CN100421397C - Optical burst switched network performance and fault monitoring method - Google Patents

Abstract

The present invention discloses a method for monitoring the performance and the faults of an optical burst switching network, which relates to the technical field of optical communication. The method generates detecting burst PB and corresponding detecting burst control packets PBHP in data channels of an optical burst switching network; through detecting bursts, faults in an optical layer are reflected to an electric layer to monitor the performance index of the network. Under the control of a control plane and a management plane, PB is transmitted on the data channels which need to be detected periodically, and PBHP corresponding to PB is transmitted in advance on control channels; PB is received and taken out on a next hop network node which transmits the PB node, and bits in PB are verified to count and analyze the error code condition of the bits; if a fault warning threshold is exceeded, net elements send out warning messages. The present invention can quickly reflect the faults in the optical layer to the electric layer through the detecting bursts, can switch or restore quick protection needed by network survivability and can position faults to provide quick exact fault information.

Description

A kind of optical burst switched network performance and fault monitoring method

Technical field

The present invention relates to communication technical field, relate in particular to the malfunction monitoring of optical interconnection network.

Background technology

OBS combines the technological merit of optical circuit exchange and light packet switching, is one of preferred version of full optical internet of future generation.Light burst exchange network can be regarded as the superimposed network of data transport network of electric territory Control Network and full light, it uses signal of telecommunication control optical cross connect (OXC) equipment, finish the quick interconnection of wavelength channel, be considered to very promising wavelength division multiplexing (WDM) network exchange form.Improve the monitoring mechanism in light territory, make the monitoring parameter in light territory can guarantee that the operate as normal of this layer is a popular research direction always.As document: Wen, Y.; Chan, V.W.S.; EfficientFault-Diagnosis Algorithms for All-Optical WDM Networks WithProbabilistic Link Failures, Zheng, L.Lightwave Technology, IEEEJournal of Volume 23, Issue 10, discloses among the Oct.2005, but because current light logic function is very limited, the prematurity still of light caching technology, improving of light territory monitoring parameter also will be a long-term process.Before the monitoring mechanism maturation in light territory, the light territory must be monitored by the survivabilities such as error code supervision, connected state, remote bug indication that the electric territory business of being carried is finished oneself, as, when the SDH system finished these functions, ATM and transmits on WDM in the SDH over wdm system, ATM finished this function etc.In these systems, it is that light signal is converted into the signal of telecommunication and carries out the bit verification that light signal all will carry out single-hop test (single-hop test) at each node, signal regeneration etc., and then through the electric light conversion, send, the fault in light territory can be monitored in a jumping scope.But, because the light burst exchange network data channel transmission is transparent full light signal.And electric territory business can not guarantee the quality of institute's carrying signal.Utilize the electricity layer that signal is carried out the way that verification comes monitor channel performance, in full optical transparency network, be difficult to again realize.Thereby existing above-mentioned monitoring method and be not suitable for light burst exchange network.

Summary of the invention

Technical problem to be solved by this invention is: at data channel transmission in the light burst exchange network is transparent full light signal, the present situation that does not have perfect fault detect means in the prior art, the present invention proposes a kind of new light burst exchange network data channel performance monitoring mechanism, this mechanism periodically or with certain ad hoc fashion sends the detection burst at light burst exchange network network element node to data channel, and survey the error condition of burst in the monitoring of each core node hop-by-hop, assess per two internodal data channel states, judge the soft or hard fault of monitored network with this.

The technical solution adopted for the present invention to solve the technical problems is: utilize light burst exchange network data channel idle period or take under the situation of low volume data channel resource, burst PB (Probe Burst) and the corresponding control grouping bag PBHP (Probe BurstHeader Packet) that surveys burst are surveyed in artificial generation, by surveying burst, the fault of photosphere can be reflected to the electricity layer rapidly, thus the performance index of on-line monitoring network.The present invention can further monitor soft, the hard fault of light burst exchange network, and fault monitoring method specifically comprises the steps: to produce the control grouping PBHP (Probe Burst Header Packet) that surveys burst PB (Probe Burst) and corresponding detection burst at each network element node of light burst exchange network; Under control plane or management plane control, periodically (or with other prescribed manner) sends the PB with fixed bit pattern explore frame on the data channel that desire is surveyed, and sends its corresponding control grouping PBHP in advance on control channel; Take out PB at the next-hop network node that sends the PB node, and the bit among the PB is carried out verification, its error condition of statistical analysis deposits the error situation statistical log in; If error code extremely worsens, exceed the hard fault alarming threshold, network element is just sent hard fault and is alarmed to protection recovery module; Error condition and error code history are compared analysis, if error condition exceeds the soft fault alarming threshold, network element is just sent soft fault and is alarmed to network management center so.

The invention has the beneficial effects as follows that do not need the complicated outer monitoring equipment of joining, it can provide warning information fast and accurately for needed quick protective switch of network survivability or recovery; It can also be management maintenance purpose fault location, and accurately detailed soft or hard fault message is provided, and it is applicable to any network size, any network topology and control mode, and autgmentability is good.

Description of drawings

Fig. 1 data burst DB, detection burst PB signal format example

Function diagram (b) the fringe node exit portion function diagram of Fig. 2 (a) fringe node intake section

The core node functional structure chart of Fig. 3 band detecting module

Fig. 4 PB and the DB transmission schematic diagram in OBS

Fig. 5 fault monitoring principle flow chart

Embodiment

Hard fault in the optical-fiber network is caused by disconnected fibre, power down, laser or receiver damage, artificial attack etc. that often it can cause communication interruption, causes a large amount of burst loss in the short time, a large amount of sudden error codes.Soft fault is often by device aging, and temperature drift etc. cause, show as the rising of unit interval random error number (random error rate).The state of channel can estimate by the sampling to channel, in data channel, periodically or with certain ad hoc fashion, send and survey burst, be equivalent to the state of data channel has been carried out sample investigation,, come the state of assessment data channel to survey the error condition of burst.If survey the explore frame of encapsulation in the burst, fixing bit pattern is arranged, receiving terminal only needs the explore frame that encapsulates among the PB is compared with standard pattern after receiving PB so, just the mistake among the PB is a random error as can be known, or unexpected error.As shown in Figure 4, among the data channel group DCG,, also be responsible for transmitting the detection burst PB between adjacent network element except transmitting regular traffic DB.The control grouping DBHP (and PBHP) of DB (and PB) transmits on control channel group CCG.DB enters the data channel group from ingress edge node, straight-through core switching node, and until the outlet edge node, the centre no longer experiences any opto-electronic conversion.PB is then different, and PB can enter the data channel group from arbitrary network element node, but must jump road under the network element node from next, is sent to detection processing module (Probe Process Module) and carries out verification.

One, the form of data burst and detection burst

Fig. 1 is light burst exchange network data burst DB and corresponding data burst control information bag DBHP (Data Burst Header Packet) and surveys burst PB (Probe Burst) and corresponding control grouping bag PBHP (Probe Burst Header Packet) the data structure schematic diagram of surveying burst.Wherein Fig. 1 (a) is the signal format of DB and DBHP thereof, and the upper-layer service data after convergence processing, have produced data burst DB (Data Burst) and corresponding data burst control grouping DBHP (Data Burst Head Packet) in the burst adaptation layer.The information that comprises among the DBHP generally comprises the source address (Src), destination address (Des) of DB, the wavelength numbering (Wavelength) that will use, size (Size) and the offset time contents such as (Offset time) of DB, and it is that the physical layer that is sent to Control Network transmits.And DB is sent to data network as payload, and therefore it also often be called " passing network " generally not for the control part branch of node reads or rewrites data transparency.Different with DB, the payload of surveying burst is by converging generation, it is produced according to malfunction monitoring principle and coding principle etc. by detection processing module (Probe Module), ability with very strong sudden error code of monitoring, the signal format of PB and PBHP thereof is shown in Fig. 1 (b), it adopts the burst format identical with DB, comprise identical controlling packet form and payload format, in payload part, what fill is not upper-layer service, but an explore frame, this frame has the ability of the very strong sudden error code of monitoring, and node is distinguished PB and DB distinguishes by the type in the controlling packet (type) byte.

Two, the handling process of burst packets

Shown in Fig. 2 (a), in the transmission part (edge Ingress node) of fringe node.Convergence module (Assembler) is finished the converging of business datum, and forms DB; Detecting module (Probe Module) generates PB according to established rule, and in the time of DB or PB generation, BHP maker (BHP Generator) produces corresponding burst control bag, and the burst control bag of DB is DBHP, and the burst control bag of PB is PBHP.At this moment, the control of signal of telecommunication form divides into groups to become light signal and be sent to the control channel group through the E/O conversion.After offset time arrived, offset time manager (Offset Manager) control scheduler sent burst.At this moment, the burst group of signal of telecommunication form becomes light signal and is sent to the data channel group through the E/O conversion.Shown in Fig. 2 (b), at fringe node receiving unit (edge Egress node), the signal on the optical fiber is received machine and converts the signal of telecommunication (O/E conversion) to.The outburst type information that BHP processor (BHP Processor) provides according to BHP, the control figure Cross Connect equipment is sent to DB and separates convergence module (disassembler), and PB is sent to the detection processing module.

Fig. 3 is the core node functional structure chart of band detecting module.At the core switching node, switching control unit SCU receives the BHP on the control channel, according to address among the BHP and wavelength information, and configuration optical cross-connection equipment OXC, make the corresponding DB on the data channel be switched to correct outlet wavelength, or the edge Egress node is sent on the road down.If that SCU handles is PBHP, so just control OXC PB is exchanged to detecting module, handle by detecting module and survey burst, the data channel performance is assessed.SCU also can produce desire and survey the PBHP of outlet wavelength channel and notify detecting module to prepare PB according to the requirement of management or control plane, and after suitable offset time, SCU control OXC dispatches corresponding PB and sends to corresponding outlet wavelength.Dotted line among Fig. 3 represents that control channel is a wavelength or the several wavelength (control channel group CCG) in all wavelengths channel.Available Fig. 4 represents this decoupling zero relation of data channel group (DCG) and control channel group among the OBS.What be worth prompting a bit is that PB is generally shorter, and survival period has only a jumping; And DB is generally long, and its survival period generally has multi-hop from the Ingress node to the Egress node.

Edge and core node at light burst exchange network all can be finished generation, transmission, the reception of surveying burst and judge network performance.

Three, fault monitoring process

Survey the explore frame of encapsulation in the burst, can adopt fixing bit pattern, receiving terminal only needs the explore frame that encapsulates among the PB is compared with standard pattern after receiving PB, and just the mistake among the PB is a random error as can be known, or unexpected error.As shown in Figure 5.Take out PB at the next-hop network node that sends the PB node, and the bit among the PB carried out verification, its error condition of statistical analysis, deposit the error situation statistical log in, if the frame format that receives is incorrect, or unexpected error is arranged in the explore frame or should receive PB and when not receiving according to PBHP, the capital causes forward-backward counter to add one, but, if when next receiving correct frame again, just forward-backward counter subtracts one, when count value increases, when surpassing the hard fault alarming threshold that sets in advance, the expression error code extremely worsens, and network element is just sent hard fault and alarmed to protection recovery module; The mistake frame number that the statistics random error causes, the wrong frame number in the unit interval, and compare analysis with historical records such as former mistake frame number, frame error rate, if error condition exceeds the soft fault alarming threshold, network element is just sent soft fault and is alarmed to network management center so.If the random error rate is constantly soaring, often shown the constantly aging of device.

The present invention can be reflected to the fault of photosphere rapidly the electricity layer by surveying burst.It can provide warning information fast and accurately for needed quick protective switch of network survivability or recovery; It can also be management maintenance purpose fault location, and accurately detailed soft or hard fault message is provided.And it is applicable to any network size, any network topology and control mode, and autgmentability is good.

Claims (4)

1. the performance of a light burst exchange network and fault monitoring method is characterized in that, produce the control grouping bag PBHP of detection burst PB and detection burst at each network element node of light burst exchange network; Under control plane or management plane control, periodically on the data channel that desire is surveyed, send PB, and on control channel, send corresponding PBHP in advance with fixed bit pattern explore frame; Receive and take out PB at next the jumping network element node that sends PB; Bit pattern among the PB is carried out verification, its error condition of statistical analysis; If exceed the fault warning thresholding, network element is just sent warning information.

2. performance according to claim 1 and fault monitoring method is characterized in that, survey generation, transmission, the reception of burst and all finish at the edge and the core node of light burst exchange network.

3. performance according to claim 1 and fault monitoring method is characterized in that the survival period of described detection burst has only a jumping.

4. according to claim 1-3 one of them described performance and fault monitoring method, it is characterized in that,, send the hard fault warning information and recover module for protection if error condition exceeds the hard fault alarming threshold; If error condition exceeds the soft fault alarming threshold, send the soft fault warning information and give network management center.

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