans is set;

According to formula V ' is set _aAll go out edge joint and receive the link cost of link;

According to formula

V ' is set _bAll enter edge joint and receive the link cost of link;

All the other admit the link cost of link to be set to ∞;

Wherein: v ' _aThe source node v of the operating load light path of attaching most importance to _aLogical links;

v′ _bThe destination node v of the operating load light path of attaching most importance to _bLogical links;

Step (3.2), pathfinding

Step (3.2.1), calculate one with dijkstra's algorithm and connect v ' _aAnd v ' _bThe path of Least-cost, judge whether the pathfinding success;

Step (3.2.2) is if failed, and the WDM layer is protected unsuccessfully, and method finishes;

Step (3.2.3) continues execution in step (3.3) if success is made the load light path with this heavy industry and is labeled as " the WDM layer is protected " state;

Step (3.3), Resources allocation

Protection light path source node place available light transmitter number subtracts one; Light path destination node place available light receiver number subtracts one; Each wavelength span use state of protection road process is set to " being used to protection ".

Step (4), releasing resource when business is left away, concrete steps are as follows:

Step (4.1), successively discharge working LSP and protection LSP the bandwidth that takies on each logical links of process;

Step (4.2), for WDM layer protection is provided but operating load lower than

Logical links, delete its protection road; Be masked as " the WDM layer is not protected " state; The operating position that each wavelength span of protecting the road process is set is " using ";

Wherein:

Be a threshold value of the operating load appointment of light path,

Q_{LP}^{L} < Q_{LP}^{H};

Step (4.3), be 0 logical links for dedicated bandwidth, delete this logical links; The operating position that each wavelength span of light path process is set is " not using "; Light path source node place optical transmitter number adds one; Destination node place optical receiver number adds one.

The dedicated multi-layered guard method beneficial effect of the clean culture based on load balancing in optical-fiber network of the present invention: 1, can expand the range of application of the dedicated multi-layered guard method of traditional unicast, consider a plurality of restraint conditions when carrying out the multilayer protection; 2, consider recovery action and resource utilization, the working load of bandwidth is balanced on the equilibrium of wavelength working load and light path on physical link, affected number of services when with the minimizing of trying one's best, the physical link fault occuring; 3, when the operating load light path of attaching most importance to provides the protection of WDM layer, two operating load threshold values reduce because the jitter phenomenon that business is left away and caused by arranging.

Description of drawings

Fig. 1 is that network configuration is by the schematic diagram of multiple-layer overlapped to two-layer evolution;

Fig. 2 is the schematic diagram of overlay model;

Fig. 3 is the schematic diagram of peer-to-peer model;

Fig. 4 is the physical topology schematic diagram of (physical topology N) for example;

Fig. 5 is the schematic diagram of wavelength hierarchical diagram corresponding to physical topology N (wavelength hierarchical diagram G);

Fig. 6 is the schematic diagram of network model;

Fig. 7 is the schematic diagram of network node;

Fig. 8 is the wavelength hierarchical diagram;

Fig. 9 is basic multilayer auxiliary view;

Figure 10 has added the multilayer auxiliary view of admitting after link;

Figure 11 is the overview flow chart based on the dedicated multi-layered guard method of clean culture of load balancing in optical-fiber network;

Embodiment

Below in conjunction with accompanying drawing, the dedicated multi-layered guard method of the clean culture based on load balancing in optical-fiber network of the present invention is described in further detail.

One, optical-fiber network basic platform

1 IP over WDM network overview and key technology thereof

1.1WDM technology

Growing continuously and fast of mobile service, the 3G emerging service is saved up strength to start out, and the Internet services such as long-distance education, video conference, video request program, ecommerce flourish makes data traffic be explosive increase.The business demand of explosive increase has proposed Secretary to capacity, function and the performance of communication system.

The straightforward procedure that increases the communication system bandwidth is to lay more optical fiber, costs dearly but lay optical fiber, and is subjected to the restriction of the physical conditions such as natural environment, poor expandability.Another method is to adopt time division multiplexing (Time DivisionMultiplexing, TDM) technology, and it has improved transmission bit rate, but that the transmission capacity of simple optical fiber is still is limited, can not effectively utilize fiber bandwidth.Under this background, wavelength division multiplexing (Wavelength Division Multiplexing, WDM) technology is arisen at the historic moment.Wavelength division multiplexing is a kind of technology of transmitting a plurality of different wave length optical carriers in same optical fiber.The different wave length carrier signal is merged together by multiplexer (Multiplexer) at transmitting terminal, be put in an optical fiber and transmit; The different wave length carrier signal is separated by demodulation multiplexer at receiving terminal, be converted to original signal via optical receiver.In optical fiber, each wavelength independently transmits, and is independent of each other, and has improved greatly the transmission capacity of optical fiber, makes wavelength division multiplexing become best network capacity extension mode.Along with the reduction of optical device cost, and breakthrough and the maturation of the new technologies such as the modulation techniques such as DQPSK, DP-QPSK, electronic dispersion compensation, super out-of-band FEC coding, single wavelength 40Gbit/s, the systems such as transmission-link capacity 1.6Tbit/s are commercial.Japan NEC and French Alcatel realized on 100km distance respectively total amount be 10.9Tbit/s (273 * 40Gbit/s) with total amount be 10.2Tbit/s (the up-to-date world record of 256 * 40Gbit/s) transmission capacity.

Traditional point-to-point wdm system structure adopts simple linear mode, with the dilatation of wavelength path mode, a large amount of original bandwidth can be provided, it need to introduce at the network node place jumbo flexible optical node device just can be converted into the bandwidth that actual networking can flexible Application, realize that the WDM layer is interconnected, construct optical transfer network (Optical Transport Network, OTN).This class optical node device mainly comprises reconfigurable light bifurcated multiplexer (Optical Add-Drop Multiplexer, OADM) and optical cross connect (Optical Cross Connect, OXC).By at nodes place's introducing OADM, can insert or descend in this locality the wavelength of road one group selection, flexibly the up and down traffic carrying capacity.Along with the future development of WDM network towards mesh network, need to realize more coarsegrain at network hub node place, comprise wavelength, wavestrip, so that the processing light signal on the optical fiber granularity, OXC necessitates in hub node place's introducing.It is mainly completed in wavelength, wavestrip and the functions such as other connection of optical fiber level, bifurcated, protection and recovery.

Press application type, OXC can be divided into optical fiber interconnection (Fiber Cross Connect, FXC), wavelength is selected interconnection (Wavelength Selective Cross Connect, WSXC) and wavelength exchange interconnection (WavelengthInterchange Cross Connect, WIXC).FXC exchanges on any output optical fibre all wavelengths on an input optical fibre is disposable; WSXC exchanges to a wavelength on an input optical fibre on Same Wavelength on any output optical fibre; WIXC has wavelength conversion capability, a wavelength on an input optical fibre can be exchanged on any one wavelength on any output optical fibre.By implementation, OXC can be divided into the OXC (OEO-OXC, electric OXC) that adopts electric cross matrix and the OXC that adopts full optical cross-matrix (OOO-OXC, full light OXC).Electricity OXC is converted to the signal of telecommunication by opto-electronic conversion with light signal, after carrying out the interconnection processing, then is converted to light signal output.Full light OXC does not need to carry out opto-electronic conversion, and all intersections are all carried out at the WDM layer.OADM and OXC only select the wavelength up and down road of local service, and other wavelength are expedite by network node, are referred to as bypass.OADM and OXC have reconfigurability flexibly, make network have the wavelength routing capabilities, set up end to end the wavelength path (light path, lightpath).Along with the continuous progress of OADM and OXC technology, the WDM optical-fiber network develops towards complete mesh network from linear, ring network gradually.

Although OXC has networking capability flexibly, traditional OXC only has the static configuration ability.In recent years, IP operation becomes the main business amount of network service gradually, uncertainty and Unpredictability due to IP operation, dynamic-configuration to the network bandwidth requires more and more urgent, network need to have the ability of dynamic-configuration, and traditional mode time and effort consuming by human configuration is easily made mistakes, and can not in time configure, its shortcoming manifests gradually.The WDM optical-fiber network will adapt to the demand of new business; huge bandwidth capacity must can be taken full advantage of; rational distribution service; connect for business as soon as possible; and provide protection and Restoration Mechanism; the service of different service quality (Quality of Service, QoS) grade can also be provided according to the demand of business simultaneously.ASON (Automatic Switched Optical Network, ASON) ^[5,6]Produce under such background.It is the connection of managing network automatically, and this optical-fiber network with independent control plane is called ASON.

ASON can be found the variation of topology, resource and business automatically; Can set up the light connection with being connected fast, realize the dynamic assignment of Internet resources; Introduced the mechanism of protection and restoration of basic mesh network, can adopting more flexibly, mode provides protection and recovers for business; How novel high speed can be provided and increase income business, for example, super band width service and nonstandard bandwidth business, bandwidth on-demand business, the configuration of dynamic virtual ring and end to end circuit configuration service, virtual optical network business etc.At present, the positive formulation work of carrying out ASON domain-specific standard of the International Standards Organization such as International Telecommunications Union (ITU-T), internet engineering task group (IETF), OIF Optical Internetworking Forum (OIF) and light territory services interconnection alliance (ODSI).

1.2 network model

Along with business developments such as video conferences, the diversification gradually of Internet business, IP operation becomes main data traffic.The WDM optical-fiber network provides huge transmission capacity as leading transport network.The fusion of IP and WDM becomes the trend of future network development.The interconnect model of transmission network is also developed to IP over WDM double-layer structure by traditional IP over ATM over SDH/SONET over WDM multiple-layer overlapped structure gradually, as shown in Figure 1.In the network configuration of multiple-layer overlapped; the IP layer is used to provide business, and the ATM layer guarantees for service connection provides service quality (Quality of Service, QoS); the SDH/SONET layer utilizes its guard ring mechanism to provide protection and Restoration Mechanism for network, and the WDM layer provides huge transmission bandwidth.But in the multiple-layer overlapped network configuration, the cell mechanism of ATM has been brought larger overhead, has reduced bandwidth for transmission efficient.Along with the WDM optical-fiber network is developed to mesh network by looped network, although the SDH/SONET protection mechanism is effective fast, its protection cost is higher, and the protection mechanism of SDH/SONET is no longer applicable.In order to reduce the network operation cost, improve the bandwidth resources utilance, ATM layer and SDH/SONET layer fade away, and transmission network finally develops into the two-tier network structure of IP over WDM, and namely IP operation is directly transmitted on the WDM optical-fiber network.

In IP over WDM network, there are three kinds to control model, be respectively overlay model, peer-to-peer model and extended model.

(1) overlay model

Overlay model claims again client/server model, is proposed by ITU-T.As shown in Figure 2, IP layer and WDM layer are separate in this model, and control plane is separately arranged, and move different Routing Protocols, the routing iinformation such as switching network topology not between Routing Protocol.IP layer and WDM layer are by user-network interface (User to Network Interface, UNI) link together, the WDM layer is made of subnet, and is interconnected by Network-Network interface (Network to Network Interface, NNI) between each subnet.This model can realize that effective subnet divides, and facilitates the control of each subnet and upgrading etc.The IP layer can only be seen the light path of setting up between edge device in the WDM layer, and in this model, the internal structure of WDM layer network is transparent to the IP layer.The IP layer to WDM layer proposition business transmission request, is responsible for the control of light path by UNI by the WDM layer, the intelligence of network is reflected in the WDM layer fully.This model has realized that to greatest extent the control of WDM layer and IP layer separates.The shortcoming of overlay model is the light path set up between WDM layer edge device, be reflected as the logical links of IP layer, and the LSA of these links can cause very large network overhead.

(2) peer-to-peer model

Peer-to-peer model is proposed by IETF.As shown in Figure 3, in this model, IP layer and WDM layer are reciprocity, return unified control plane management.IETF is with this control plane called after GMPLS (GeneralizedMulti-protocol Label Switching, GMPLS).In peer-to-peer model, ip router and OXC all are called as LSR (Label Switching Router, LSR), identical route and the signaling protocol of they operations, the routing iinformation such as exchanging chain line state to each other, the IP layer can be seen the internal structure of WDM layer, and the WDM layer is no longer transparent to the IP layer.In peer-to-peer model, because IP layer and WDM layer are reciprocity, need to exchange a large amount of Link States and signaling control information between each LSR, cause very large network overhead.The internal structure of WDM network is unfavorable for the stable of network no longer to user transparent, also is unfavorable for the division of subnet in the WDM network; IP layer and WDM layer recovery mechanism need unified the coordination, control complicated.

(3) extended model

In extended model, IP layer and WDM layer are separate, move independently Routing Protocol, but can exchange some reachability information by UNI between them.Be for example the OXC distributing IP address in the WDM network, then offer the IP layer by WDM layer Routing Protocol and use, realize automatic pathfinding etc.The key issue of this model is how at UNI place's exchange reachability information.

The present invention is mainly for peer-to-peer model.

1.3 IP over WDM network key technology

In IP over WDM network, the IP layer provides layer as business, and the WDM layer is as transport layer, and its key issue is how to realize the seamless link of IP layer and WDM layer, and the GMPLS that IETF proposes provides a good solution thinking.In addition; the low speed service bandwidth granularity that IP admits is generally less than single wavelength capacities; so how effectively with service convergence, then carry these low speed business with the WDM layer in IP over WDM, and be problem demanding prompt solution for business provides corresponding protection/Restoration Mechanism.In order to address the above problem, mainly proposed at present GMPLS, Traffic grooming, with the closely-related route of Traffic grooming and the key technologies such as Wavelength Assignment and network survivability.

1.3.1GMPLS technology

GMPLS is the product that multi protocol label exchange (MPLS) develops to the WDM layer, and it has realized the seamless fusion of IP layer and WDM optical-fiber network effectively.GMPLS has inherited nearly all excellent characteristic such as traffic engineering in MPLS, simultaneously mpls protocol is expanded.GMPLS is absorbed in control plane, supports the exchange of the multiple resources granularities such as packet switching, time-division switching, wavelength exchange and space switching (optical fiber exchange).GMPLS also replenishes and revises original signaling and routing protocols in MPLS, and has designed brand-new LMP Link Manager Protocol (Link Management protocol, LMP).

(1) general multiple protocols label

GMPLS has defined five kinds of interface types, is respectively: (a) packet switch capable (Packet Switch Capable, PSC): carry out packet switching, by the identification boundaries of packets, according to the information forwarding grouping of packet header.(b) second layer Fabric Interface (Layer2 Switch Capable, L2SC): carry out cell switching, the border of passing through by identification forwards cell according to the information of cell head.(c) time division multiplexing capable (Time Division Multiplexing Capable, TDMC): carry out business according to the TDM time slot and forward.(d) lambda switch capable (Lambda Switch Capable, LSC): according to optical wavelength or the optical band forwarding service of bearer service.(e) fiber switch capable (Fiber Switch Capable, FSC): the physical location according to optical fiber in physical space forwards.GMPLS has done expansion to the label in MPLS, makes it also can carry out mark to TDM time slot, wavelength, wavestrip, optical fiber etc.GMPLS unifies mark to IP exchanges data, TDM circuit switching and the exchange of WDM light.The packet switching label continues to adopt the label in MPLS, and circuit switching and light switch label have been re-started definition, comprises request label, universal tag, suggestion label, sets label etc.Wherein, the request label is used for the foundation of label switched path (LabelSwitching Path, LSP); After universal tag was used for setting up LSP, indication was along the service conditions of LSP transmission; When the suggestion label is used for configuration LSP, the time delay of avoiding reverse configuration to cause, Rapid Establishment light connects; Set label and be used for the scope that the restriction downstream node is selected label.

(2) common tags switching path

Support the exchange of different resource granularity due to GMPLS, when setting up LSP for fear of the waste of bandwidth resources, the LSP of inferior grade (PSC, L2SC, TDMC, LSC, FSC grade reduce successively) need to be nested in high-grade LSP, be called again the LSP classification.The LSP classification technique realizes by the GMPLS labeled slots, after allowing the identical inferior grade LSP of entrance to converge, transparent passes high-grade LSP, then distal portion from.Use the device interface types of every LSP starting and ending of LSP sizing specification identical.Same-interface refers to that the interface of certain grade can use the multiplexing a plurality of LSP of certain technology.In MPLS, set up the unidirectional LSP that bidirectional LSP must be set up two opposite directions, its setup delay is long, signaling consumption is large.GMPLS improves it, can set up bidirectional LSP.Require the LSP of both direction to have identical traffic engineering parameter when setting up bidirectional LSP, comprise resource requirement, protection/Restoration Mechanism etc.When GMPLS set up bidirectional LSP, the path of uplink and downlink adopted same signaling message, and two LSP set up simultaneously, effectively reduced the time delay that LSP sets up, and had reduced signaling consumption.

(3) link management

In optical-fiber network, between two adjacent OXC in the quantity of parallel optical fiber link and every optical fiber multiplexing number of wavelengths be huge, provide broadcast mechanism if be respectively it, can cause the amount of information of link maintenance and when broadcasting transmission very large, be unpractical for every optical fiber, each wavelength provide an IP address simultaneously.For this reason, GMPLS has adopted link bundling and has processed this problem without the mode of numbering link.If parallel link belongs to identical link group, these links can be bound so, consist of a bar bundle link.Shared risk link group (Shared Risk LinkGroup, the SRLG) numbering that identical link group refers to belong to identical, identical link type of coding, identical protection/recovery type.Greatly reduce like this size of LSD, reduced the signaling consumption that broadcasting brings.Refer to without the numbering link, adopt the mode of (router id, link number) two tuples to identify the address of link, replace using the mode of IP address designation with this.GMPLS has formulated LMP Link Manager Protocol, is responsible for the functions such as control channel management between two adjacent nodes, link summary, link verification, fault management, and wherein link verification and fault management are optional.

(4) route and signaling protocol

When GMPLS adopts the general multiple protocols label to set up LSP; need to consider the factor of bandwidth and protection/recovery capability; this requires node need to record link-state information; GMPLS expands to respectively RSVP-TE and CR-LDP with defined two the signaling protocol RSVP of MPLS traffic engineering and LDP for this reason, exchanges the parameter such as bandwidth, type, protection/Restoration Mechanism of LSP by signaling.Route Selection both can adopt the explicit routing method, also can adopt the method for multi-hop.In addition, GMPLS also will expand to respectively OSPF-TE and IS-IS-TE for Routing Protocol OSPF and the IS-IS that traffic engineering in the territory is controlled.The link management mechanism such as the binding of GMPLS link, LMP Link Manager Protocol have well reduced the expense that in route and signaling protocol, the maintenance link state information is brought.

1.3.2 route and Wavelength Assignment

Given one group of connection creates a light path and distributes the process of a wavelength to be called route and Wavelength Assignment (Route and Wavelength Assignment, RWA) for each connects.Connection request can be divided into two kinds: static connection request and dynamic connection request.For static traffic, the set of service connection request is given in advance, its target is to set up light path for these connection requests, and minimize Internet resources used in global scope, such as number of wavelengths, fiber count etc., be the number of wavelengths of given fixed number, for connection request as much as possible is set up light path.Static routing and assignment of wavelength are called as static light path and set up (Static Lightpath Establishment, SLE) problem.For dynamic service, when connection request arrives, for it sets up light path, after business is left away, cancel light path.Its target is to set up light path for the business that dynamically arrives, and reduces blocking rate as much as possible, or maximizes the quantity of setting up light path in the synchronization network.Dynamic routing and Wavelength Assignment are called as dynamic light path and set up (Dynamic Lightpath Establishment, DLE) problem.

At present route and assignment of wavelength are decomposed into Route Selection and Wavelength Assignment two sub-problems.Whether first find a best route (for example shortest path), then checking has available wavelength for distributing.If because the successional constraint of wavelength does not have wavelength can distribute to this route, calculate so again the route of suboptimum, continue to repeat said process, until find a route that satisfies the wavelength continuity constraint, otherwise block connection request.Before finding this route, method iteration possibly many times, for this problem, has proposed the concept of wavelength hierarchical diagram, route and Wavelength Assignment is converted to the problem of graph theory, solves simultaneously the problem of Route Selection and Wavelength Assignment.

The define grid topology is N (R, A, L, W), and wherein R is the set of lambda router node, and A is the set of access node, and L is nonoriented edge, and W is the wavelength available number in every physical link.Each access node is bundled on a lambda router and provides electro-optical conversion to support the electricity exchange.Each limit is comprised of two reverse one-way optical fibers, can carry on each optical fiber | W| wavelength channel.Definition wavelength layered graph model is G (V, E), and it is a directed graph.The process that obtains the wavelength hierarchical diagram according to physical topology N is as follows: in N, each node i ∈ R copies in G | and W| time, these nodes are designated respectively If link l ∈ L connection route device i and router j, i wherein, j ∈ R, so for any w ∈ W,

With

By a directed edge

Link together, wherein,

Suppose that access node a ∈ A is connected on lambda router node r ∈ R.In G, for each access node a creates two nodes, one represents business generating portion (source), and another one represents business teste (purpose).These two nodes are designated respectively Add in G

To node

And

Arrive

Directed edge.Therefore the number of node in G | V|=|R| * | W|+2 * | A|; The number of directed edge | E|=2 * | L| * | W|.For example, the wavelength hierarchical diagram that physical topology shown in Figure 4 is corresponding as shown in Figure 5.Wherein, the link between every lambda router is comprised of two reverse one-way optical fibers, and every optical fiber medium wave long number is 2.By the wavelength hierarchical diagram, route just becomes relative simple with assignment of wavelength.As long as found the route that connects source and destination on certain wavelength plane, this route satisfies the wavelength continuity constraint surely with regard to one.

1.3.3 Traffic grooming

The WDM optical-fiber network provides huge transmission capacity, and the system of single wavelength capacities 40Gbit/s is commercial.The bandwidth on demand of each business is compared relatively low with single wavelength capacities, for example OC-12, OC-48, OC-192 but in actual applications.Think that each low speed service request distributes a wavelength can cause a large amount of bandwidth waste.For each request creates a light path, also can increase the electric switching cost (for example needing to dispose more optical transceiver) of network, increase the cost of network.The most important thing is, the wavelength available number in real network than the low speed business number that arrives lack many.So Traffic grooming is the basic function that the WDM optical-fiber network must have, to increase network throughput, improve the wavelength resource utilance, reduce network cost.In the WDM optical-fiber network, Traffic grooming is exactly the technology of transmitting on low speed service convergence to a high speed light path, and its target is to minimize network cost or maximization network throughput.

In the WDM optical-fiber network, Traffic grooming need to solve the problem of three aspects:: (1) sets up light path, and (2) distribute wavelength to satisfy the wavelength continuity for light path, and (3) are route low speed business on logical topology.Whether given in advance according to business, Traffic grooming can be divided into two classes: the static traffic amount is dredged with the dynamic service amount and is dredged.Dredge for the static traffic amount, the method that these three problems can adopt shaping linear programming (Integer Linear Programming, ILP) to optimize solves together.But for catenet, the complexity of problem solving rises, and generally adopts heuritic approach to solve respectively three problems.In the dynamic service amount is dredged, when service connection request arrives, be on logical topology that at first it seeks route, if purpose is unreachable or existing light path on bandwidth be finished, create so new light path carrying new business and connect.

1.3.4 network survivability

After network survivability referred to break down, network can provide the ability of persistent service.Development along with WDM technology, can multiplexing hundreds and thousands of wavelength in single fiber, the capacity of each wavelength also reaches tens hundreds of Gbit/s even, in case network failure (as link failure etc.) occurs, the service failure that can cause the Tbit/s order of magnitude causes to have a strong impact on.Therefore the survivability of WDM optical-fiber network becomes the major issue of people's growing interest.

WDM layer Survivability technology can be divided into two classes: protection (Protection) and recovery (Restoration).Protection refers to reserve reserved resource for business in advance when business connects, in case break down, business turns by reserved resource carries.Protection has shorter protection switching time, but because needs are reserved reserved resource in advance, and when not breaking down, reserved resource is idle, so resource utilization is low.Recovery refers to not reserve reserved resource for business in advance, when fault occurs, then basis network resource usage situation at that time, the mode of employing heavy-route is sought the affected business of idling-resource carrying dynamically.Recovery has higher resource utilization, but owing to being to seek dynamically again the available resources bearer service after fault occurs, so protection is long switching time, and heavier when offered load, when there is no enough available resources, can cause the fault recovery failure.

Whether share according to reserved resource, protection mechanism is divided into again two classes: privacy protection (Dedicated Protection) and share protect (Shared Protection).In privacy protection, to monopolize for the reserved resource of certain work road reservation, other protects the road not re-use.In share protect, if two work Lu Buhui break down (being that physical link separates as two roads of working) simultaneously, they can the share protect resource so.From the angle of resource utilization, share protect is higher than privacy protection resource utilization, and the traffic intensity of network is higher, and the advantage of share protect is more obvious.The protection switching time aspect, privacy protection is shorter than share protect.This is because in privacy protection, reserved resource is monopolized, can be pre-configured, in case break down, just influenced business is switched in reserved resource; And in share protect, can not prejudge which service failure, and can not configure in advance, only have after fault occurs, then by the devices such as OXC on certain signaling mechanism configuration protection road, so its protection is longer switching time.

According to the granularity of protection, protection mechanism can be divided into path protection, link protection and sectionalised protection again.Path protection refers to provide one to protect end to end the road for the road of working.Link protection refers to be one of work each link calculation on road protection road, in case break down, the switching of business is responsible at faulty link two ends, need not the sourcesink node and participates in.In sectionalised protection, the road segmentation of first working, then be that the road is protected in each one of section calculating, a first section tail of section is responsible for fault recovery.Comparatively speaking, path protection has higher resource utilization, and the fault recovery of link protection need not the sourcesink node and participates in, and has that to protect faster switching time, sectionalised protection be to attempt seeking balances between both.

A kind of as in Survivability technology, resist technology has protects switching time faster, can satisfy the requirement of a large amount of real time business, so the present invention relates generally to resist technology.

2 network models

2.1 network node

Network node is comprised of the OXC that combines and ip router.Wherein, ip router is responsible for the admission service request.OXC forms (as shown in Figure 7) by wavelength switching matrix, low speed traffic grooming matrix and one group of tunable transceiver.Wavelength in input optical fibre can directly exchange to the corresponding wavelength of output optical fibre by the wavelength switching matrix and get on after demultiplexing, perhaps exchanges to optical receiving set and is transformed into the signal of telecommunication and enters low speed and dredge matrix.Belong to local business and transfer to the ip router processing by the low-speed service data flow port, non-local business is converted to light signal by optical transmitter, reenters the wavelength switching matrix, and the respective wavelength that exchanges to corresponding optical fiber gets on.That is to say, do not contain local service in certain wavelength channel in input optical fibre and can directly pass through the wavelength switching matrix to output optical fibre, namely bypass; Has the wavelength channel of business up/down by processing under optical transceiver in electric territory.Each network node has been safeguarded overall link-state information, comprises the operating position of wavelength on each physical link, operating position of bandwidth etc. on each light path.

In addition, the constraints of the present invention's consideration mainly contains: the wavelength continuity constraint under the constraint of optical transceiver number, the conversion of sparse part wavelength, sparse part light splitting constraint etc.

(1) optical transceiver number

(2) wavelength conversion capability

Refer to without the wavelength transfer capability, the wavelength channel in input optical fibre can only exchange to by the wavelength switching matrix that in output optical fibre, the wavelength channel of identical wavelength gets on.

Wavelength conversion capability refers to fully, and the wavelength channel in input optical fibre gets on by the wavelength channel that the wavelength switching matrix can exchange to any wavelength in output optical fibre.

The part wavelength conversion capability, the wavelength channel in input optical fibre gets on by the wavelength channel that the wavelength switching matrix can exchange to wavelength in certain limit adjacent with this wavelength in output optical fibre.For example, certain node has the part wavelength conversion capability, and its wavelength conversion range is 2, so wavelength X ₄Can transform to wavelength X ₂, λ ₃, λ ₅And λ ₆Get on.Wavelength conversion range with node of part wavelength conversion capability may be not identical yet.

(3) light splitting ability

In the WDM optical-fiber network, if will make node have multicast capability, need to be at the node deployment optical splitter.According to the power of light splitting ability, network node can be divided three classes: without light splitting ability MI (Multicast Incapable), complete light splitting ability, part light splitting ability.

Refer to without the light splitting ability, node can only be sent an input signal into an output port, if it is not the multicast destination node, and so can only be as the non-bifurcation node in the centre of multicast tree; If it is the multicast destination node, it can only be as the leaf node of multicast tree so.

The light splitting ability refers to fully, and node can be sent into input signal any a plurality of output port.

Part light splitting ability refers to, node can be sent into input signal the output port of some.

Rear two kinds of nodes are referred to as MC (Multicast Capable) node, both can be used as the destination node of multicast tree, also can be used as the intermediate node of light tree.When as middle node of divergence, for the node of complete light splitting ability, its out-degree is restriction not; For the node of part light splitting ability, if it is not destination node, but its out-degree can not surpass its maximum light splitting number so; If simultaneously as destination node, need to tell one road light signal on this underground road, but can not surpassing its maximum light splitting number, its out-degree subtracts one.

The co-wavelength transfer capability is the same, for convenience, counts the light splitting ability of description node but the present invention is unified with the maximum light splitting, but the maximum light splitting number that does not have the node of light splitting ability is made as 1, and the node wave length conversion range with complete light splitting is degree of node.

Existing wavelength conversion capability has again the node of light splitting ability that two kinds of node structures are arranged: (1) first carries out wavelength conversion, after carry out light splitting, (2) first carry out light splitting, after carry out the wavelength conversion.The first node structure is simpler, and its two wavelength telling must have identical wavelength, have certain limitation.The second node structure is more flexible, is the direction of development in the future, and its each light splitting wavelength out can carry out the wavelength conversion, and is therefore many to the quantitative requirement of wavelength shifter.In addition, from the angle of method, design is special circumstances (transforming to after light splitting on identical wavelength) of the second node structure based on the method for the first node structure in fact, so the present invention adopts the second node structure.

2.2 network link

Connected by the opposite one-way optical fiber of a pair of transmission direction between two network nodes.Article two, optical fiber has identical wavelength set, and number of wavelengths is | W|.Article two, optical fiber is that physical link separates, and in the use of wavelength, and separate in the transmission of data, be independent of each other.

2.3 basic structure

For given physical topology G _p(V, L, W) is according to following steps structure multilayer auxiliary view.

(1) with each node v _i∈ V, i=1,2 ..., | V|, copy | W| time, be labeled as respectively Be called the wavelength node.Have identical ID by the duplicated all wavelengths node of same node, be its physical node ID.If from node v _iTo node v _jAn oriented physical link l is arranged _ij, so for all w=1,2 ... | W|, from the wavelength node

To the wavelength node

Increase a link

Be called wavelength span, every wavelength span is corresponding to wavelength in its place physical link.So just, constructed the wavelength hierarchical diagram, the topology that the wavelength node that wherein each wavelength is corresponding and wavelength span consist of is called the wavelength plane.For example, (suppose that every physical link medium wave long number is 2) as shown in Figure 8 according to the wavelength hierarchical diagram of physical topology structure in Fig. 6.

(2) with each node v _i∈ V, i=1,2 ..., | V| copies one time, is designated v ' _i, be called logical node.Logical node is used for receiving and is connected with winding-up, can be understood as the ip router node.If at the WDM layer, there is one from node v _iTo node v _jLight path, increase so one from node v ' _iTo node v ' _jVirtual link, be called logical links (logical links is light path hereinafter), the bandwidth of logical links is the capacity (supposing that all light paths are all single wavelength channels) of a wavelength.The topology that is made of logical node and logical links is called logical topology.Logical topology and wavelength hierarchical diagram are combined just consisted of basic multilayer auxiliary view.Or take the topology of Fig. 6 as example, suppose with wavelength X ₂Created one from node v ₂To node v ₄Light path, light path is through intermediate node v ₃On the wavelength hierarchical diagram Arrive

And

Arrive

Wavelength span be labeled as and use, on logical topology, increase v ' ₂To v ' ₄Logical links, the multilayer auxiliary view that obtains is as shown in Figure 9.

2.4 optical transceiver number constraint

When business is carried out Traffic grooming, sometimes utilize existing logical links to can not find the route that can reach destination node, at this moment need newly-built light path.During each newly-built light path, the light path source node need to consume an optical transmitter, and destination node consumes an optical receiver.Logical links need to record available light transmitter number and available light receiver number as the admittance node of business.As long as source, destination node have one not meet the demands, light path just can not be set up.For the digitlization constraint with the optical transceiver number, be converted into the content of graph theory, adopt the conceptual description optical transceiver number constraint of admitting link.For arbitrary node v _i∈ V, i=1,2 ..., | V| increases v ' _iArrive

And

To v ' _iThe admittance link.

Take Fig. 9 as example, suppose that each Nodes optical receiver number and optical transmitter number average are 2, due to v ₂To v ₄So newly-built light path is v ₂Place's available light transmitter number subtracts one, v ₄Place's available light receiver number subtracts one.The multilayer auxiliary view that obtains so as shown in figure 10, the other numeral of logical node wherein, the expression available light transmitter number of front, the expression available light receiver number of back.

2.5 wavelength conversion capability constraint

The present invention considers sparse part wavelength conversion capability constraint, and this constraint can solve by improving the multilayer auxiliary view.

For arbitrary node v _i∈ V, its wavelength conversion range is r, increases so

W1=1,2 ..., | W| arrives

W2=max{1, w1-r} ... w1-1, w1+1 ... min{|W|, the virtual link of w1+r} is called the wavelength transfer link.

After introducing wavelength conversion capability, the structure of light path and light tree changes to some extent.

(1) light path

Light path in general sense requires each wavelength span of light path process to have identical wavelength in order to satisfy the wavelength continuity constraint, and namely light path is comprised of one group of wavelength span with identical wavelength.Only need to find the route of linked source, destination node to get final product on certain wavelength plane when a newly-built light path.After considering wavelength conversion capability, each wavelength span of light path process can use different wavelength, when a newly-built light path, is no longer just route on certain wavelength plane, but on the multilayer auxiliary view route.The ordered set that this moment, light path was comprised of wavelength span and wavelength transfer link.

(2) light tree

After introducing wavelength conversion, each node on the light tree is the wavelength node, and father node may be wavelength span or wavelength transfer link to the link of child nodes.

3 based on the dedicated multi-layered guard method of the clean culture of load balancing

3.1 link cost

The present invention adopts the working load of bandwidth on the balanced and light path of wavelength working load on physical link balanced, affected number of services when as far as possible reducing generation physical link fault.

In order better to realize load balancing, the present invention is that wavelength transfer link, logical links, admittance link, wavelength span are provided with different grades, is called α _wcl, α _ll, α _al, α _wllWavelength transfer link priority is the highest, is thereafter logical links, admittance link, wavelength span successively.Having a long way to go of the grade factor, for example be respectively 1,100,10000,1000000, its objective is weights for each node that can obtain according to the Dijkstra shortest path algorithm analyze through wavelength conversion chains link way, logic chain way, admit number of links and wavelength span number.Secondly number of links less path is selected to admit, even with the less path of optical transceiver number, to reduce the quantity of newly-built light path number, the last operating position of Compare Logic link again in the minimum path of preferential choice for use wavelength span when this just impels routing.

Admit the grade factor of link and wavelength span can reach different optimization aim by change.In upper example, main target is for using minimum number of wavelengths.If will admit the larger grade factor of link setting, its optimization aim just becomes the minimum optical transceiver number of use so, and this mainly is applicable to the network that the optical transceiver number is major constraints.

3.1.1 wavelength transfer link

, the load of network are not exerted an influence, so the link cost of wavelength transfer link is suc as formula shown in 3.1 except the time-delay that the conversion of introducing wavelength brings due to the wavelength transfer link.

W _wcl＝1×α _wcl (3.1)

Due on the multilayer auxiliary view, when using the method processing node wavelength conversion capability of 2.5 joint introductions, there is the problem of continuous wavelength conversion.For example, if the excursion of certain node is 2, wavelength X so ₅Can transform to wavelength X ₇But, wavelength X ₇Can transform to λ ₉, by twice wavelength conversion, wavelength X ₅Transformed to wavelength X ₉But the wavelength variation range that the fact is this node is 2, wavelength X ₅Can not transform to λ ₉In the present invention, when operation dijkstra's algorithm pathfinding on the multilayer auxiliary view, when certain wavelength node of expansion, if its previous dive node is the wavelength node, and with it, identical node ID is arranged, be that its previous dive link is the wavelength transfer link, so in expansion during this node, the link cost of the wavelength transfer link in its neighbours limit is by ∞ calculating (the physical link cost of this wavelength transfer link be still 0 constant).Cause the wavelength conversion to exceed the problem of wavelength conversion range with regard to having avoided by continuous double bounce wavelength transfer link like this.In the path that calculates like this, at each Nodes, a wavelength transfer link can only be arranged at most before and after it.The dijkstra's algorithm of hereinafter using is all as above processed.

3.1.2 logical links

Each logical links is corresponding a light path of WDM layer all, and the capacity of logical links bandwidth is exactly the bandwidth capacity of light path.Article one, the loading condition of logical links can have multiple balancing method, such as the quantity of the LSP that carries on this logical links, dedicated bandwidth accounts for the ratio of total bandwidth etc.Consider the bandwidth difference that different business is asked, simply be difficult to the loading condition of reflected optical path with the business number, dedicated bandwidth accounts for the ratio of total bandwidth as the standard of weighing a logical links loading condition so select.To account for the ratio of total bandwidth higher for dedicated bandwidth, and the load of this logical links is heavier, will avoid as much as possible this link when routing, so will be the larger link cost of this link setting.In like manner, account for the lower less link cost of link setting of ratio of total bandwidth for dedicated bandwidth.

Make b _t, b _w, b _p, b _rRepresent respectively total bandwidth, bandwidth of operation, protection bandwidth and user's bandwidth on demand of this logical links, the link cost of this logical links is suc as formula shown in 3.2 so.

W_{ll} = \{\begin{matrix} \infty & b_{t} - b_{w} - b_{p} < b_{r} \\ (1 + \frac{b_{w} + b_{p}}{b_{t}}) \times α_{n} & b_{t} - b_{w} - b_{p} &GreaterEqual; b_{r} \end{matrix} - - - (3.2)

3.1.3 admittance link

The link cost of admitting link is the operating position that reflects this Nodes optical transmitter and optical receiver.For certain node, during as the source node of new light path, consume optical transmitter of this Nodes when this node; During as destination node, consume an optical receiver when this node, so separate during the operating position of optical transmitter and optical receiver for certain node.

Make t _t, r _t, t _a, r _aRepresent respectively the total optical transmitter number of this Nodes, total optical receiver number, available light transmitter number and available light receiver number, the link cost from logical node corresponding to this node to the admittance link of the corresponding all wavelengths node of this node is suc as formula shown in 3.3 so.

W_{al} = \{\begin{matrix} \infty & t_{a} = t_{t} \\ (1 + \frac{t_{t} - t_{a}}{t_{t}}) \times α_{al} & t_{a} \leq t_{t} \end{matrix} - - - (3.3)

The corresponding all wavelengths node of this node to the link cost of the admittance link of its logical node suc as formula shown in 3.4.

W_{al} = \{\begin{matrix} \infty & r_{a} = r_{t} \\ (1 + \frac{r_{r} - r_{a}}{r_{t}}) \times α_{al} & r_{a} < r_{t} \end{matrix} - - - (3.4)

3.1.4 wavelength span

The link cost of wavelength span is the loading condition that reflects physical link under this wavelength span.The loading condition of physical link can be weighed with the ratio that accounts for total number of wavelengths with number of wavelengths.Wavelength span has four kinds of use states: do not use, be used to build light path, be used to build the light tree, be used to protection.

Make w _w, w _pOperating wave long number and protection number of wavelengths in physical link under this wavelength span respectively, if this wavelength span is used, its link cost is ∞ so, otherwise its link cost is suc as formula shown in 3.5.

W_{wll} = \{\begin{matrix} \infty & w_{w} + w_{p} = | W | \\ (1 + \frac{w_{w} + w_{p}}{| W |}) \times α_{wll} & w_{w} + w_{p} < | W | \end{matrix} - - - (3.5)

Two, the dedicated multi-layered guard method of the clean culture based on load balancing in optical-fiber network of the present invention, comprise the steps:

Step (1), set up working LSP for service request, concrete steps are as follows:

Step (1.1), link cost is set

The link cost of each wavelength transfer link, logical links, admittance link and wavelength span is set according to formula 3.1～3.5;

Step (1.2), pathfinding

Step (1.2.1), utilize dijkstra's algorithm to calculate one from v ' _sTo v ' _dShortest path judge whether pathfinding success;

Step (1.2.2) is if service request is refused in failure, and method finishes;

Step (1.3), format LSP

For each link in LSP:

Step (1.3.2) does not process if be logical links;

Through format, LSP has become a set that only is made of logical links;

Step (1.4), Resources allocation

Step (2), be that service request sets up protection LSP

For protection LSP and working LSP can not broken down simultaneously, it is that physical link separates with working LSP that protection LSP requires, and the establishment step of protection LSP is as follows:

Step (2.1), link cost is set

It is ∞ that the corresponding all wavelengths link of physical link of working LSP process and the link cost of logical links are set; The link cost of all the other each wavelength transfer links, logical links, admittance link and wavelength span is set according to formula 3.1～3.5;

Step (2.2), pathfinding

Step (2.2.3) is if success continues execution in step (2.3);

Step (2.3), format LSP

For each link in LSP:

Step (2.3.2) does not process if be logical links;

Through format, LSP has become a set that only is made of logical links;

Step (2.4), Resources allocation

Step (3), the operating load light path of attaching most importance to provide the protection of WDM layer

The operating load of light path is different from the load of light path, and operating load refers to that bandwidth of operation accounts for the ratio of light path total bandwidth.The threshold value that has surpassed appointment when the operating load of light path

The time, be called heavy industry and make the load light path, provide the protection of WDM layer at the WDM layer for it.The present invention adopts path protection, and the light path of the operating load of attaching most importance to provides the protection of WDM layer.Along with leaving away of business, provided originally that the load of the working light path of WDM layer protection may become lower than threshold value

Protect the road if delete its protection this moment, may have again so a new business to use this light path to make its load surpass threshold value at once

This just can introduce jitter problem.So the present invention arranges another threshold value

When working light path its load that the protection of WDM layer is provided lower than threshold value The time just delete its protection road;

When set up working LSP and protection LSP for service request after, check successively working LSP each logical links (every logical links all corresponding a light path) of process, if its load has surpassed the threshold value of appointment And the protection of WDM layer is not provided, and for this light path creates a protection light path, the protection light path need to be separated with its physical link so.The source node that makes this heavy industry make the load light path is v _a, destination node is v _b, concrete steps are as follows:

Step (3.1), link cost is set

The link cost that heavy industry is made the corresponding all wavelengths link of physical link of load light path process is set to ∞; The link cost of all logical links is set to ∞; The link cost of all the other wavelength spans is set according to formula 3.5; According to formula 3.3, v ' is set _aAll go out edge joint and receive the link cost of link; According to formula 3.4, v ' is set _bAll enter edge joint and receive the link cost of link; All the other admit the link cost of link to be set to ∞;

Step (3.2), pathfinding

Step (3.3), Resources allocation

Protection light path source node place available light transmitter number subtracts one; Light path destination node place available light receiver number subtracts one; Each wavelength span use state of protection road process is set to " being used to protection ";

Because the protection light path can not be used for bearer service, so it is not mapped on logical links.

Step (4), releasing resource when business is left away

When business is left away, need to discharge the resource that takies on its working LSP and protection LSP, concrete steps are as follows:

Step (4.2), for WDM layer protection is provided but operating load lower than

Wherein: A threshold value for the operating load appointment of light path;

In optical-fiber network of the present invention based on the overview flow chart of the dedicated multi-layered guard method of clean culture of load balancing as shown in figure 11.

Claims

1. the dedicated multi-layered guard method of the clean culture based on load balancing in an optical-fiber network, is characterized in that: comprise the steps:

Step (1), set up working LSP (label switched path) for service request, concrete steps are as follows:

Step (1.1), link cost is set

Wherein: α _wclThe grade factor for the wavelength transfer link;

According to formula

W_{ll} = \{\begin{matrix} \infty & b_{t} - b_{w} - b_{p} < b_{r} \\ (1 + \frac{b_{w} + b_{p}}{b_{t}}) \times α_{ll} & b_{t} - b_{w} - b_{p} &GreaterEqual; b_{r} \end{matrix}

The link cost W of each logical links is set _ll

According to formula

W_{al} = \{\begin{matrix} \infty & t_{a} = t_{t} \\ (1 + \frac{t_{t} - t_{a}}{t_{t}}) \times α_{al} & t_{a} < t_{t} \end{matrix}

According to formula

W_{al 1} = \{\begin{matrix} \infty & r_{a} = r_{t} \\ (1 + \frac{r_{t} - r_{a}}{r_{t}}) \times α_{al} & r_{a} < r_{t} \end{matrix}

The corresponding all wavelengths node of each node is set to the link cost W of the admittance link of its logical node _al1

α _alFor admitting the grade factor of link;

According to formula

W_{wll} = \{\begin{matrix} \infty & w_{w} + w_{p} = | W | \\ (1 + \frac{w_{w} + w_{p}}{| W |}) \times α_{wll} & w_{w} + w_{p} < | W | \end{matrix}

The link cost W of each wavelength span is set _wll

α _wllThe grade factor for wavelength span;

| W| is the number of wavelengths in every physical link;

Step (1.2), pathfinding

Wherein: v ' _sBe v _sLogical node, v _sBe source node;

v′ _dBe v _dLogical node, v _dBe destination node;

Step (1.2.2) finishes based on the dedicated multi-layered guard method of the clean culture of load balancing if service request is refused in failure;

Step (1.3), format LSP

For each link in LSP:

Step (1.3.2) does not process if be logical links;

Through format, LSP has become a set that only is made of logical links;

Step (1.4), Resources allocation

Step (1.4.2), upgrade successively the bandwidth usage of each logical links on the LSP path;

Step (2.1), link cost is set

Wherein: α _wclThe grade factor for the wavelength transfer link;

According to formula

W_{ll} = \{\begin{matrix} \infty & b_{t} - b_{w} - b_{p} < b_{r} \\ (1 + \frac{b_{w} + b_{p}}{b_{t}}) \times α_{ll} & b_{t} - b_{w} - b_{p} &GreaterEqual; b_{r} \end{matrix}

The link cost W of each logical links is set _ll

According to formula

W_{al} = \{\begin{matrix} \infty & t_{a} = t_{t} \\ (1 + \frac{t_{t} - t_{a}}{t_{t}}) \times α_{al} & t_{a} < t_{t} \end{matrix}

According to formula

W_{al 1} = \{\begin{matrix} \infty & r_{a} = r_{t} \\ (1 + \frac{r_{t} - r_{a}}{r_{t}}) \times α_{al} & r_{a} < r_{t} \end{matrix}

α _alFor admitting the grade factor of link;

According to formula

W_{wll} = \{\begin{matrix} \infty & w_{w} + w_{p} = | W | \\ (1 + \frac{w_{w} + w_{p}}{| W |}) \times α_{wll} & w_{w} + w_{p} < | W | \end{matrix}

The link cost W of each wavelength span is set _wll

α _wllThe grade factor for wavelength span;

| W| is the number of wavelengths in every physical link;

Step (2.2), pathfinding

Step (2.2.2) is if failure discharges the resource that working LSP takies, and the refusal service request finishes based on the dedicated multi-layered guard method of the clean culture of load balancing;

Step (2.2.3) is if success continues execution in step (2.3);

Step (2.3), format LSP

For each link in LSP:

Step (2.3.2) does not process if be logical links;

Through format, LSP has become a set that only is made of logical links;

Step (2.4), Resources allocation

Step (2.4.2), upgrade successively the bandwidth usage of each logical links on the LSP path;

When set up working LSP and protection LSP for service request after, check successively working LSP each logical links of process, every logical links here is corresponding light path all, if its load has surpassed the threshold value of appointment

Be called heavy industry and make the load light path, need to provide the protection of WDM layer for it at the WDM layer; If this heavy industry is made the load light path and is not provided the protection of WDM layer, for this light path creates a protection light path, the protection light path need to be separated with its physical link so; The source node that makes this heavy industry make the load light path is v _a, destination node is v _b, concrete steps are as follows:

Step (3.1), link cost is set

The link cost of all logical links is set to ∞;

According to formula

W_{wll} = \{\begin{matrix} \infty & w_{w} + w_{p} = | W | \\ (1 + \frac{w_{w} + w_{p}}{| W |}) \times α_{wll} & w_{w} + w_{p} < | W | \end{matrix}

The link cost of all the other wavelength spans is set;

According to formula

W_{al} = \{\begin{matrix} \infty & t_{a} = t_{t} \\ (1 + \frac{t_{t} - t_{a}}{t_{t}}) \times α_{al} & t_{a} < t_{t} \end{matrix}

V ' is set _aAll go out edge joint and receive the link cost of link;

According to formula

W_{al 1} = \{\begin{matrix} \infty & r_{a} = r_{t} \\ (1 + \frac{r_{t} - r_{a}}{r_{t}}) \times α_{al} & r_{a} < r_{t} \end{matrix}

V ' is set _bAll enter edge joint and receive the link cost of link;

All the other admit the link cost of link to be set to ∞;

Wherein: v ' _aThe source node v of the operating load light path of attaching most importance to _aLogical node;

v′ _bThe destination node v of the operating load light path of attaching most importance to _bLogical node;

Step (3.2), pathfinding

Step (3.2.2) is if failed, and the WDM layer is protected unsuccessfully, finishes based on the dedicated multi-layered guard method of the clean culture of load balancing;

Step (3.3), Resources allocation

Step (4.2), for WDM layer protection is provided but operating load lower than

Wherein:

Be a threshold value of the operating load appointment of light path,