CN108462635A - A kind of communication network path in more place networks and status information - Google Patents

Abstract

The invention discloses the method and apparatus that communication network path and status information notice are realized in more place networks.Example network system includes (L2) device of layer two and layer three (L3) device.L2 devices include control unit, it is configured to determine that the preferred network path from the first L2 networks to intermediate L3 networks, wherein, L2 devices reside in the first L2 networks, and L3 devices, which reside in, couples in the intermediate L3 networks of the 2nd L2 networks with the 2nd L2 devices the first L2 networks to.Control unit includes management endpoint (MEP) module.The MEP modules execute operation, manage and safeguard (OAM) agreement to monitor the first L2 networks and be exported L2 frames to L3 devices according to OAM agreements, with notify L3 devices its in preferred network path.The MEP modules of L3 devices execute OAM agreements, will indicate that the L2 frames of L3 network states are exported to L2 devices.

Description

A kind of communication network path in more place networks and status information

Technical field

The present invention relates to computer network, more particularly, in computer network Path selection and fault detect.

Background technology

Computer network is the set of the computing device for the interconnection for exchanging data and shared resource.Computing device can by one or Multilink interconnects.Term " link " may include such as copper wire, same commonly used in referring to the connection on network between two devices The physical medium of any one of shaft cable or many different optical fiber cables, or be wirelessly connected.In general, in densely inhabited district, Computer network includes the link to be circular layout.When being formed as ring, network is known as " loop network ".Densely populated The loop network in area, execution level two (L2) ethernet communication protocol is properly termed as " metro ethernet network ".

In typical configuration, Metro Ethernet includes the metropolitan area terminal unit (MTU) of multiple interconnection, (is claimed to computing device For customer users device) access of the offer for Metro Ethernet.Computing device is coupled to MTU to obtain for Metro Ethernet Access, and then be coupled to Metro Ethernet other computing devices interconnect.One or more layers three (L3) provider edge (PE) router can couple Metro Ethernet to public network (such as internet) or other dedicated networks.Via the roads PE By device, computing device can access public network or dedicated network using Metro Ethernet.MTU conducts in Metro Ethernet The operation of two (L2) device of layer and communicated with the associated L2 of network equipment since MTU is forwarded (for example, Ethernet packet, also referred to as with Too net frame), therefore it usually knows the L2 network address (for example, the address media access control (MAC)) of various network equipments.One Denier knows that the mac address information known just is stored in the more effective interchanger that L2 is communicated in Ethernet by MTU.When MTU is received When to the additional packets for being directed toward network equipment with the MAC Address known, the mac address information of MTU inquiry storages is simultaneously based on The data packet is transferred to network equipment by the information of storage.

Operations, Administration and Maintenance (OAM) be often referred to process, activity, tool, standard and other be related to Operations, Administration and Maintenance (example Such as, fault diagnosis) computer network technology.The OAM technologies of combination may be constructed OAM agreements.OAM agreements (it is such as electrical and Connecting fault management (CFM) described in Electronic Engineering Association (IEEE) 802.1ag standards) may include a variety of actives and examine Disconnected fault locating program.For example, can be initiatively with set rate by continuity check according to the network equipment of CFM operations (CC) message is transmitted in identical other devices safeguarded in joint, and receives CC message from the device.Maintenance combine be with It is set to the logic groups of the device in the network for the integrality for verifying single Service Instance.For example, Service Instance can indicate to provide A part for quotient's network (particular customer can access the network to inquire the state for being sent to the service of the client).CC message to Safeguard that other network equipments in joint provide connectivity verification.

The link and/or device of network may be out of order due to any one of many reasons.When the link or dress of network It sets when being out of order, as a result usually for the degradation or loss of the service of particular customer, this is undesirable.Therefore, network pipe Reason person wishes the duration of fault restriction.It is a kind of mitigate pe router failure influence conventional method be utilize " more places " frame Structure is in the architecture coupled Metro Ethernet with public network using the pe router of more than two redundancies.In operation, The MTU for being coupled to more than two redundancy pe routers selects a pe router as preferred pe router, and excellent by this Data packet is sent to public network by the pe router of choosing.However, even if being only preferred pe router there are one pe router, The each pe router for being connected to MTU also usually handles the data packet for being transferred to and from MTU and reserves resource.When MTU is more In the case of place, it may be deposited in connecting the public network of preferred pe router and the network equipment outside Metro Ethernet In network error.Traditionally, the mac address information of storage must MTU by network packet not include network error it is different (age out) is failed before being transmitted on network path.That is, MTU continuation is transmitted on the network path including network error Packet, until the mac address information of storage is eliminated, this leads to packet loss.In order to make the quantity of loss or discarding packet It minimizes, pe router can pass through the link of " waving " (flap) between MTU and pe router or disconnection (bring down, drop It is low) link and keep the link between pe router and MTU unavailable.Pe router can be by quickly continuously issuing to MTU A series of message (between instruction path is available and instruction path is unavailable alternately) come " waving " between MTU and pe router Link so that MTU refresh (flush) storage mac address information.Using any one of these technologies, pass on the link The data packet broadcast may lose, and client sends or received data packet may be adversely affected.In addition, transporting on the same link Row may be waved due to disconnecting link or link without the service that is influenced by network error and is interrupted.

Invention content

In general, the technology of network event can be notified between (L2) network of layer two and layer three (L3) network by describing, The operation of network equipment can be improved and make to interrupt caused by network error and minimized.The technology may be in more place Metro Ethernets In be particularly useful.For example, the technology can be applied to following situations：The L2 client access devices (for example, MTU) of Metro Ethernet are right It is more places in coupling Metro Ethernet to more than two L3PE routers of another network (such as public network).At one In example, the OAM agreements executed on MTU and pe router can be used to apply the technology, wherein in each MTU and PE The OAM agreements executed on router are to other MTU and pe router sending cycle message, to detect network error and convey excellent The path of choosing.According to the techniques described herein, MTU and pe router can use the OAM agreements extended, the agreement to be applied not only to Continuity check and traditional network operation are additionally operable to pellucidly be embedded in the letter that the triggering for the MAC Address that related MTU is known refreshes Breath.

As another example, the more place MTU for L3 networks being coupled to by multiple pe routers can utilize periodical OAM message, The message is applied not only to connectivity inspection and traditional network operation, is additionally operable to which currently selects to pe router notice MTU Pe router is provided to the connection of external network (such as public network or dedicated network) as preferred pe router.This Sample, in response to causing to select changed network event, for example, coupling change notice to the not preferred path P E of MTU Router, and its automatic releasing network resource in response.

In another exemplary operation, coupling Metro Ethernet to the pe router of L3 networks can use Routing Protocol (all Such as Border Gateway Protocol (BGP) or label distribution protocol (LDP)) detect the network error in L3 networks.By by the information Pellucidly insertion is additionally useful in the periodic message of OAM agreements of connectivity inspection, and pe router can pass network state It send to the MTU of Metro Ethernet.Then, MTU can make Path selection decision based on the network state information received.For example, MTU can change preferred network path, to which the second pe router for being again coupled to MTU is included in preferred network now In path, and the first pe router in preferred network path was no longer in preferred network path originally.MTU can be via The network path of change is preferentially alternately sent to each pe router by periodic message.

In another exemplary operation, pe router instructs MTU refreshings leading to PE routings using the periodic message of OAM agreements One or more MAC Address that the chain road of device is known.For example, in response to detecting the network error in public network, or ring Ying Yu knows that pe router is no longer in preferred network path, and pe router can order MTU to refresh MAC Address.In this way, PE Router can avoid waving link, be also prevented from the service of operation (without being influenced by network error) on the same link The loss of correlative flow.In the above example, which can be continuity check (CC) message, and may include Type one Length Value (TLV) of the additional network information as CC message.

In an example, a kind of method includes：Operation is executed on first network device, manages and safeguard (OAM) agreement To monitor first layer two (L2) network, wherein first network device is run in the first L2 networks.This method further comprises really Determine to lead to the network path of the second network equipment via third network equipment to be preferred network path, wherein the second network equipment It is run in the 2nd L2 networks, wherein the 2nd L2 networks are different from the first L2 networks, and wherein, the first L2 networks and second L2 networks are coupled by layer three (L3) network, and are filled to third network using the OAM agreements executed on first network device It sets and gives out information, wherein the message informing third network equipment third network equipment is in preferred network path, Yi Jiqi In, third network equipment couples L3 networks with the first L2 networks.

In another example, a kind of network equipment, including：Multiple physical network interfaces, for sending and receiving packet；And control Unit is configured to determine that the preferred network path for leading to the second network equipment.Control unit includes management endpoint (MEP) mould Block, the module are configured as executing operation, manage and safeguard (OAM) agreement, to monitor first layer two (L2) network, use OAM agreements generate message, and send a message to third network equipment via one of multiple physical network interfaces, wherein this disappears It ceases and indicates third network equipment in the preferred network path for leading to the second network equipment to third network equipment, wherein network Device is run in the first L2 networks, wherein the second network equipment is run in the 2nd L2 networks, wherein the first L2 networks and 2nd L2 networks are different L2 networks, wherein layer three (L3) network couples the first L2 networks and the 2nd L2 networks, and its In, third network equipment couples the first L2 networks to L3 networks.

In another example, a kind of system, including：First network device and the second network equipment.First network device includes the A physical network interface more than one and the first control unit.First control unit includes first management endpoint (MEP) module, with And the address media access control (MAC) repository, which, which is configured as being stored in, is coupled to multiple physical network interfaces The MAC Address known on multilink.Second network equipment includes that more than second a physical network interfaces and the second control are single Member.Second control unit includes the 2nd MEP modules and routing engine, wherein routing engine is configured as executing one or more A Routing Protocol.First control unit is configured to determine that the preferred network path for leading to third network equipment.First MEP modules It is configured as executing operation, manages and safeguard (OAM) agreement, to monitor first layer two (L2) network, generated using OAM agreements Message, and the second network equipment is sent a message to via one of multiple physical network interfaces, wherein the message is to the second network Device indicates the second network equipment in the preferred network path for leading to third network equipment.Third network equipment is in the 2nd L2 nets It is run in network, wherein the 2nd L2 networks are different from the first L2 networks, wherein couple the first L2 networks using layer three (L3) network With the 2nd L2 networks.2nd MEP modules are configured as executing OAM agreements to monitor the first L2 networks, and analyze from first network The first message that device receives, to determine the second network equipment whether in the preferred path for leading to third network equipment.Second Whether control unit is configured as, available to the distribution of the second network equipment based on the second network equipment in preferred network path Resource.

In another example, it is encoded with WEEE ＆ RoHS in Junction for Computer readable storage medium storing program for executing, these instructions are for so that one or more A programmable processor executes following operation：Using operation, management and safeguard that (OAM) agreement is determined via third network equipment Network path from first network device to the second network equipment is preferred network path, wherein first network device is first Operation in L2 networks, wherein third network equipment is run in the 2nd L2 networks, wherein the 2nd L2 networks are different from the first L2 Network, and wherein, L2 networks are coupled via layer three (L3) network, and instruction third network dress is issued to the second network equipment Set the message in preferred network path.

Specific implementation mode

The system includes being coupled to network via link 19A and 19B and provider edge (" PE ") router 14A and 14B Exemplary more place Metro Ethernets (" ME ") network 12A.Network is further coupled to the 2nd ME networks via pe router 14C 12B.Pe router 14A-14C (being referred to as " pe router 14 ") helps to be connected to ME networks 12A and 12B (general designation " ME networks 12 ") the access to content between various network equipments (such as customer set up (" CD ") 18A and 18B (being referred to as " CD18 ")).Each CD 18 may each be personal computer, laptop computer, mobile phone, the networking telephone, TV set-top box, video-game system System, point of sale device, personal digital assistant, intermediate network devices, network request people or can be with 12 interface of ME networks and communication Other kinds of device.In addition, each CD18 may each be gateway, router, interchanger or for coupling customer network To other devices of ME networks 12.

Network can be middle layer three (L3) network, use one or more agreement (such as Internet protocol/biographies based on packet Transport control protocol discusses (IP/TCP)) it can realize content transmission between network equipment.In this respect, network can be supported via logical Often it is known as the data transmission for the discrete data unit " wrapped ".Therefore, network is properly termed as " being based on packet " or " packet switch " network. ME networks 12 can support the data transmission via layer two (L2) frame (for example, ethernet frame).Therefore, each ME networks 12 Referred to as Ethernet or more commonly referred to as L2 networks.Although be described as in the disclosure transmission, transmission or support packet (for example, Network 10) and frame (for example, ME networks 12), but network and ME networks 12 can be transmitted according to any other protocol definition Any other discrete data unit is (such as by the unit of asynchronous transfer mode (ATM) protocol definition, or by User Datagram Protocol (UDP) datagram defined) data.

Network can indicate the public network that one or more service providers possess and run, so that multiple edge networks are (all Such as ME networks 12) interconnection.Therefore, network is properly termed as service provider (SP) network herein, or alternatively, referred to as " core network ", this is because network is used as the core of interconnection edge network (such as ME networks 12).Routing in network 10 and Packet forwarding can according to L3 network routing protocols (such as Border Gateway Protocol (BGP), or sometimes referred to as 2.5 agreement of layer mark Label distributorship agreement (LDP)) it is operated.ME networks 12 can use L2 procotols (such as Ethernet) to run.It is related subsequent The reference of " layer " with number can refer to the certain layer of open system interconnection (OSI) reference model.

Network may include the pe router at multiple edges for residing at service provider network.Although herein with respect to specific Network equipment (that is, router) be discussed, but each pe router 14 can indicate and network (such as ME networks One of 12) interface is to route any L3 network equipments for the network flow being directed toward or from network 10 and ME networks 12.For example, In some cases, each pe router 14 can indicate one or more routers, gateway, fire wall, intrusion detection/pre- Prevent (IDP) device or contributes to any other type of the data transmission in network and between network and ME networks 12 The L3 network equipments.

In example, ME networks 12A includes metropolitan area terminal unit (MTU) 16A-16F (being referred to as " MTU 16 "), and ME networks 12B includes MTU 17A-17D (are referred to as " MTU 17 ").It is similar to pe router 14, although herein with respect to specific network equipment (example Such as, interchanger) MTU 16,17 is discussed, but it is each can indicate with network (such as ME networks 12) interface with Exchange or forward any L2 network equipments for the network flow being directed toward or from network.For example, in some cases, each MTU 16,17 can indicate one or more interchangers, hub, fire wall, IDP devices or contribute in ME networks 12 And the L2 network equipments of any other type of the data transmission between ME networks 12 and pe router 14.

For the ease of being safeguarded to the interconnection of network 10 and ME networks 12, one or more pe routers 14 and one or more MTU 16,17 can implement Operations, Administration and Maintenance (OAM) technology, the connectivity described in such as IEEE 802.1ag standards Fault management (CFM).CFM usually can be to being transferred to and from the data cell (example of particular network user (for example, ME networks 12) Such as, frame or packet) it is found and is verified by network equipment and network paths traversed.In general, CFM be related to L2 service it is (all Such as Virtual Private LAN Service (VPLS)) and L2 networks (such as Ethernet, or be LAN (LAN)) in fault management.Though It is so described herein in regard to L2 networks and service and CFM, but the technology can be utilized in order to be performed simultaneously maintenance Session and the operational management of network and about OSI Reference Model other layers provide service.

CFM usually provides one group of agreement, and fault management is executed by the agreement.An agreement in the CFM protocol groups (is known as " continuity check agreement ") it is related to the periodic transfer of information, with the continuity between two determination, verification or inspection endpoints.It can With in entitled " the IEEE Standard forLocal and that the date of LAN/MAN standard committees is on December 17th, 2007 metropolitan area networks-Virtual Bridged Local AreaNetworks-Amendment 5： Found in Institute of Electrical and Electric Engineers (IEEE) draft standard of Connectivity Fault Management " about The more information of 802.1ag standards and CFM protocol groups (including continuity check agreement), entire contents are hereby expressly incorporated by ginseng It examines.

According to CFM, one or more administrators of customer network 14 or user can configure each MTU 16 and pe router Maintenance association endpoint (MEP) in 14A, 14B.Each MTU 16 and pe router 14A, 14B can be configured with one or more MEP, a MEP is for each Service Instance in multiple Service Instances.Each MEP can indicate the CFM actively managed Entity generates and receives continuity check (CC) Message Protocol Data Unit (PDU) and any response of tracking.In configuration MEP When, administrator can make MEP associated with particular service instance, to verify the integrality of single Service Instance.Each service is real Example can correspond to specific client and/or specific virtual LAN (VLAN).

Each MEP can periodically send continuity check (CC) message, announce the Service Instance of the MEP of transmission.One In a example, CC message is two frame of layer (for example, ethernet frame), more specifically, being Ethernet OAM frame.MEP can be by the message It multicasts to including each MEP in example containing same services.Therefore, MEP knows that it is expected to be exchanged therewith (for example, sending And receive) one or more MEP of CC message.Then, MEP can continue the friendship of CC message according to the configuration of each MEP It changes.MEP can execute continuity check agreement, with according to being configured or in some cases (for example, after the initial configuration In the case of there is no any administrator or other users to supervise) period of setting exchanges these CC message automatically.

According to the technology of the disclosure, ME networks 12A (it is with the MTU 16 for being configured with one or more MEP) can be with passing through To the physical connection of the redundancy of network 10, which is referred to as " more places " multiple pe routers 14.Shown in the example as shown in, ME networks 12A is more places for network 10 by MTU 16A, 16B and pe router 14A, 14B.In more places, MTU 16 is selected One of pe router 14A, 14B are selected, is in the preferred network path as leading to network 10.Pe router 14A, 14B In router in preferred network path via the MTU in MTU 16A, 16B in preferred network path and in ME networks Transmitted traffic to and fro between 12A and network 10.Another router being not in pe router 14A, 14B in preferred path It is Backup Data transponder, it can be the network failure of another transmitted traffic in interfering router 14A, 14B the case where Under, for the flow from ME networks 12A to ME network 12A transmitted traffics and transmission.

MTU 16 can select preferred network path in various ways, and various ways include, for example, being randomly or based on pipe Network status of the configuration parameter of reason person's input in response to such as network error.For example, if MTU 16A selections include PE routings The network path of device 14A is as the preferred network path for reaching network 10, then according to techniques described herein, MTU 16A can To notify pe router 14A in preferred network path to pe router 14A.In one embodiment, MTU 16A's is corresponding MEP generations are extended to the CC message including additional type-length-value (TLV) and send this information to pe router 14A, As the part for executing continuity check agreement.The additional TLV is reached to pe router 14A notices pe router 14A In the preferred network path of more place L3 networks.Since pe router 14A is in preferred network path, so pe router 14B is not In preferred network path.In one embodiment, the corresponding MEP of MTU 16A generates CC message and sends it to the roads PE By device 14B, but the message does not include the TLV to pe router 14A notices pe router 14A in preferred network path.

In another example, MTU 16A corresponding MEP generate CC information, the CC extension of message be include additional TLV, By (for example) by the value of the value field in TLV be set as 0 or 1 come to each reception pe router notify pe router whether In preferred network path.Value 0 can show pe router not in preferred path to pe router, and value 1 can be to pe router Show pe router in preferred path.In this way, notifying each router whether excellent to each pe router 14A and 14B It selects in network path, and each router can adjust accordingly the distribution of its available resources.By extending CC message to wrap Include additional TLV, in addition to traditional continuity check, L2 devices can also using CC message and with L3 devices (its provide pair In the connection of L3 networks) carry out transparent communication, wherein and L3 devices are on the preferred path for leading to L3 networks.

For example, pe router 14A and 14B use procotol (such as Border Gateway Protocol (BGP) and label distribution protocol (LDP)) it is communicated with pe router 14C via network 10.If pe router 14A is used (for example) based on multiprotocol label The Programmable detection of (MPLS) is exchanged to about the connection sex chromosome mosaicism in network 10, or if pe router 14A via procotol (for example, BGP or LDP) receives the notice of network problem, then pe router 14A can be used as the clothes for including MTU 16A The MEP of a part for pragmatic example operates the TLV of generated CC message, to MTU 16A notice connection sex chromosome mosaicisms.That is, layer three Device (for example, pe router 14A) fortune into two network of layer (for example, ME network 12A) using L2 agreements (for example, CFM agreements) Capable layer two devices (for example, MTU 16A) notify the mistake in L3 networks (for example, network 10).Once receiving CC message Notice, MTU 16A can change the preferred network path of certain or all flows for being forwarded by pe router 14A. If MTU 16A change its preferred path, MTU 16A can be notified via above-mentioned CC message to pe router 14A and 14B The preferred path of change.

Packet is exchanged in ME networks 12A and using pe router 14A, 14B due to MTU 16A, MTU 16A are by MTU 16A, which is connected on link 19A, 19B of pe router 14A, 14B, knows remote mac address (for example, MAC Address of CD18B). For example, if initial preferred network path includes link 19A and pe router 14A, and pe router 14A detects network 10 In mistake, then with the MEP that is executed on the associated pe router 14A of the particular service instance of the erroneous effects in by network 10 Generate CC message simultaneously send it to MTU 16A, according to techniques described herein, the CC extension of message be include for MTU 16A notice network errors simultaneously indicate that MTU 16A will refresh the TLV for all MAC Address known on link 19A.Then, MTU 16A can select such as new preferred network path including link 19B and pe router 14B.Once selecting newly excellent Network path, MTU 16A is selected just to know the remote mac address on link 19B again.In this way, three device of layer in three network of layer With layer two devices (the one or more Service Instances executed on layer two devices by the network error in three network of layer shadow Ring) it is communicated, and make the update of layer two devices for the network route information of impacted Service Instance, without influencing in layer Other Service Instances of packet are exchanged in same physical link between three device of two devices and layer.

Implement the block diagram of the exemplary MTU 20 of technology described in the disclosure.In order to illustrate, below can exemplary ME MTU 20 is described, and it can indicate any one MTU under the background of network 12A

16、17.MTU 20 includes receiving control packet and data packet simultaneously via inbound 23A-23N (being referred to as " inbound 23 ") Control packet and the network interface card 22A-22N (systems of data packet are sent via outbound link 24A-24N (being referred to as " outbound link 24 ") Claim " IFC 22 ").Letter " N " is for indicating any number of device herein.IFC 22 is usually via multiple interface ports (not shown) is coupled to link 23,24.

Control unit 21 may include execute store in computer readable storage medium (in be not shown) software instruction (such as Those are used for defining the software instruction of software or computer program) one or more processors (in be not shown).Computer can The example for reading storage medium includes storage device (for example, disc driver or CD-ROM drive) or memory (for example, flash memory, random Access memory or RAM) or store instruction so that programmable processor executes any other class of techniques described herein The volatile memory or nonvolatile memory of type.Optionally, or in addition, control unit 21 may include specialized hardware, example Such as one or more integrated circuits, one or more application-specific ICs (ASIC), one or more specific use processing Device (ASSP), one or more field programmable gate arrays (FPGA), or the examples detailed above of one or more specialized hardwares Any combinations, to execute techniques described herein.

Control unit 21 is that MEP modules 26, forwarding engine 28 and administrator interfaces (" ADMIN INTERFACE ") 30 provide operation Environment.Control unit 21 also provide for the repository (" MAC DATA ") 32 of MAC Address, forwarding information storehouse (" FIB ") 34, with And configuration data (" CONFIG DATA ") 36.MEP modules 26, which provide, allows MTU 20 (such as according to 802.1ag standards) conduct Manage the function of endpoint operation.More generally useful, MEP modules 26 are the one or more OAM agreements executed in control unit 21 Example.

In general, forwarding engine 28 checks the packet received via an inbound 23 and IFC 22, (for example) to be based on including mesh The header information of packet of way address determine the destination of packet.Forwarding engine 28 is held based on the header information of packet in FIB34 Row inquiry, to determine an IFC 22 for being sent to packet and outbound link 24.Since MTU 20 sends and receives packet, control Unit 21 processed knows the MAC Address on inbound 23, and MAC Address is stored in MAC data 32.MAC data 32, FIB 34 and configuration data 36 can be stored according to individual data structure or together according to a data structure, and can be according to One or more tables, database, chained list, Ji Shu (radix tree) or other suitable data structures form and store.

According to the technology of the disclosure, operator is interacted with administrator interfaces 30 to instruct MEP modules 26 to execute CFM operations, To find and manage the failure in network, other network equipments into Service Instance issue CC message, and are filled to other networks Set the network route information that notice includes preferred path information.For example, administrator can input order to check and change configuration Data 36 are automatically generated with specified time interval (for example, once per second or once every minute) such as institute in 802.1ag standards The CC message of definition.The current-configuration of MTU 20 is included in configuration data 36.

MEP modules 26 can manage the MEP work(for MTU 20 in one or more Service Instances using it as MEP role Energy.MEP modules 26, which examine the CC message received and generate CC according to configuration data 36 (that is, with configurable time interval), to disappear Breath, and CC message is sent to and the associated specific MTU of particular service instance and pe router.For example, MEP modules 26 can To examine the CC message received and determine that the CC message received includes and the network state notice pair from pe router 14A The TLV answered.Network state TLV instruction for existing particular network state in the network path of packet, the packet be used for and receive To CC message in the corresponding Service Instance of particular service instance that identifies it is associated.Network state TLV can indicate network segment It is not forwarded, network segment is in standby, or there are telecommunication network segment faults.For example, MTU 20 can be from pe router 14A receives CC message, the message include the link for showing between pe router 14B and pe router 14C do not forward it is network-like State TLV.Show that the CC of the network error in core network (network 10 in for example) disappears in response to what is received from pe router Breath, MTU 20 can change preferred network path and transmit packet to bypass network error.

No matter arbitrarily in response to knowing specific network state or due to certain other reasons, if MTU 20 changes preferably Network path, then MEP modules 26 generate and send CC message, the Information expansion be include to receive pe router notice receive PE Router whether the TLV in newer preferred network path.If pe router is not in initial preferred network path, but not In newer preferred network path, then pe router can previously be handled by (for example) discharging along initial network path The resource that the packet (it is transmitted along newer preferred network path now) of transmission is reserved.

In another example, MTU 20 can receive CC message, command M TU from pe router (for example, pe router 14A) 20 refresh one group of MAC Address being stored in MAC data 32.In this example, the inspection of MEP modules 26 is received from pe router CC message simultaneously determines that the CC message includes the one or more MAC Address for indicating MTU 20 and refreshing from MAC data 32 TLV.For example, MEP modules 26 determine that TLV includes value field, which is arranged to correspond to particular virtual local area network (VLAN) identifier, specific I-SID (Service Instance VLAN ID), particular mac address value or be arranged to MTU 20 refer to Show that MTU 20 will refresh the value of all MAC Address known.After specifying which MAC Address in determining CC message TLV, control Unit 21 processed refreshes specified MAC Address from MAC data 32.

It is the block diagram for the exemplary pe router 40 for showing the technology that can implement the disclosure.In order to illustrate below may be used With exemplary network 10 and ME networks 12 background under pe router 40 is described, and it can indicate any one road PE By device 14.Pe router 40 includes receiving control packet and data packet via inbound 47A-47N (being referred to as " inbound 47 ") And the network interface card 46A-46N of control packet and data packet is sent via outbound link 48A-48N (being referred to as " outbound link 48 ") (being referred to as " IFC 46 ").In general, IFC 46 is coupled to link 47,48 via multiple interface ports.

Control unit 41 may include execute store in computer readable storage medium (in be not shown) software instruction (such as Those are used for defining the software instruction of software or computer program) one or more processors (in be not shown).Computer can The example for reading storage medium includes storage device (for example, disc driver or CD-ROM drive) or memory (for example, flash memory, random Access memory or RAM) or store instruction so that programmable processor executes any other class of techniques described herein The volatile memory or nonvolatile memory of type.Optionally, or in addition, control unit 41 may include specialized hardware, example Such as one or more integrated circuits, one or more application-specific ICs (ASIC), one or more specific use processing Device (ASSP), one or more field programmable gate arrays (FPGA), or the examples detailed above of one or more specialized hardwares Any combinations, to execute techniques described herein.

Control unit 41 can logically be divided into management plane 42, routing plane 43 and Forwarding plane 44.In this example, turn Hair plane 44 may include any combinations of hardware and/or software, and the forwarding capability for executing pe router 40 (is such as wrapped and tested Card, path query, transmission).In some instances, Forwarding plane 44 is completely or partially distributed to IFC46, to input Packet is performed in parallel forwarding capability.The forwarding information of FIB 52 is by network destination and specific next-hop and corresponding interface end Mouth is associated.Forwarding plane 44 further includes the forwarding engine 50 that packet is handled according to FIB 52.In general, when pe router 40 When receiving packet via an IFC 46 (for example, IFC 46A), IFC 46A will include IFC 46A receive packet on which port Instruction packet be sent to forwarding engine 50.Forward the header letter of packet of the engine 50 (for example) based on the IP address including destination It ceases to check packet to determine the destination of packet.In an example, forwarding engine 50 checks the forwarding letter being stored in FIB 52 It ceases and the header information based on packet executes inquiry.

Management plane 42 includes administrator interfaces (" ADMIN INTERFACE ") 54 and MEP modules 56.MEP modules 56 indicate root According to the illustrative examples of the management endpoint of 802.1ag standards, or more generally useful, the OAM executed in control unit 41 associations are indicated The example of view.That is, MEP modules 56 generate CC message and check the MEP executed out of other network equipments (for example, from MTU 16A) the CC message received.

According to the technology of the disclosure, operator is interacted with administrator interfaces 54 to instruct MEP modules 56 to execute CFM operations, To find and manage the failure in network, other network equipments into Service Instance issue CC message, and are filled to other networks Set the network path message that notice includes preferred path information.For example, administrator can input order to check and change configuration Data 62 automatically generate CC message with specified time (for example, every five seconds for example once or once every minute).Pe router 14A's works as Preceding configuration is included in configuration data 62.

MEP modules 56 can be managed as MEP role for pe router 40 using it in one or more Service Instances MEP functions.MEP modules 56 check the CC message received, and raw according to configuration data 62 (that is, with configurable time interval) It is sent at CC message and by CC message and the associated specific MTU of particular service instance and pe router.For example, routing is drawn The network state of potential network error in three network of marker can be known by holding up 58 so that MEP modules 56, which generate extension, finger The particular service instance for having shown the CC message of the additional TLV of network state, and having sent this information to and being influenced by network state An associated specific MTU and pe router.In response to the network state known, MEP modules 56 can be configured to Generate and send CC message, which has additional TLV, the TLV instruct receiving layer two devices (for example, MTU 16A) from Refresh specified one group of MAC Address in TLV in one group of MAC Address known being stored in MTU 16A.MEP modules 56 Can generate be extended to including indicate network state TLV and instruct MTU with refresh specified MAC Address group TLV it is single CC message or MEP modules can generate and send two individual CC message, and one is extended to including network error TLV, the Two are extended to including mac refresh TLV.MEP modules 56 can receive CC message, the CC message from MTU (for example, MTU 16A) It is extended to the TLV for including instruction pe router 40 in preferred network path.Once it is determined that the CC message received includes preferred road Diameter TLV just configures needed for the reserved associated packet of Service Instance for being identified in processing and CC message pe router 40 to Resource.After reserved required resource, MEP modules 56 can receive the CC message corresponding to same services example, but it is not Including preferred path TLV.When pe router 40 continues to CC message of the instruction pe router 40 in preferred network path, Pe router 40 is configured as continuing the previously reserved Internet resources of distribution to handle and the associated packet of Service Instance.Once receiving To the CC message of no preferred path TLV, pe router 40 be configured to (for example) by discharge previously reserved resource come Adjust how it distributes resource, with processing and other associated packets of other Service Instances.

It includes routing engine 58 and routing information base (" RIB ") 64 to route plane 43.Routing engine 58 may include hardware and soft Part it is any appropriately combined, execute the routing function of pe router 14A, such as calculate packet routing and execute Routing Protocol 60 with Safeguard routing table.Routing engine 58 safeguards the routing iinformation in RIB 64, describes the topology of network, specifically, passes through network Routing.For example, RIB 64 may include describe network in various routings routing data, and instruction for every routing The corresponding next-hop data of appropriate apparatus adjacent in network.

Routing plane 43 is to execute Routing Protocol 60 to provide operating environment.Routing Protocol 60 is typically set up and other route devices Peer-to-peer communications session, to exchange the routing iinformation being stored in RIB 64, to know the topological structure of network, more specifically, Know the routing of other network equipments (for example, CD 18B) in leading to network.Routing Protocol 60 may include external routes association It discusses (such as external BGP (eBGP)), with the routers exchange with autonomous system (autonomous system) or other routed domains Routing iinformation.In addition, or optionally, Routing Protocol 60 may include interior routing protocol (such as internal bgp (iBGP), routing Information protocol (RIP), Interior Gateway Routing Protocol (IGRP), ospf (OSPF) or intermediate system are in Between system (IS-IS)), the routing to learn identical routed domain or as the destination in the autonomous system of pe router 40.

Routing engine 58 is further generated destination information (such as IP address prefix) and specific forwarding next-hop and IFC 46 The associated forwarding information of corresponding interface port, and to Forwarding plane 44 provide forwarding information.Based on being stored in RIB 64 In information and the configuration information that is stored in configuration data 62 determine forwarding information.The configuration information of configuration data 62 includes Such as safeguard that domain information, maintenance association information and CC message generate the information at interval.Forwarding information is stored in FIB 52.It can be with According to one or more tables, database, chained list, Ji Shu or other suitable data structure form storage RIB64, configuration datas 62 and FIB 52.

The exemplary continuous of the disclosure examines (CC) Message Protocol Data Unit (PDU) 70.CC message PDU 70 includes public Connectivity fault management (CFM) header 72, maintenance association endpoint identifier (" MAEP ID ") 76, is safeguarded and is closed sequence-number field 74 Join ID (" MAID ") 78, measured information 80, type-length-value (" TLV ") field 82 and TLV tails field 84.It is public CFM headers 72 include specifying to safeguard domain grade, the field of version, specify the operation code of the format and meaning of PDU rest parts, packet Include the label of CC message intervals, the first TLV offsets and TLV tails.Measured information 80 include CC message PDU the 59th to 74th eight bit byte, the Y-series authorized by International Telecommunication Union-telecommunications (ITU-T)：GLOBALINFORMATION INFRASTRUCTURE, INTERNET PROTOCOLASPECTS AND NEXT-GENERATION NETWORKS, OAM Y.1731, functionsand mechanisms for Ethernet based networks are defined for 2 months 2008, complete Portion's content is hereby expressly incorporated by reference.TLV fields 82 are the optional elements of CC message PDU 70.It is further described about A and B TLV fields 82.

A and B is the example format that may be embodied in the TLV in CC message PDU (for example, CC message PDU 70).The TLV of A 90 be the example of the format defined by the 802.1ag standards of the TLV with the type included in 802.1ag standards.TLV 90 Including type field 92, length field 94 and value field 96.Type field 92 is TLV indispensable elements, identifies the class of TLV Type, and can be an eight octet field.For example, if setting type field 92 to value 1, TLV is identified as to send Hold ID TLV.As another example, if setting type field 92 to value 0, TLV is identified as TLV tails.When by class type-word When section 92 is set as value 0, length field 94 and value field 96 are not present in TLV.If type field 92 is set as non-zero Then there is length field 94 and indicate the size of value field 96 according to eight bit byte in value.Value field 96 be include memory length The optional element of the quantity of eight bit byte in field 94 needed for specified information.If setting length field 94 to value 0, Value field 96 is then not present.

According to the disclosure, CC messaging protocols can be extended to including one or more preferred network path TLV, connection status TLV And mac refresh TLV.For each of these new TLV, can be defined as identifying TLV corresponding to the value of type field 92 For preferred network path TLV, connection status TLV or mac refresh TLV.According to the disclosure, the MTU 16,17 as MEP operations It is configurable to generate with pe router 14 and sends or receive and handle and meet lattice shown in CC message PDU 70 and TLV 90 The CC message of formula, with other network equipments notice preferred network routing information, the connection state information into MAC, and/or instruction Mac refresh.

As an example, more place PE of such as PE 14A are configured as, once it is received from MTU with preferred network path Whether the CC message of TLV just checks the CC message received and determines PE 14A in preferred network path.In one embodiment In, pe router 14 can determine pe router 14A based on the value field 96 of the preferred network path TLV of the CC message of reception Whether in preferred network path.In another embodiment, pe router 14 can be based simply on the preferred net in CC message The presence or absence of network path TLV determines if on preferred network path.

In an example, if the network path including pe router 14A is identified as preferred network path by MTU 16A, The generation of MEP modules 26 of MTU 16A includes the CC message of CC message PDU (for example, CC message PDU 70) comprising TLV 90, Wherein type field 92 is arranged to for TLV to be identified as the value of preferred network path TLV.For example, because only needing one eight Byte is to include preferred network routing information, so the type field 92 that TLV is identified as to preferred network path TLV can be value 9, length field 94 could be provided as value 1, and set value field 96 to value 1, wherein value 1 indicates PE to pe router 14A Router 14A is included in preferred network path.Continue the example, the MEP modules 26 of MTU 16A can generate the 2nd CC message To be sent to pe router 14B.2nd CC message includes TLV, has the value for being set as that mark TLV is preferred network path The type field 92 of (for example, 9), is set as the length field 94 of value 1, and is set as the value field 96 of value 0, wherein value 0 to Pe router 14B instructions pe router 14B is not included in preferred network path.

In another example, MTU 16A identify preferred network path and include pe router 14A but do not include pe router 14B. In the example, the generation of MEP modules 26 includes the CC message of preferred network path TLV, to be sent to pe router 14A.It is preferred that net Network path TLV includes：Type field 92 is arranged to identify the value that TLV is preferred path TLV；And length field 94, It is arranged to value 0, but does not include value field 96.In this example, it does not include preferred network path TLV's that MEP modules 26, which generate, CC message is to be sent to pe router 14B.After receiving the CC message including preferred network path TLV, pe router 14A Resource needed for reservation process packet associated with the Service Instance specified in CC message.On the contrary, pe router 14B is being received After the CC message including preferred network path TLV, any previously reserved resource of release.

In other aspects, the pe router 14 as MEP operations can be generated with connection status TLV and/or mac refresh TLV CC message.Example T LV 90 corresponding to connection status TLV includes：Type field 92 is arranged to identify TLV to be connection The value (for example, value 10) of state TLV；Length field 94 is arranged to the length (example of the content of value field 96 according to eight bit byte Such as, value 1)；And value field 96, it is set to indicate that the value of the connection status of core segment (for example, network 10).For example, setting Indicate that core segment is forwarding packet for the value field 96 of value 1.As another example, the value field 96 for being set as value 2 indicates core Section does not forward packet.As another example, the value field 96 for being set as value 4 indicates that core segment is in standby.As another reality Example, the value field 96 for being set as value 8 indicate that there are remote ethernet segment faults.Corresponding to the example T LV 90 of mac refresh TLV Including：Type field 92 is arranged to identify the value (for example, value 11) that TLV is mac refresh TLV；Length field 94, according to eight Bit byte is arranged to the length of value field 96；And value field 96, the various of which MAC Address will be refreshed by being set to indicate that Value.For example, value field 96 is arranged to value 0, instruction receives network equipment and is known with refreshing on the chain road for receiving CC message All MAC Address.Value field 96 can also be set to correspond to particular vlan ID or I-SID (Service Instance VLAN ID) Value.When setting value field 96 to the value of particular vlan ID or I-SID, the network equipment of CC message is received (for example, MTU 16A) refresh MAC Address associated with VLAN ID or I-SID.It can also set value field 96 to particular mac address Value will refresh specific MAC Address with instruction.

In some aspects, preferred network path TLV, connection status TLV or mac refresh TLV can be defined as tissue and specify TLV. It is the example that tissue specifies TLV 100 with reference to B, TLV 100.Tissue specifies the TLV 100 to include and above-mentioned that about TLV 90 The similar type field 102 of a little fields, length field 104 and value field 110.For organizing to specify TLV, by type field 102 are set as value 31.It further includes organization unique identifier (" OUI ") field 106 and sub-type field that tissue, which specifies TLV 100, 108.According to eight bit byte, it sets length field 104 to the total of OUI field 106, sub-type field 108 and value field 110 Length.OUI field 106 includes that the unique identifier of each tissue is distributed to by IEEE.Sub-type field 108 is identified in OUI words The type of TLV defined in the tissue identified in section 106.Each tissue can identify one or more TLV subtypes.OUI words The combination of section 106 and sub-type field 108 uniquely identifies the type of TLV.

MTU 16,17 and pe router 14 can generate about described in B be tissue specify TLV (for example, TLV 100) it is excellent Select network path, connection status and mac refresh TLV.When generation preferred network path, connection status, mac refresh TLV conducts When tissue specifies TLV, sub-type field 108 is set as being worth determined by the tissue identified in OUI field 106, by tissue Specified TLV is identified as preferred network path TLV, connection status TLV or mac refresh TLV, for example, be respectively value 1,2 or 3 it One.By with it is above-mentioned about TLV 90 it is similar in a manner of, the value of the value field 110 of each type of TLV can be set to indicate that Included in preferred network path, connection status or the value that refresh which MAC Address.

According to technology described in the disclosure, the flow chart of the exemplary operation of the device of preferred path information is transmitted in network. For clarity, the MTU 16A about shown in and pe router 14A and 14B description.MTU 16A determine preferred network path (120).MTU 16A can determine preferred network path in various ways, for example, various ways include being randomly or based on pipe Network condition of the configuration parameter of reason person's input in response to such as network error or network congestion.Preferred net is determined in MTU 16A After network path, the MEP modules 26 of MTU 16A generate the CC message (122) for (for example) including CC message PDU70.MEP modules 26 It can be configured as and periodically generate CC message or administrator can make MEP modules 26 generate CC message manually.In an example In, if configuring MEP modules 26 to periodically generate CC message, determine that preferred network path includes preferred net in MTU16A After the TLV of network path, the first CC message is generated.If administrator makes MEP modules 26 generate CC message, determined in MTU 16A After preferred network path includes preferred network path TLV, the first CC message is made to generate.It can be according to exemplary shown in A and B TLV generates preferred network path TLV.In an example, MTU 16A determine pe router 14A in preferred network path, and Pe router 14B is not in preferred network path (120).In this example, MEP modules 26 generate instruction pe router 14A and exist CC message (122) in preferred network path.Then, MTU 16A via an IFC 22 and outbound link 24 by the CC of generation Message is sent to pe router 14A (124).Pe router 14A receives CC message via an IFC 46 and inbound 47 (126), MEP modules 56 is used in combination to analyze the CC message (128) received.MEP modules 56 can be configured as based in CC message The TLV presence or absence of preferred network path, or based on the preferred network path TLV's being included in CC message about A and B descriptions Value, to determine pe router 14A whether in preferred network path.

If MEP modules 56 determine pe router 14A (130 "No" branches), pe router not in preferred network path 14A can discharge various device resources, such as previously handle the net for wrapping and reserving associated with the Service Instance of CC message Network bandwidth (132).For example, in response to the pe router 14A not decisions in preferred path network that MEP modules 56 are made, MEP modules 56 can be interacted with the agreement (such as Resource Reservation Protocol) executed in control unit 40, to order the agreement Realize the release of resource.If MEP modules 56 determine pe router 14A (130 "Yes" branches) in preferred network path, Pe router 14A can allot previous available device resource for handling packet associated with the Service Instance of CC message (134)。

In the case where MTU 16A determine pe router 14B not in preferred network path (120), MEP modules 26 generate instruction CC message (122) of the pe router 14B not in preferred network path.Then, MTU 16A are via an IFC22 and outbound chain The CC message of generation is sent to pe router 14B (124) by road 24.Pe router 14B is via an IFC 46 and inbound 47 receive CC message (126), and MEP modules 56 is used in combination to analyze the CC message (128) received.Once it is determined that pe router 14B is not In preferred network path, pe router 14B can redistribute resource.As an example, pe router 14B can be selected Select the idle devices resource for not remaining for handling packet associated with the Service Instance of CC message in advance.As another example, PE Router 14B can discharge various device resources, and it is pre- such as previously to handle packet institute associated with the Service Instance of CC message The network bandwidth (132) stayed.According to technology described in the disclosure, the L3 devices that are run in layer three (L3) network are by L3 networks Network state is sent to the flow chart of the exemplary operation of the L2 devices run in layer two (L2) network.For clarity, about Shown in network 10, pe router 14A and MTU 16A describe.Pe router 14A is using L3 agreements (for example, such as BGP Or the Routing Protocol of LDP) L3 connection status message (140) of the reception about network 10, and in response, the router of PE The MEP modules 56 of 14A generate L2 message, it may for example comprise the CC message frames (142) of connection status TLV.Pe router 14A is used About CC message TLV described in A and B, the connection status of network 10 is sent to MTU 16A.For example, can be by pe router The MEP modules 56 of 14A be configured to according to using MEP modules 56 generate each CC message or connection status in any change and Generate connection status TLV.Then, CC message is sent to MTU 16A (144) by pe router 14A, and MTU 16A receive CC message (146).The MEP modules 26 of MTU 16A analyze the CC message (148) received, to determine the connection status of network 10, for example, Network error or connectivity recovery.Value of the MEP modules 26 based on connection status TLV included in the CC message in reception is come really Determine connection status.For example, determining that core network (for example, network 10) does not turn if the value of connection status TLV is 2, MEP modules Send out flow.As another example, if the value of connection status TLV, which is 4, MEP modules 26, determines that network 10 is in standby shape State.Analysis (148) based on CC message, MTU 16A can determine whether to change previously determined preferred network path (150).For example, if connection status TLV instruction networks 10 are not forwarded, it is preferred that MTU 16A can determine that needs change Network path is route (150 "Yes" branches) to get around the part of network 10 not being forwarded.In another example In, connection status TLV instruction networks 10 are being forwarded.If pe router 14A is in preferred network path, MTU 16A, which can be determined, haves no need to change preferred network path (150 "No" branches).If (for example) indicate network error (for example, Remote ethernet segment fault or network 10 are not forwarded) connection status TLV by the PE that is not currently in preferred network path Router 14 generates, then MTU 16A, which can also be determined, haves no need to change preferred network path (150 "No" branches).MTU 16A Change preferred network path (152) by modifying to the CC message for generating and being arranged for pe router 14A, 14B.Example Such as, if pe router 14A is originally in preferred network path, but based on the CC message to being received from pe router 14A into Capable analysis (148), is no longer on and selects in excellent network path, then the MEP modules 26 of MTU16A, which stop generating, has instruction PE The CC message of preferred network path TLVs of the router 14A in preferred network path, and stop sending the message to PE routings Device 14A, on the contrary, generating the CC message that instruction pe router 14A is no longer in preferred network path and sending the message to Pe router 14A.If pe router 14B, in new preferred path, MEP modules 26 stop generating instruction pe router CC message and stopping of the 14B not in preferred network path send the message to pe router 14B, on the contrary, generating instruction PE CC message of the router 14B in preferred network path simultaneously sends the message to pe router 14B.About A and B describe to Pe router 14A, 14B indicate each pe router 14A, 14B whether the CC message and TLV formats in preferred network path. According to technology described in the disclosure, transmit particular network state and the pe router of mac refresh 14 and MTU 16 in network 10, The flow chart of 17 exemplary operation.For clarity, the network 10 about shown in, pe router 14A and MTU 16A descriptions Shown in method.Pe router 14A receives the connection of the mistake in instruction network 10 via Routing Protocol (such as BGP or LDP) Status message (160).It may not forward packet (for example, because of link failure or because of the one of network 10 by a part for network 10 It is partially in standby mode or due to remote ethernet segment fault) and lead to network error.Pe router 14A generations include referring to Show the CC message (162) of the connection status TLV of network error, and CC message is sent to MTU 16A (164).MTU 16A are received CC message (166) analyzes the CC message (168) of reception, and determines that the CC message received includes the mistake indicated in network 10 Connection status TLV.Based on network error, MTU 16A determinations need to change preferred network path, and the MEP modules 26 of MTU 16A are given birth to At the CC message for indicating the variation in preferred network path as described earlier and send the message to pe router 14A, 14B(170)。

After the CC message for generating and sending instruction network error, pe router 14A generates another CC message, to indicate MTU One group of MAC Address (172) that 16A should refresh from the MAC Address known.If the mistake in network 10 is limited to specific MAC Address, VLAN ID or I-SID, then MEP modules 56 generate the mac refresh TLV for indicating specific MAC Address, or with VLAN ID Or associated to be refreshed the one group MAC Address of I-SID.If the erroneous effects in network 10 are connected to the all-network of link Device, then MEP modules 56, which can generate instruction, will refresh the mac refresh TLV for all MAC Address known on the link.In life After mac refresh CC message, mac refresh CC message is sent to MTU 16A (174) by pe router 14A.MTU 16A are received CC message (176) simultaneously analyzes the CC message (178) received.The MEP modules 26 of MTU 16A are based on the value of mac refresh TLV come really The MAC Address refreshed from MAC data 32 is needed calmly, and refreshes corresponding MAC Address (180) from MAC data 32.Show into The method gone out can combine implementation or individually implement.In addition, multiple steps can be combined into single step.For example, pe router 14A can generate and be sent to MTU 16A include connection status TLV and mac refresh TLV single CC message.MTU 16A's MEP modules 26 can handle connection status TLV and mac refresh TLV, and be based on single CC message alterations preferred network path.Though So be discussed about pe router 14A, 14B and MTU 16A, but any PE for being configured according to the technology of the disclosure or MTU can implement the method shown in.

In this way, can be with service life L2 frames (for example, Ethernet OAM frame) by connection state information, preferred network routing information And mac refresh information is communicated between L2 devices and L3 devices.The technology of the disclosure can reduce other not by network Erroneous effects but any loss of the network packet of service run on the same link with the packet influenced by network error.In addition, The technology of the disclosure can more effectively utilize available network resource.The technology (at least partly) of disclosure description can be hard It is realized in part, software, firmware or its arbitrary combination.For example, the various aspects of the technology can be in one or more processors Interior realization, processor include one or more microprocessors, digital signal processor (DSP), application-specific IC (ASIC), field programmable gate array (FPGA) or other any equivalent integrated circuits or discrete logic circuit and this The arbitrary combination of kind component.Term " processor " or " processing circuit " can usually refer to any type foregoing logic circuitry, individually Or it is combined or any other equivalent circuit with other logic circuits.Control unit including hardware can also be performed it is a kind of or The technology of a variety of disclosure.These hardware, software and firmware can be implemented in same apparatus, or implement in separator, To support various operations and the function described in the disclosure.In addition, any unit, module or component can with common implementing, or It is implemented separately as discrete component but interoperable logic device.As module or the description purport of the different characteristic of unit In terms of emphasizing different functions, and do not necessarily mean that this module or unit centainly by independent hardware or software module To implement.On the contrary, can be realized by independent hardware or software component with one or more modules or the relevant function of unit, Or it is integrated in general or independent software or hardware component.Technology described in the disclosure can also be in the calculating comprising instruction Implement in machine readable medium (such as computer readable storage medium) or encodes.For example, when executing an instruction, computer-readable Instruction that is embedded or encoding can make programmable processor or other processors execute this method in medium.Computer-readable storage Medium may include random access memory (RAM), read-only memory (ROM), programmable read only memory (PROM), erasable It is programmable read only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, hard disk, CD-ROM, soft Disk, tape, magnetic medium, optical medium or other computer-readable mediums.It should be understood that term " computer-readable storage medium Matter " refers to physical storage medium, rather than signal, carrier wave or other transient mediums.

Various embodiments of the present invention have been described.In these and other embodiment is within the scope of the appended claims.

Claims (10)

1. the communication network path in a kind of more place networks and status information, including：Behaviour is executed on first layer two (L2) device Make, manage and safeguard (OAM) agreement to monitor the first L2 networks, wherein the first L2 devices are in the first L2 networks Operation；Determine that it is preferred network path to lead to the network path of the 2nd L2 devices via layer three (L3) device, wherein described second L2 devices are run in the 2nd L2 networks, wherein the first L2 networks and the 2nd L2 networks pass through intermediate L3 networks coupling It closes, and wherein, the L3 devices couple the first L2 networks with the L3 networks；And

L2 frames are issued to the L3 devices, wherein the L2 frames using the OAM agreements executed on the first L2 devices Notify the L3 devices in the preferred network path to the L3 devices.

2. the communication network path in a kind of more place networks and status information according to claim 1, wherein the L2 frames packet The continuity check message that the OAM agreements use is included, to detect the connectivity fault between sending device and destination device；With And wherein, the L2 frames include：(1) continuity check message field, including commonly connected property fault management header, sequence number, Maintenance association endpoint identifier, maintenance association identifier and measured message, and (2) type-length-value (TLV) Field, carrying indicate the L3 devices whether the additional data in the preferred network path.

3. according to the method described in claim 1, further comprising, the OAM executed on the first L2 devices is used Agreement issues L2 frames to the 2nd L3 devices, wherein to the L2 frames of the 2nd L3 devices publication to the 2nd L3 devices Notify the 2nd L3 devices not in the preferred network path.

4. the communication network path in a kind of more place networks according to claim 1 and status information, further comprise：Institute It states the first L2 devices and receives the L2 frames issued by the OAM agreements executed on the L3 devices, wherein issued by the L3 devices The L2 frames network error in the L3 networks is notified to the first L2 devices；And the first L2 devices be based on by Network error indicated by the L2 frames of the L3 devices publication, to determine that the L3 devices are no longer on the preferred network In path.

5. the communication network path in a kind of more place networks according to claim 4 and status information, further comprise：One Denier determines that the L3 devices are no longer in the preferred network path, just described using being executed on the first L2 devices OAM agreements issue the 2nd L2 frames to the L3 devices, wherein the 2nd L2 frames issued to the L3 devices are filled to the L3 It sets and notifies the L3 devices not in the preferred network path；The 2nd L2 devices will be led to not via the 2nd L3 devices Same network path is determined as the preferred network path；And use the OAM agreements executed on the first L2 devices L2 frames are issued to the 2nd L3 devices, wherein the L2 frames issued to the 2nd L3 devices are to the 2nd L3 devices Notify the 2nd L3 devices in the preferred network path.

6. the communication network path in a kind of more place networks according to claim 1 and status information, further comprise：Institute It states the first L2 devices and receives the L2 frames issued by the OAM agreements executed on the L3 devices, wherein issued by the L3 devices The L2 frames bearer types-Length Value (TLV) field, the type-length-value field indicates the media interviews to be removed (MAC) address subset is controlled, the first L2 devices is and guided to remove the MAC Address subset；And in response to from the L3 The L2 frames that device receives remove MAC Address from one group of MAC Address being stored in the first L2 devices Collection.

7. the communication network path in a kind of more place networks according to claim 6 and status information, wherein the TLV Field assigned vlan identifier；And wherein, removing the MAC Address subset specified in the L2 frames includes, the L2 dresses It sets and refreshes MAC Address associated with the vlan identifier from the one group of MAC Address known.

8. according to the method described in claim 1, further comprising：

When the OAM protocol detections executed on the L3 devices to the L3 network internal storages are in network error, the first L2 dresses Set the L2 frames for receiving and being generated by the OAM agreements executed on the L3 devices, wherein the L2 frames are on the L3 devices Continuity check message used in the OAM agreements executed, to detect the connectivity between sending device and destination device Failure, and wherein, the L2 frames include type-length-value (TLV) field for indicating the network error.

9. the communication network path in a kind of more place networks according to claim 8 and status information, further comprise：It rings Ying Yu receives the L2 frames for indicating the network error, determines the L3 devices not in the preferred network path；Make It is sent with the first L2 devices and indicates the L3 devices not in the preferred network path for leading to the 2nd L2 devices L2 frames；And in response to the determination, release previously reserved Internet resources available to the L3 devices.

10. the communication network path in a kind of more place networks according to claim 9 and status information, wherein divide again Include the network bandwidth redistributed to handle from the packet that the L2 devices receive and previously reserved with resource, and wherein, institute Previously reserved resource is stated to be in response to determine that the L3 is filled based on the previous L2 frames received from the L2 devices in the L3 devices It sets in the preferred network path and reserved.