CN1976305A - Scalable selective alarm suppression for data communication network - Google Patents

Abstract

Scalable selective alarm suppression is achieved through a new class of management packet, such as a new class of Ethernet management frame, adapted to convey a reachability relationship between a lower level maintenance point and a single higher level maintenance point, and more particularly adapted to convey to a first higher level maintenance point that receives the packet an identity of a single second higher level maintenance point that will become unreachable to the first higher level maintenance point in the event of a loss of continuity involving the lower level maintenance point. Once the first higher level maintenance point has learned a totality of operative reachability relationships through receipt of such packets and is notified of a loss of continuity involving the lower level maintenance point, the first higher level maintenance point can reference the learned reachability relationships and readily determine under what circumstances it should suppress an alarm in response to a detected loss of continuity with a higher level maintenance point.

Description

The scalable selective alarm that is used for data communication network suppresses

The cross reference of related application

The application requires the U.S. Provisional Application No.60/691 of submission on June 17th, 2005,491, the U.S. Provisional Application No.60/699 that submitted on July 15th, 2005, the U.S. Provisional Application No.60/708 that on August 16th, 678 and 2005 submitted to, 815 priority, these applications all are entitled as " Scalable Accurate AIS " (extendible accurate AIS), comprise the content of all these applications in this mode by reference.

Technical field

The present invention relates to the Trouble Report in the data communication network, and relate more particularly to be used for suppress expanding of alarm and accurate method and system at Ethernet.

Background technology

Whether normally Connectivity Fault Management (CFM) is meant monitor network ability.CFM in the Ethernet is carried out by the network management system (nms) of the application layer protocol of operation such as Simple Network Management Protocol (SNMP) traditionally.In typical NMS based on SNMP, the fault in the Ethernet is acted on behalf of and is detected and be reported to central snmp management device by running on SNMP on the managed data communication node (for example supporting the node of ethernet bridging ability).Usually in response to indivedual polls of SNMP agency are generated Trouble Report, this might be loaded down with trivial details and slowly in having the network of a large amount of managed nodes.Although can be with the SNMP proxy configurations for generating unsolicited Trouble Report, for example correspond directly to fault detect and send signalling trouble to the snmp management device, if experienced catastrophic fault but SNMP acts on behalf of the managed node at place, then the SNMP agency can not send signalling trouble.

In often striding the large-scale Ethernet of a plurality of user networks, provider's network and carrier network, separately the insufficiency that transmits CFM by the NMS based on SNMP has been drawn the development of more healthy and stronger local ethernet CFM solution.This local ethernet CFM solution of just in the IEEE802.1ag of document form (the 802.1ag standard of Institute of Electrical and Electric Engineers), carrying out standardization and being called " Ethernet CFM " hereinafter by band to the ethernet management frame in (in-band) transmission the fault detect and the report of the active that is used for bridged ethernet (bridged Ethernet network) are provided.

In Fig. 1, show the operation of Ethernet CFM by example.Bridged ethernet 100 comprises provider equipment PE1, the PE2 in subscriber equipment CE1, CE2, CE3 and the provider's network in the user network.Subscriber equipment and provider equipment comprise the ethernet bridging ability.Provider equipment PE1, PE2 are safeguarded by the service provider.Subscriber equipment CE1, CE2, CE3 safeguard by service provider's user, and CE1 communicates by provider equipment PE1 and PE2 and CE2 and CE3.User network also comprises the customer network management, CNM system (CE NMS) 110 of the fault that is used for the supervisory user network, and provider's network comprises provider's network management system (PE NMS) 120 of the fault that is used for monitoring provider's network.

Configuring maintenance association (MA) on different maintenance levels is so that carry out CFM.In the example shown, configure user maintenance association (CMA) 115 on user class is to carry out CFM in user network.CMA 115 comprises maintaining end point (MEP) A, D, E and Maintenance Intermediate Point (MIP) B, C.Configuration provider's maintenance association (PMA) 125 on provider's level is to carry out CFM in provider's network.PMA 125 comprises MEP F and MEP G.MEP and MIP are software entity or the hardware entities of creating on every node or every port basis.Generally speaking, MEP sends and receives the ethernet management frame in its corresponding M A, optionally reports to the fault of NMS to detect, so that can take the measure of correcting.When MEP detects fault and gives NMS with this Trouble Report, think that MEP has sent alarm.When MEP detects fault but do not have to give NMS with this Trouble Report, think that MEP has suppressed alarm.

MEP comes infer fault according to having lost with the continuity of other MEP.In the example shown in Figure 1, owing to continuity check (CC) frame of failing to receive from MEP F, MEP G detects fault on PMA 125.Generally speaking, the CC frame is to send between the MEP in MA to confirm the important messages with the connectedness that sends MEP (sending MEP).Detecting fault makes MEP G send the signalling trouble of this fault of report to PE NMS 120 by SNMP.Detect fault and also make MEP G in CMA 115, send alarm indication signal (AIS) frame, with to the more rudimentary fault of MEP D and MEP E circular, thereby and in CMA 115, cause inhibition alarm.If in CMA 115, do not send the AIS frame, then MEP D will detect identical fault and will report these faults to CE NMS 110 with MEP E owing to the CC frame of failing to receive from MEP A, even CE NMS 110 does not carry out any operation control to the provider's network that has this fault.Owing to sent the AIS frame in CMA 115, so MEP D and MEP E have suppressed the alarm among the CMA 115 and avoid sending unnecessary report to CE NMS 110.

Accuracy when below detecting different faults among the MA that a problem suppressing of the Ethernet CFM alarm of usually describing is it on operating in not at the same level such as PMA 125 and CMA 115.Consider a kind of situation, wherein detect more rudimentary fault among the PMA 125 between MEP F and MEP G, and detect higher fault among the CMA 115 between MEP D and MEP E subsequently.When this happens, should forbid to CE NMS 110 reports more rudimentary (on this level ideally by the AIS frame that MEP G sends in CMA 115, CE NMS 110 does not move control) fault, but should not forbid fault to CE NMS 110 reports more senior (on this level, CE NMS 110 moves control).A kind of possible solution of this problem comprised to MEP D and MEPE the getatability relation is provided that according to this relation, MEP D and MEP E can distinguish that higher MEP A becomes and can not arrive the result that fault caused who relates to more rudimentary MEP F.Under the situation of understanding this getatability relation, MEP D and MEP E can suppress owing to fail to receive the alarm that the CC frame from the CC frame of MEP A causes, generation simultaneously is owing to failing to receive the alarm that causes from each other CC frame.

A kind of known realization (being called non-selective AIS) that Ethernet CFM alarm suppresses can not provide the getatability relation, and does not therefore solve the problem of distinguishing the fault on a plurality of levels.As an alternative, in response to from the more rudimentary AIS frame that receives, on more senior, suppress all alarms.

The another kind of known realization (being called selectivity AIS) that Ethernet CFM alarm suppresses is not easy to expand.In a kind of selective alarm suppresses to realize, more rudimentary MEP monitors the CC frame that (snoop) sent by higher MEP, under the situation that is informed in the fault that relates to more rudimentary MEP, which more senior MEP will become can not arrive other more senior MEP.More rudimentary MEP sends the complete list of the more senior MEP that can not arrive conditionally in sending to the CC frame of another more rudimentary MEP.Under the situation of the fault that relates to more rudimentary MEP, the more rudimentary MEP that receives this tabulation sends the complete list of the more senior MEP that can not arrive conditionally to other more senior MEP in the AIS frame, so that other more senior MEP can suppress the alarm that causes owing to the CC frame of failing to receive from the more senior MEP in this tabulation.In having the network of a large amount of MEP, the complete list of this more senior MEP that can not arrive conditionally that sends in CC frame and AIS frame may have high bit count and make these frames not meet MTU (MTU) size that is used for Ethernet.

Summary of the invention

The present invention provides the extendible selective alarm of the data communication network that is used for such as Ethernet to suppress in essential characteristic.Extendible selective alarm suppresses and can realize by the new supervisory packet of a class (such as the new ethernet management frame of a class), the supervisory packet that this class is new is suitable for transmitting the getatability relation between more rudimentary maintenance point and the single more senior maintenance point, and more particularly is suitable for will becoming under the first more senior maintenance point that receives this bag is transmitted in the situation of the Loss of continuity that relates to more rudimentary maintenance point the sign of the second single more senior maintenance point that can not arrive concerning the first more senior MEP.In case the first more senior maintenance point is known whole exercisable getatability relations by this bag, and the Loss of continuity that will be referred to more rudimentary maintenance point is circulated a notice of to this first more senior maintenance point, and then when this first more senior maintenance point can and easily be determined with reference to this known getatability relation and should suppress alarm with the connectedness of more senior maintenance point in response to detecting to have lost.

In one aspect, a kind ofly be used for carrying out the method that selective alarm suppresses and comprise:, store first maintenance point and concern with a plurality of getatabilities between corresponding a plurality of second maintenance points in response to corresponding a plurality of supervisory packets at data communication network; Detection is about first Loss of continuity of first maintenance point; Detection is protected a little second Loss of continuity about the third dimension; Whether and to protect based on the third dimension at least in part be that one of a plurality of second maintenance points determine whether to produce the alarm about second Loss of continuity a little.

In another aspect, a kind of data communication node that is applicable to that selective alarm suppresses has interface, memory and the management entity that is suitable for carrying out this method.

In another aspect, a kind ofly be used for carrying out the method that selective alarm suppresses at data communication network and comprise: receive first supervisory packet, it comprises that second of first sign of first maintenance point and second maintenance point identifies; The getatability of storing between first maintenance point and second maintenance point in response to this first supervisory packet concerns; Reception shows second supervisory packet about first Loss of continuity of first maintenance point; Detect about the third dimension and protect a little second Loss of continuity based on failing in the time of expection, to receive the 3rd supervisory packet at least in part; And use this getatability to concern to determine whether to produce alarm about second Loss of continuity.

In another aspect, a kind of being used for realizes that at data communication network the method that selective alarm suppresses comprises: produce supervisory packet, it comprises first sign of first maintenance point and second sign of second maintenance point; And this supervisory packet is sent to the third dimension protect a little, this third dimension is protected a little to be suitable for storing in response to this supervisory packet the getatability relation between first maintenance point and second maintenance point and to use this getatability to concern and is determined whether to produce the alarm of protecting Loss of continuity a little about detected relevant fourth dimension.

In aspect another, a kind of being applicable to realizes that in data communication network the data communication node that selective alarm suppresses comprises: first interface, and it is suitable for receiving the supervisory packet of second sign with second maintenance point; Management entity, it is suitable for storing first sign of first maintenance point in this supervisory packet; And second interface, it is suitable for that this supervisory packet is sent to the third dimension and protects a little, and this third dimension is protected a little to be suitable for storing in response to this supervisory packet the getatability relation between this first maintenance point and this second maintenance point and to use this getatability to concern and determined whether to produce the alarm of protecting Loss of continuity a little about the detected relevant third dimension.

By with reference to the detailed description of carrying out, will understand these and other aspects of the present invention better below in conjunction with accompanying drawing (below will be briefly described) to it.Certainly, the present invention is limited by appended claims.

Description of drawings

Fig. 1 shows the network of operation Ethernet CFM.

Fig. 2 shows the path of exemplary support AIS (S-AIS) frame in the network of the operation Ethernet CFM in one embodiment of the present of invention.

Fig. 3 shows the path of exemplary continuous inspection (CC) frame in the network of the operation Ethernet CFM in one embodiment of the present of invention.

Fig. 4 shows the network of the operation Ethernet CFM in one embodiment of the present of invention, and this network has experienced the first exemplary fault.

Fig. 5 shows the response to exemplary first fault in the network of the operation Ethernet CFM in one embodiment of the present of invention.

Fig. 6 shows the response to exemplary second fault in the network of the operation Ethernet CFM in one embodiment of the present of invention.

Fig. 7 shows the operation Ethernet CFM in the second embodiment of the invention and has the network of protected path.

Fig. 8 shows the operation Ethernet CFM in the second embodiment of the invention and has CC/AIS contradiction in the network of protected path.

Fig. 9 shows the operation Ethernet CFM in the third embodiment of the invention and has the path of the exemplary S-AIS frame in the network of stitching maintenance association (SMA).

Figure 10 shows the operation Ethernet CFM in the third embodiment of the invention and has the network of SMA.

Figure 11 is the flow chart that the operation of the maintaining end point (MEP) in one embodiment of the present of invention is shown.

Embodiment

Mention, by know the whole getatability relations between more rudimentary maintenance point and other the more senior maintenance point by a more senior maintenance point, and more particularly be informed in the sign that will become other more senior maintenance points that can not arrive under the situation of the Loss of continuity that relates to more rudimentary maintenance point, can realize that selective alarm suppresses by a more senior maintenance point.In one embodiment of the invention, extendible selective alarm suppresses to realize by the ethernet management frame of one or more novelties, these ethernet management frames are called at this supports AIS (S-AIS) frame, received before losing continuity by more senior maintenance point, and each frame all is suitable for transmitting the getatability relation between more rudimentary maintenance point and the single more senior maintenance point.

In Fig. 2, show the path of this S-AIS frame in the network 200 that moves Ethernet CFM in one embodiment.Network 200 comprises provider equipment PE3, the PE4 in subscriber equipment CE4, CE5, CE6, CE7 and the provider's network in the user network.Subscriber equipment and provider equipment are the data communication nodes such as Ethernet switch, it has the interface that is used to send and receive the message bag such as Ethernet data and management frames, and its form with the combination of logic, software or the logical AND software of customization is supported ethernet bridging ability and maintenance entity.Provider equipment PE3, PE4 are safeguarded by the service provider.Subscriber equipment CE4, CE5, CE6, CE7 are safeguarded by service provider's user.And CE4 and CE5 communicate by provider equipment PE3, PE4 and CE6, CE7.Configuring maintenance association (MA) on different maintenance levels is so that carry out CFM.Configure user maintenance association (CMA) 215 on user class is to carry out CFM in user network.CMA 215 comprises maintaining end point (MEP) H, I, J, K that represents with triangle and Maintenance Intermediate Point (MIP) L, the M that represents with circle, and it can be operated on CE4, CE5, CE6, CE7 and PE3, PE4 respectively.Configuration provider's maintenance association (PMA) 225 on provider's level is to carry out CFM in provider's network.PMA 225 comprises the MEP N and the MEP O that can operate respectively on PE3, PE4.MEP and MIP are the entities that the software/hardware with logic, software or the mixing of customization created on every node or every port basis is realized.For example, can see, respectively configuration MEP I and MEP K on the port of CE5 and CE7.MEP sends and receives the ethernet management frame in its corresponding M A, optionally report to the fault of network management system (nms) to detect, so that can take the measure of correcting.MIP transmits the ethernet management frame (for example CC frame) of some type that receives from MEP passively, and the ethernet management frame (such as loopback frame and link trace frame) of other types is responded.

The S-AIS frame is a kind of type of message, each MEP in MA between reciprocally and aperiodically send this type of message, to know the sign (if present) that sends the more rudimentary MEP between MEP and the reception MEP at each.Based on the S-AIS frame that receives from whole other MEP, each MEP can know that the MEP of every other same stages and the getatability between the more rudimentary MEP concern.MEP is being carried out in the initialization, and MEP when MEP receives the S-AIS frame of the MEP that makes a fresh start or receives the S-AIS frame with fresh information, sends S-AIS frame by MEP by CC frame/when AIS frame contradiction detects topology change.In certain embodiments, send MEP and can initiate to have S-AIS frame source MEP identifier field (S-MEP ID) and that be initially empty rudimentary MEP identifier field (B-MEP ID) that identifies himself.Having first of the more rudimentary MEP that is associated receives sign that MIP (if present) will more rudimentary MEP and is inserted among the B-MEP ID and this frame is transmitted to one or more reception MEP.Recording needle is to sending the getatability relation of MEP separately to receive MEP, and this getatability relation will more rudimentary MEP (identifying in B-MEPID) be designated to be arranged in and sends between MEP (identifying at S-MEP ID) and the reception MEP.By the whole S-AIS frames that received with the aforementioned manner analysis, each more senior MEP advantageously is informed in the group that will become the more senior MEP that can not arrive under the situation of the Loss of continuity that relates to more rudimentary MEP at each more rudimentary MEP.

In other embodiment, can comprise that by being revised as the B-MEP ID that identifies rudimentary MEP initiates the S-AIS frame type by MIP by the CC frame type that MEP initiates.In these embodiments, MEP can not initiate to have the S-AIS that is initially empty B-MEP ID.

In certain embodiments, in the example, the transmission of S-AIS frame is carried out as follows shown in figure 2.The S-AIS frame that MEP I initiates to have the S-MEP ID that identifies itself and is initially empty B-MEP ID.MEP I gives adjacent maintenance point MEPH and MIP L with this frame multileaving.MEP H recording needle is to the getatability relation of the sky of MEP I.For example, in one embodiment, storage or renewal are at the clauses and subclauses of MEP I in the getatability table of MEP H on CE4, and these clauses and subclauses show does not have MEP between MEP H and MEPI among the PMA 225.On the other hand, MIP L has the MEP that is associated on more rudimentary.Therefore, MIP L inserts the sign of MEP N and this frame is transmitted to MEP J and MEP K in B-MEP ID.MEP J and MEP K separately recording needle to the getatability of the non-NULL of MEP I relation.For example, in one embodiment, storage or upgrade clauses and subclauses in the getatability table of MEP J on CE6 at MEP I, these clauses and subclauses show that MEP N among the PMA 225 is between MEP J and MEP I.Similarly, storage or upgrade clauses and subclauses in the getatability table of MEP K on CE7 at MEP I, these clauses and subclauses show that MEP N among the PMA 225 is between MEP K and MEP I.The getatability table can be realized in random-access memory (ram).

Forward Fig. 3 to, wherein show the path of continuity check (CC) frame in the network 200 in one embodiment.The CC frame is a kind of type of message, each MEP in MA between reciprocally and termly send this type of message, to confirm and the continuous connectedness that sends MEP.MIP transmits the CC frame passively.For example, MEP I initiates to have the CC frame of the sign of this MEP I in S-MEP ID.MEP I gives adjacent maintenance point MEP H and MIP L with this frame multileaving.MEP H record is to from the reception of the CC frame of MEP I and timer is resetted.MIP L is transmitted to MEP J and MEP K via MIP M with this CC frame passively, wherein MEP J and MEP K recorder and timer is resetted in a similar fashion.Repeat this process termly at CMA 215 and PMA 225, with the continuous connectedness between the MEP that confirms all same stages on the cycle of operation of network 200.

Forward Fig. 4 to, wherein network 200 is depicted as and has experienced first fault (fault 1).Fault can be for example link failure or framework fault.Fault 1 has interrupted the connectedness between PE3 and the PE4 and has stoped receiving some CC frame on CMA 215 and PMA 225.For example, in CMA 215, MEP H and MEP I can not receive the CC frame from MEP J and MEP K, and vice versa.In PMA 225, MEP N can not receive the CC frame from MEP O, and vice versa.Failing to receive the CC frame in the time of expection makes MEP enter the Loss of continuity state.For example, after MEP J failed to receive expeced time from the CC frame of MEP I, MEP J entered the Loss of continuity state.Under the Loss of continuity state, MEP J can other MEP or MIP on CMA 215 send one or more link trace frames or loopback frame, so that with bigger accuracy fault is positioned.Under some environment that will inquire into hereinafter, MEP J can also send report by for example snmp message and lose the alarm of circulating a notice of fault 1 to NMS with successional alarm indication signal (AIS) frame and the initiation of MEP I.

Forward Fig. 5 to, wherein show the path of the AIS frame that the fault in the network 200 1 is responded in one embodiment.The AIS frame is a kind of type of message that is optionally sent by the MEP that enters the Loss of continuity state.Can in the more senior MA of the MA of the MEP that detects Loss of continuity neutralization, send the AIS frame.The MEP that is under the Loss of continuity state initiates to have the AIS frame of losing MEP identifier field (L-MEP ID), loses with the continuity of sign MEP.

In certain embodiments, in the example shown in Figure 5, the transmission of AIS frame is carried out as follows.As the result of fault 1, CC frame and MEP O that MEP O fails to receive from MEP N in the time of expection enter the Loss of continuity state.Under the Loss of continuity state, MEP O initiates to have the AIS frame of the L-MEP ID that identifies MEP N.MEPO gives PE NMS 520 with this malfunction notification, so that can take the measure of correcting.For example can be undertaken for PE NMS 520 by the snmp message that sends sign fault 1 to PE NMS 520 Trouble Report.MEP O also sends the AIS frame to the more senior MIP M that is associated, and this MIP M is transmitted to MEP J and MEP K with this AIS frame passively.MEP J and MEPK analyze this AIS frame separately and write down the Loss of continuity that relates to MEP N.For example, in one embodiment, storage or renewal are at the clauses and subclauses of MEP N in the Loss of continuity table of MEP J on CE6, and this table of articles is understood the Loss of continuity that relates to MEP N.MEP K carries out same operation on CE7.The Loss of continuity table can be realized in RAM.Should be noted that under the situation that in PMA 225, has accessibility adjacent maintenance point that MEP O also should give adjacent maintenance point with this AIS frame multileaving.

The another one consequence of fault 1 is that CC frame and MEP J that MEP J fails to receive from MEP H and MEP I in the time of expection enter the Loss of continuity state.Consider the example of the Loss of continuity between MEP I and the MEP J.MEP J determines at first whether Loss of continuity is the result of more rudimentary fault.MEP J is with reference to its Loss of continuity table and determine to have had the Loss of continuity of having reported that relates to more rudimentary MEP N.Then, MEP J determines also that with reference to its getatability table this more rudimentary MEP N is between MEP J and MEP I.Therefore, MEP J reaches a conclusion, and promptly this Loss of continuity is the result of more rudimentary fault, and suppresses alarm, otherwise this alarm meeting conduct produces with the result of the Loss of continuity of MEP I.More particularly, MEP J has avoided fault 1 is reported to CE NMS 510.MEP J has also avoided issue to have the AIS frame of the L-MEP ID of sign MEP J.Should recognize, MEPK has imitated and has caused the similar procedure that alarm suppresses, otherwise this alarm meeting is owing to the continuity of losing with MEP I produces, and MEP J, MEP K imitated and cause the similar procedure that alarm suppresses, otherwise this alarm meeting is owing to its continuity of losing with MEP H produces.

Forward Fig. 6 to, wherein show response in one embodiment second fault (fault 2) that is experienced in the network 200.As the result of fault 2, CC frame and MEP K that MEP K fails to receive from MEP J in the time of expection enter the Loss of continuity state.MEP K determines at first whether this Loss of continuity is the result of more rudimentary fault.MEP K is with reference to its Loss of continuity table and determine to have had the Loss of continuity of having reported that relates to more rudimentary MEP N.Then, MEP K determines also that with reference to its getatability table this more rudimentary MEP N is not between MEP K itself and MEP I.Therefore, MEP K reaches a conclusion, and promptly this Loss of continuity is not the result of more rudimentary fault, and produce about with the alarm of the Loss of continuity of MEP J.More particularly, MEP K for example reports to CENMS 510 via SNMP with fault 2, so that take the measure of correcting.Should recognize, under the situation of the more senior MIP that has accessibility adjacent maintenance point and/or be associated in CMA 215, MEP J also should initiate to have the AIS frame of the L-MEP ID that identifies MEP J and give adjacent maintenance point among the CMA 215 and/or the more senior MIP that is associated with this AIS frame multileaving.

At this moment, should be understood that, it all is optionally that above-mentioned alarm suppresses strategy, reason is that it has suppressed about being attributable to the low alarm of safeguarding the Loss of continuity of level, and it all is extendible that above-mentioned alarm suppresses strategy, and reason is its sign that need not transmit a plurality of nodes of the object that concerns as getatability in single bag.The various modifications that this basic alarm suppressed strategy will be described now.Yet, basically, can think that described alarm so far suppresses strategy and has obvious improvement with respect to the non-selective of prior art and the method that can not expand.

Mention that when MEP detected the topology change that causes owing to CC/AIS contradiction, this MEP sent the S-AIS frame.Fig. 7 and Fig. 8 show the exemplary contradiction between CC frame and the AIS frame, and this contradiction has shown impels the topology change that sends the S-AIS frame.

Forward Fig. 7 to, the network 700 that moves Ethernet CFM and have protected path wherein has been shown in the second embodiment of the present invention.Network 700 is similar with network 200 in configuration, and only network 700 has the main core provider equipment Pp that inserts between provider equipment PE3 and the provider equipment PE4 and the core provider equipment Pb of backup.At first, provider equipment PE3 can be connected by main core provider equipment Pp communicatedly with provider equipment PE4.The CC frame transmits between MEP H and MEP I on the one hand, and main core provider equipment Pp transmission between MEPJ and MEP K on the other hand.Yet the fault (FAULT) on the main core provider equipment Pp can temporarily be interrupted the transmission to the CC frame.

Forward Fig. 8 to, wherein show in network 700 as the CC/AIS contradiction of recovering between PE3 and the PE4 that produces via the result who communicates to connect of Pb.FAULT on the Pp can temporarily interrupt the connectedness between PE3 and the PE4, and temporarily stops some CC frame of reception on CMA 215 and PMA 225.For example, in CMA 215, MEP H and MEP I can not receive the CC frame from MEP J and MEP K, and vice versa.In PMA 225, MEP N can not receive the CC frame from MEP O, and vice versa.Failing to receive the CC frame in the time of expection makes MEP enter the Loss of continuity state.For example, under the Loss of continuity state, MEP O initiates to have the AIS frame of the L-MEPID that identifies MEP N.MEP O sends to the more senior MIP M that is associated with this AIS frame, and this MIP M is transmitted to MEP J and MEP K with this AIS frame passively.MEP J and MEP K analyze this AIS frame separately and write down the Loss of continuity that relates to MEP N.Yet in case recovered connectedness between PE3 and the PE4 via Pb, MEP J and MEP K will receive the CC frame of initiating from MEP H and MEP I once more.Therefore, MEP J and MEP K detect contradiction.On the one hand, when considering when putting together, the loss of connectivity table of MEP J and MEP K and getatability table show that MEP H and MEP I can not arrive, and but then, MEP J and MEP K are receiving the CC frame from MEP H and MEP I again.MEP J and MEP K infer according to this detected contradiction topology change have taken place, and therefore send the S-AIS frame.

When provider's network is striden a plurality of operator, adopt selective alarm described here to suppress strategy and can produce a difficult problem.With reference now to Fig. 9 and Figure 10, study solution to a this difficult problem, this solution relates to inserting between PMA and operator's maintenance association (OMA) sews up maintenance association (SMA).

Forward Fig. 9 to, operation Ethernet CFM wherein has been shown in third embodiment of the invention and has had the path of the S-AIS frame in the network 900 of stitching maintenance association (SMA) 925.Network 900 comprises provider equipment PE 5, PE 6 and the equipment OA1 of operator, OA2 in first carrier network and the equipment OB1 of operator, the OB2 in second carrier network in provider's network.Provider equipment and operator's equipment are the data communication nodes of the support ethernet bridging ability such as Ethernet switch.Provider equipment PE5, PE6 are safeguarded by the service provider.The equipment OA1 of operator, OA2 are safeguarded by first operator, and the equipment OB1 of operator, OB2 are safeguarded by second operator.The service provider is the client of operator.PE5 and PE6 communicate by the equipment OA1 of operator, OA2, OB1, OB2.Configuring maintenance association (MA) on different maintenance levels is so that carry out CFM.Configuration provider's maintenance association (PMA) 915 on provider's level is to carry out CFM in provider's network.Configuration first operator's maintenance association (OMA1) 935 on carrier-class is to carry out CFM in first carrier network.Configuration second operator's maintenance association (OMA2) 945 on carrier-class is to carry out CFM in second carrier network.PMA 915 comprises MEP P, the MEPU that can operate respectively and MIP Q, MIP R, MIP S, MIP T on PE5, PE6, OA1, OA2, OB1, OB2.OMA1 935 comprises the MEP Z that can operate respectively on OA1, OA2.OMA2945 comprises MEP b, the MEP c that can operate respectively on OB2, OB1.

Under the situation that does not have SMA 925, the difficult problem that must solve is incomplete corresponding by between S-AIS frame more rudimentary MEP that reports and the more senior MEP that reports by the AIS frame.For example, under the situation that does not have SMA 925, the S-AIS frame that MEP U can initiate to have sign MEP U self and be initially empty B-MEP ID.MEP U can send to this frame MIP T.MIP T can insert the sign of rudimentary MEP c and send this frame to MIP S in B-MEP ID, MIP S can send to this frame MEP P.MEP P can the getatability table on PE5 in storage at the clauses and subclauses of MEP U, these clauses and subclauses show that MEP c is between MEP P and MEP U.Yet MEP P can not know that MEPa is also between MEP P and MEP U according to the S-AIS frame.Therefore, if MEP P will be known first Loss of continuity (for example AIS frame by being initiated by MEP Z) that relates to MEP a and know second Loss of continuity (for example according to failing to receive the AIS frame from MEP U in the time of expection) that relates to MEP U, even then by more rudimentary fault cause that with the Loss of continuity of MEP U MEP P also can can't suppress the alarm at the fault that relates to MEP U improperly.

For solving this difficult problem, the service provider inserts SMA 925 between PMA 915 and the OMA1 935 on the one hand, inserts on the other hand between PMA 915 and the OMA2 945.SMA925 is abstract maintenance level, and it is stitched together OMA1 935 and OMA2 945 effectively, so that can carry out correct coordination between S-AIS and AIS frame.For example, as shown in Figure 9, in one embodiment, the S-AIS frame that MEP U initiates to have the S-MEP ID of sign MEP U self and is initially empty B-MEP ID.MEP U sends to MIP T with this frame.MIP T inserts the sign of MEP Y and this frame is transmitted to MEP P in B-MEP ID.MEP P stores the clauses and subclauses at MEP U in the getatability table of PE5, these clauses and subclauses show that MEP Y among the SMA 925 is between MEP P and MEP U.With reference now to Figure 10,, because SMA 925 is inserted as level of abstraction, the Loss of continuity of being reported by MEP Z that relates to MEP is suppressed in SMA 925.In addition, if MEP V will be to MEP P report Loss of continuity, then the AIS frame can identify MEPY in L-MEP ID.If MEP P will detect the Loss of continuity with MEP U subsequently, then this MEP P can determine more rudimentary MEP Y between this MEP P and MEP U, and reach a conclusion that promptly this Loss of continuity is the result of more rudimentary fault with reference to its getatability table.Therefore, MEP P can correctly suppress alarm, otherwise this alarm meeting conduct produces with the result of the Loss of continuity of MEP U.

Forward Figure 11 at last to, the flow chart of the MEP operation shown in it in one embodiment of the invention.Receive the S-AIS frame (step 1110) of MEP reception from the MEP of every other same stages.Each S-AIS frame comprises transmission MEP among the S-MEP ID and more rudimentary MEP or the null value among the B-MEPID.Receiving MEP analyzes each S-AIS frame and storage and concerns (step 1120) at the getatability of this transmissions MEP.Each getatability relation will send the more rudimentary MEP (if present) that is identified among MEP and the B-MEP ID and be associated.Especially, the getatability relation is designated more rudimentary MEP between transmission MEP and reception MEP.Then, receive the AIS frame (step 1130) of MEP reception from more rudimentary MEP.This AIS frame comprises L-MEP ID, and the continuity of its sign MEP is lost.Receive MEP record Loss of continuity.Then, receive MEP and detect Loss of continuity (step 1140) with the MEP of same stages according to failing in the time of expection, to receive CC frame from the MEP of same stages.Then, receive MEP with reference to the getatability table and determine and more rudimentary MEP that whether MEP of the same stages that continuity between it has been lost is identified in L-MEP ID after (step 1150).And if after the more rudimentary MEP that in L-MEP ID, identified of the MEP of the same stages of having lost of the continuity between it, then receive MEP suppress about and the alarm (step 1160) of the MEP of continuity between it same stages of having lost.And if after the more rudimentary MEP that in L-MEP ID, do not identified of the MEP of the same stages of having lost of the continuity between it, then receive MEP and produce alarm (step 1170) about the MEP of this same stages.

Those of ordinary skill in the art should recognize, under the situation that does not depart from essence of the present invention and essential characteristic, and can be with the present invention of other particular form specific implementations.Therefore, no matter from which side, this specification all should be considered as illustrative and be nonrestrictive.Scope of the present invention shows by appended claims, and the institute in the implication of the equivalent form of value of the present invention and the scope changes and all will be included in the scope of the present invention.

Claims (10)

1. one kind is used for carrying out the method that selective alarm suppresses at data communication network, comprising:

In response to corresponding a plurality of first supervisory packets, store a plurality of getatability relations between first maintenance point and corresponding a plurality of second maintenance points;

Detection is about first Loss of continuity of described first maintenance point;

Detection is protected a little second Loss of continuity about the third dimension; And

Whether protect based on the described third dimension at least in part is that one of described a plurality of second maintenance points determine whether to produce the alarm about described second Loss of continuity a little.

2. method according to claim 1, wherein said corresponding a plurality of supervisory packets have identified described first maintenance point and corresponding a plurality of described second maintenance points.

3. method according to claim 1 is wherein at least in part based on showing that successional second supervisory packet of having lost with described first maintenance point detects described first Loss of continuity.

4. method according to claim 1 wherein detects described second Loss of continuity based on failing to receive the 3rd supervisory packet that protects a little from the described third dimension in the time of expection at least in part.

5. method according to claim 1 also is included in and determines to produce after the alarm, to network management system report fault.

6. one kind is used for realizing the method that selective alarm suppresses at data communication network, comprising:

Produce supervisory packet, it comprises first sign of first maintenance point and second sign of second maintenance point; And

Described supervisory packet is sent to the third dimension protect a little, the described third dimension is protected a little to be suitable for storing in response to described supervisory packet the getatability relation between described first maintenance point and described second maintenance point and to use described getatability to concern and is determined whether to produce the alarm of protecting Loss of continuity a little about detected relevant fourth dimension.

7. method according to claim 6 wherein before sending described supervisory packet from described second maintenance point, is inserted described supervisory packet with described second sign.

8. method according to claim 6 wherein after described second maintenance point sends described supervisory packet, is inserted described supervisory packet with described first sign.

9. method according to claim 6, wherein before sending described supervisory packet from described second maintenance point, sky sign is inserted described supervisory packet, and after described second maintenance point sends described supervisory packet, described empty sign is revised as comprises described first sign.

10. method according to claim 6, wherein said supervisory packet are the continuity check frames, after described second maintenance point sends described supervisory packet, with described continuity check frame be revised as comprise described first the sign.

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