CN1947375A

CN1947375A - Connectivity fault notification

Info

Publication number: CN1947375A
Application number: CNA2005800091673A
Authority: CN
Inventors: D·莫汉; M·霍内斯
Original assignee: Nortel Networks Ltd
Current assignee: Nortel Networks Ltd
Priority date: 2004-05-25
Filing date: 2005-05-25
Publication date: 2007-04-11

Abstract

Connectivity fault notification is provided by generating an alarm indication signal at a device that is logically adjacent to the fault, and forwarding the alarm indication signal upward through various levels to at least one client level entity. The alarm indication signal may be suppressed at any level for a service instance if service is restored at that level, or if a protection path prevents disruption of the service instance at that level, or auto-suppressed at an originating node based on number of times transmitted or elapsed time. The alarm indication signal may include a point of failure indicator such as the MAC address of the device that generates the alarm indication signal, or a failed resource identity such as an IEEE 802.1 AB LLDP MAC Service Access Point (''MSAP''). Further, the alarm indication signal may be employed to trigger use of the protection path.

Description

Connectivity fault notification

[001] technical field

[002] the present invention generally relates to network communication field, relates in particular to the signalling trouble relevant with failure of connectivity.

[003] cross reference of related application

[004] application number that requires on May 25th, 2004 to submit to is S/N 60/574,253, title is that the U.S. Provisional Patent Application of " METHOD AND SYSTEM FOR CONNECTIVITY FAULT NOTIFICATION (method and system of connectivity fault notification) " and the application number of submission on May 28th, 2004 are S/N 60/575,772, title is the priority of the U.S. Provisional Patent Application of " METHOD AND SYSTEM FORCONNECTIVITY FAULT NOTIFICATION (method and system of connectivity fault notification) ", and the full content of above-mentioned two applications is incorporated herein for your guidance.

[005] background of invention

[006] Ethernet that once only used in local area network (LAN) (" LAN ") environment and other communication protocol are just used in metropolitan area network (" MAN ") and wide area network (" WAN ") now.A reason of this development is that other clients of enterprise and communication service supplier find: it is very convenient to carry out end-to-end operation in their a LAN this locality and environment that can be understood by their IT professional.But, such protocol extension is not originally planned to have shown some problems at interior environment to it.

[007] problem is: single fault just can trigger the alarm of a succession of overwhelming (overwhelm) NMS/OSS.Individual node among the WAN or link for example may be supported than a different business that lan device is much more.Every kind of business that is supported may depend on network nodes a large amount of between end points equally.If intermediate node or link failure will be each alarm generated by service that breaks down.Yet, support other network node of those business also to produce alarm.Therefore, compare with operating on LAN, the possibility of result of single fault can produce too a large amount of alarms.

[008] another problem is the fault location.Need use in for example communication service under the situation of network of a plurality of different service providers, traffic failure may trigger the regulation of service level agreement (" SLA "), these agreements are the contracts between the different service provider, also are the contracts between service provider and its client.According to reason, frequency and the duration of fault, corporate client or the service provider professional cancellation clause of may to one's credit or having the right to enable.Therefore wish the technology that has produce about traffic failure accurately, audible notice perhaps.Described notice also can comprise the indication and the fault location information of failure cause.

[009] summary of the invention

[0010] according to the present invention, a kind of method of connectivity fault notification that provides in network may further comprise the steps: with this fault logic on detect failure of connectivity or failure on the adjacent node, it can comprise and loses continuity and incorrect link; In response to detecting this failure of connectivity or failure, produce an alarm indication signal; And transmit this alarm indication signal at least one client's level entity.Especially, transmit described alarm indication signal to client layer from server layer (it has detected this fault or failure), may be by a plurality of intergrades.Periodically retransmitting this alarm indication signal is suppressed up to this alarm indication signal.For example, can follow this alarm indication signal of inhibition after timer expiration.Alternatively, if the protection path has prevented the destruction to client's connection, then can connect and suppress this alarm indication signal this client.Be noted that and on any rank, suppress alarm indication signal.

[0011] alarm indication signal can comprise point of failure indicator.For example, alarm indication signal can comprise the MAC Address of the equipment that produces alarm indication signal, perhaps fault resource identification, for example IEEE 802.1 ABLLDP MAC Service Access points (" MSAP ").Therefore, the client can determine fault origin according to alarm indication signal easily.Provided by a plurality of service provider network under the situation of a business, this provides the evidence of fault origin easily.Described alarm indication signal can also be used the use in trigger protection path.

[0012] can comprise according to the network equipment of the present invention: can operate detect with this apparatus logic on adjacent failure of connectivity or the circuit of failure, described failure of connectivity or failure can comprise and lose continuity and incorrect link; Can operate the logic that produces alarm indication signal in response to the detection of failure of connectivity; And can operate at least one port from this alarm indication signal at least one client's level entity that transmit.This equipment can be operated and periodically retransmit this alarm indication signal, and for example per second once.This equipment can also comprise can operate the memory of keeping a record, described record comprises the binding of the indication that destination address (" DA "), associated ports and client connect, the indication that described client connects for example is virtual lan (" the VLAN ") sign that is associated with each DA, and the maintaining end point of client's level entity (" MEP ").When detecting fault, it is influenced that this memory can be utilized to determine which client connects, and which port is associated with those business.Only transmit alarm indication signal then via those ports that are associated with the srvice instance that influenced by failure of connectivity.With discussed in detail, when alarm indication signal was clean culture rather than multicast, DA was the most useful as below.

[0013] description of drawings

[0014] Fig. 1 illustrates from more rudimentary technology to more senior delivery network faulty indication.

[0015] Fig. 2 illustrates the form of the AIS of Fig. 1.

[0016] Fig. 3 illustrates the technology of Fig. 1 in the context of network diagram.

[0017] Fig. 4 illustrates alarm inhibition and fault recovery.

[0018] Fig. 5 illustrates optionally and suppresses with nonselective AIS.

[0019] embodiment

[0020] Fig. 1 and Fig. 2 illustrate the technology based on the network failure indication of the business of Ethernet such as VLAN for example that influences of sending.End to end network comprises the first service provider sub-network (100), the second service provider sub-network (102) and the client level entity (104,106) relevant with customer network.During beginning, by with fault logic on adjacent node, for example bridge (110,112) detects fault (108) on ethernet physical layer (" ETY ").Described fault can be link failure, node failure or incorrect link.And this fault can detect on any layer of osi model.In response to the detection of this fault, the node adjacent in logic with faulty link (108) impels generation alarm indication signal (" AIS ") (200).Especially, maintaining end point (" MEP ") (116) on any side of fault all produces AIS (114) separately, and this AIS is transmitted to the MEP that is in the ME level identical with MIP (120) by the Maintenance Intermediate Point (" MIP ") (118) on next higher ME level, use clean culture or multicast.The firm AIS that receives separately, each more senior MEP (120) just can produce more senior accordingly AIS, and this more senior AIS is transmitted to next MEP (122) on more senior by MIP.Similarly, the firm AIS that receives separately, those MEP (122) just can produce more senior AIS, and these more senior AIS are transmitted to the MEP (124) that is associated with client's level entity (104,106) by corresponding M IP.

[0021] periodically retransmits this alarm indication signal and be utilized the inhibition of one of various technology up to it.For example, if this fault has been repaired, just suppress this alarm indication signal.When not receiving X continuously during AIS, client's level equipment assumed fault situation finishes.Alternatively, can suppress this alarm indication signal automatically by the MEP that starts.Especially, can be to the MEP that starts programming so that AIS be sent predetermined times, perhaps only send AIS and reach preset time section according to a count down timer, after this time period, just suppress AIS, and no matter whether failure condition exists.Alternatively, if the protection path has prevented the destruction to client's connection, then can connect and suppress this alarm indication signal this client.Be noted that and on any level, suppress alarm indication signal.Especially, on any given level, MEP may be able to operate by not producing and will be transmitted to next higher corresponding AIS and suppress AIS.When for example having recovered to connect or on certain level, connect not show as when having broken down and can take this operation.But the MEP of that reception is firm to be confirmed this fault (for example determining fault by losing continuity) just this AIS to be transmitted to its higher ME level independently.Alarm suppresses and can also be associated with special client's level entity.In addition, can suppress alarm by action manual, management.

[0022] referring now to Fig. 1 and Fig. 2, AIS comprises target MAC (Media Access Control) address field (200), source MAC field (202), EtherType (VLAN) field (204), VLAN tag field (206), EtherType (OAM) field (208), version field (210), ME level field (212), OpCode field (214), header length field (216), affairs/sequence identifier field (218), transmitting time is stabbed field (220), the following extended field (222) of fixed header, traffic ID TLV (type lengths values) field (224) and other TLV field (226).For AIS, it is not particularly useful that transaction identifiers (218) and transmitting time are stabbed field (220), but still can provide with general frame format.In addition, field (222) is used in the fixing header of expansion in the future version of OAM, and wherein this version is represented by different version field value.Other TLV field (226) can comprise point of failure indicator TLV (228), and the link ID (232) of faulty link or produce the equipment mark of this AIS for example is so that provide trouble isolation serviceability.Especially, AIS startup node can insertion position information, for example the unique mac address TLV (234) of node oneself, perhaps fault resource identification TLV (236), for example IEEE 802.1abLLDP MAC Service Access point (MSAP) (238).If can determine the reason of fault, then AIS startup node can also insert reason indicating device TLV (230) in AIS.

With reference to Fig. 3, each node can keep a record (300) with the form of form or database, so that make things convenient for the generation of AIS and selectivity to send.Every record in this form all can comprise the field (304), expression of destination address (" DA ") field (302), the port that is associated with that DA of expression of MAC Address form by the field (306) of the client entity of the VLAN identification that is associated with that port, represent the field (308) of client's level MEP of being associated.When detecting fault, this fault is associated with the particular port of this node.Described then node can index in the form to identify affected VLAN based on port numbers.Therefore, this node can use the DA that form is discerned all ports and is associated with this affected VLAN.This node will send AIS via each port that is associated with each VLAN then, and described VLAN is associated with the port that detects fault via it.And this node can be when the client ME level MEP on the opposite side of this fault transmits AIS, express which MEP via AIS is isolated in client ME level.Because MEP can determine: as the result of the fault that receives the AIS that is used for it, which reciprocity MEP is isolated, so the too much alarm that has alleviated on client ME level MEP in response to this transmission of the AIS of fault suppresses.Such AIS is referred to as selectivity AIS.Can via specific OAM message pass on server level on the relevant information of client's level MEP that is associated of MEP, described OAM message is used when hope has the AIS of band selectivity alarm inhibition ability functional.In addition, node configuration can be become do not keep this record, and therefore may in the AIS that is sent, not have enough information to go to allow selectivity alarm inhibition information.This AIS is called as nonselective AIS.Under the network topology structure that is associated with affected VLAN is known situation, might utilizes clean culture AIS, and therefore utilize DA.This AIS is called as monobasic AIS, and points to the specific MEP at client ME level place.Otherwise, adopt multicast AIS to be used for optionally or nonselective purpose.Especially, for each affected VLAN sends multicast AIS, because AIS comprises the field that VLAN is specific.

[0023] in illustrated embodiment, network support three different VLAN:S12, S13 and S14.VLAN S12 provides the connectedness between client's level entity CE1 and the client's level entity CE2.VLAN S13 provides the connectedness between client's level entity CE1 and the client's level entity CE3.VLAN S14 provides the connectedness between client's level entity CE1 and the client's level entity CF4.When fault appears among the link P32-PE21, have only VLAN S12 influenced, because the path of working is retained in client's level entity CE1 and client's level entity CE4 and CE3 between the two.Initially on node PE2 and P3, detect the fault among the link P32-PE21.Node PE2 is associated this fault with its port one, node P3 is associated this fault with its port 2.The detection that is not in response to link failure sends corresponding AIS via all of the port, but node PE2 and P3 only send AIS via those ports that are associated with affected VLAN.For example, node P3 determines from its form: a fault effects VLAN S12 who is associated with its port 2, and that VLANS12 also is associated with its port one, and therefore via its port one transmission AIS.Similarly, node PE2 has determined the fault effects be associated with its port one VLAN S12, and that VLAN S12 also is associated with its port 2, and via its port 2 transmission AIS.Client's level entity CE2 receives AIS from node PE2, and signalling trouble timely is provided thus.Node P1 operates in response to the AIS that receives from node P3 via its port 2, be subjected to the influence of the fault that is associated with its port 2 to determine that VLAN S12, and that VLAN S12 is associated with its port one also.Therefore, node P1 transmits corresponding AIS via its port one.In response to the AIS from node P1, node PE1 determines that VLAN S12 is subjected to the influence of the fault that is associated with its port 2, and its port one also is associated with VLAN S12.Therefore, node PE1 transmits corresponding AIS via its port one to client's level entity CE1, and signalling trouble timely is provided thus.Therefore, only propagate AIS to client's level entity CE1 that is associated with the VLAN that is subjected to fault effects and CE2.Skilled person in the art will appreciate that single fault may influence a more than VLAN, and therefore may on each intermediate node, carry out above-mentioned technology.

[0024] Fig. 4 illustrates that wherein an alternative protection path (400) can be in order to recover the fault scenes of affected VLAN in single service provider network.Just begin, adopt link P12-P31 to come supported vlans S12 and VLANS14.When link P12-P31 fault, VLANS12 and VLANS14 are influenced.But, can be along being redirected the traffic carrying capacity that is associated with VLANS12 and S14 from node PE1 to node P2 to the protection path (400) of node P3, so that avoid the link that breaks down.Implement to protect under the situation in path in mode, may need to suppress this AIS message with the destruction of avoiding influenced VLAN.But,, can give client's level entity with the AIS forwards so, even business has finally been recovered in this protection path if implement this protection path in the mode of destroying VLAN really.This network can also be embodied as and make employing AIS produce the enforcement in trigger protection path.In this case, probable value must send AIS in short predetermined amount of time.

[0025] with reference to Fig. 5, VLAN may be associated with more than two client's level entities.For example, VLANS124 is associated with client's level entity CE1, CE2 and CE4.When link P32-PE21 fault, client's level entity CE2 isolates from client's level entity CE1 and CE4.As mentioned above, produce AIS message in response to fault detect.Yet, because VLAN does not have fault fully, so may partially or even wholly suppress alarm.Especially, if client's level entity does not optionally suppress the enough information of alarm according to this in the AIS that receives, so just suppress all alarms.But, can obtain if be isolated among the AIS that is identified at reception of one or more client's level entities of opposite side of fault, so just optionally suppress alarm.For example, when on client's level entity CE1, receiving the AIS relevant and its when the segregate information of client's level entity CE2 is provided with link P32-PE21 fault, client's level entity CE1 can suppress the relevant alarm with client's level entity CE2, but still can report the relevant alarm with client's level entity CE4.

[0026] although the present invention is described by above-mentioned schematic embodiment, those of ordinary skills will appreciate that, under the situation that does not break away from inventive concept disclosed herein, can make illustrated embodiment and revising and change.And, although in conjunction with various illustrated structrual descriptions preferred embodiment, persons skilled in the art will recognize that and can use various special constructions to specialize described system.Therefore, except the scope and spirit of appending claims, the present invention should not be regarded as limited.

Claims

1, a kind of method that is used for providing at network connectivity fault notification comprises step:

With this fault logic on detection failure on the adjacent node;

In response to detecting this failure of connectivity, produce alarm indication signal; And

Transmit this alarm indication signal at least one client's level entity.

2, the method for claim 1 also comprises step from the level of high maintenance entity (ME) more to this at least one client's level entity that transmit this alarm indication signal via.

3, the method for claim 1 also comprises if srvice instance is not destroyed on certain level, and just inhibition is used for the step of transmission of the alarm indication signal of this srvice instance on this grade.

4, the method for claim 1 also comprises if this fault is repaired, and just suppresses to be used for the step of transmission of the alarm indication signal of a srvice instance.

5, the method for claim 1 also comprises the step of the transmission of the alarm indication signal that suppresses to be used for a srvice instance in response to management input.

6, the method for claim 1 also is included in the step of the transmission of the alarm indication signal that suppresses to be used for a srvice instance after the preset time section.

7, the method for claim 1 also is included in the step of the transmission of the alarm indication signal that suppresses to be used for a srvice instance behind the alarm indication signal that periodically sends predetermined quantity.

8, the method for claim 1 also comprises via transmitting the step of this alarm indication signal with each port of the srvice instance associated nodes of this fault effects.

9, the method for claim 1 also comprises the step of transmitting this alarm indication signal via each port of this node.

10, the method for claim 1 also is included in the step of inserting point of failure indicator in this alarm indication signal.

11, method as claimed in claim 10, wherein point of failure indicator comprises MAC Address.

12, method as claimed in claim 10, wherein point of failure indicator comprises the fault resource identification.

13, the method for claim 1, wherein this srvice instance is VLAN (" VLAN ").

14, method as claimed in claim 13 wherein produces different multicast alarm indication signals for each VLAN.

15, method as claimed in claim 13 wherein produces different clean culture alarm indication signals for each VLAN.

16, the method for claim 1 also is included in the step of inserting the failure cause indicating device in this alarm indication signal.

17, the method for claim 1 also comprises the step of the use in trigger protection path in response to the reception of this alarm indication signal.

18, the method for claim 1 if wherein client's level entity does not optionally suppress the enough information of this alarm according to this in the AIS that receives, just suppresses all alarms.

19, the method for claim 1 if being identified among the AIS that receives of client's level entity that wherein is isolated on the fault opposite side can obtain, so just optionally suppresses the known alarm of its sign.

20, a kind of network equipment of operating to provide connectivity fault notification in network comprises:

Can operate detect with this apparatus logic on the circuit of adjacent fault;

Can operate the logic that produces alarm indication signal in response to the detection of this fault; And

Can operate at least one port from this alarm indication signal at least one client's level entity that transmit.

21, equipment as claimed in claim 20 also comprises the logic that can operate the alarm indication signal that suppresses to be used for this srvice instance under the not ruined situation of srvice instance on certain grade on this grade.

22, equipment as claimed in claim 20 also comprises the logic that can operate the alarm indication signal that suppresses to be used for a srvice instance under the situation that this fault is repaired.

23, equipment as claimed in claim 20 also comprises the logic that can operate the alarm indication signal that suppresses to be used for a srvice instance in response to the management input.

24, equipment as claimed in claim 20 also comprises the logic that can operate the alarm indication signal that suppresses to be used for a srvice instance after a preset time section.

25, equipment as claimed in claim 20 also comprises the logic that can operate the alarm indication signal that suppresses to be used for a srvice instance behind the copy of the alarm indication signal that sends predetermined quantity.

26, equipment as claimed in claim 20 also comprises and can operate via transmitting the logic of this alarm indication signal with each port of the srvice instance associated nodes of this fault effects.

27, equipment as claimed in claim 20 also comprises and can operate the logic of transmitting this alarm indication signal via each port of this equipment.

28, equipment as claimed in claim 20 also comprises and can operate the logic of inserting point of failure indicator in this alarm indication signal.

29, equipment as claimed in claim 28, wherein point of failure indicator comprises MAC Address.

30, equipment as claimed in claim 28, wherein point of failure indicator comprises the fault resource identification.

31, equipment as claimed in claim 20 also comprises and can operate the logic of inserting the failure cause indicating device in this alarm indication signal.

32, equipment as claimed in claim 20 also comprises the logic that can operate the use in trigger protection path in response to the reception of this alarm indication signal.

33, equipment as claimed in claim 20 wherein is that each affected VLAN produces different multicast alarm indication signals.

34, equipment as claimed in claim 20 wherein is that each affected VLAN produces different clean culture alarm indication signals.

35, equipment as claimed in claim 20 if wherein client's level entity does not optionally suppress the enough information of this alarm according to this in the AIS that receives, just suppresses all alarms.

36, equipment as claimed in claim 20 if being identified among the AIS that receives of client's level entity that wherein is isolated on the fault opposite side can obtain, so just optionally suppresses the known alarm of its sign.