KR20130085488A - Oam frame handling apparatus and method for packet transport network - Google Patents

Abstract

The present invention provides an OAM frame processing apparatus of a packet forwarding network, wherein a network OAM management unit selects an OAM frame requiring real-time processing based on label information included in a received packet and manages a state of the selected OAM frame. ; And a non-real-time OAM processing unit for managing a state of the OAM frame that does not require real-time processing and controlling the setting of the network OAM management unit.
According to the present invention, in the OAM frame processing, the OAM function that requires real-time processing and the OAM function that does not require real-time processing can be separately processed, thereby effectively distributing the burden of the frame processing.

Description

OAM FRAME HANDLING APPARATUS AND METHOD FOR PACKET TRANSPORT NETWORK}

The present invention relates to an OAM frame processing apparatus and method for a packet transport network, and more particularly, to operation management and service management of a service in a packet transport network using a Multiprotocol Label Switching-Transport Profile (MPLS-TP) technology. The present invention relates to an OAM frame processing apparatus and method for dividing a network processor and a general purpose processor by a function in order to efficiently provide fault monitoring and quick recovery.

According to the ITU-T definition of the specification of the transport network device, the OAM of the transport network device must provide fault management and performance monitoring. Fault management includes Continuity Check-Connectivity Verification (CC-CV), Loopback (LB), Link Trace (LT), Alarm Indication Signal (AIS), Remote Defect Indication (RDI), and Lock (CKC) for fault monitoring and recovery of services. Signals, or functions such as Automatic Protection Switching (APS), and performance monitoring includes functions such as Loss Measurement (LM) and Delay Measurement (DM) to ensure the quality of service.

Currently, the packet forwarding network is built with MPLS-based devices, and the OAM of this device supports Bidirectional Forwarding Detection (BFD) corresponding to CC-CV function, Label Switched Path (LSP) ping corresponding to LB function, and APS. It only uses some fault management functions based on IETF IP / MPLS OAM, such as Fast Re-Routing (FRR), which does not provide a complete OAM tool for the transport network. In addition, in case of BFD, fault detection time is slow, so it is not possible to meet the fast fault detection and protection recovery time (less than 50ms) required by the transport network device.In case of LSP ping and FRR, it works in connection with IP (Internet Protocol). Inefficient

In order to solve the above-mentioned problems of the prior art, the CC-CV, LM functions that need to be processed in real time among the functions of the OAM in the OAM method of the MPLS-TP-based packet delivery network are processed using hardware other than the network processor and in real time. Another function that does not require processing is to provide an OAM frame processing apparatus and method for processing using software on a general purpose processor.

According to an embodiment of the present invention for solving the above technical problem, in the OAM frame processing apparatus of a packet delivery network, OAM frames for real-time processing is selected based on the label information included in the received packet, A network OAM manager that manages the state of the selected OAM frame; And a non-real-time OAM processing unit that manages the state of the OAM frame that does not require real-time processing and controls the setting of the network OAM management unit.

The network OAM management unit may further include: a database unit storing data for implementing a real-time processing function; An OAM interrupt generator configured to generate a state interrupt of the OAM frame at predetermined intervals; A frame analyzer configured to analyze the OAM frame and determine the type of the OAM frame by analyzing the generated state interrupt when the state interrupt is generated; A frame processor configured to process the OAM frame according to the type of the OAM frame, and generate an output frame by associating information corresponding to the processed OAM frame with the OAM frame; It may include a frame output unit for transmitting to the network unit or the non-real-time OAM processing unit according to the output frame.

The frame processing unit may further include: a transmission interrupt processing unit for generating association information by looking up information corresponding to the transmission interrupt when the type of the OAM frame is a transmission interrupt; A fault interrupt processor configured to look up information corresponding to the fault interrupt and generate related information when the type of the OAM frame is a fault interrupt; An OAM reception processing unit for generating association information by looking up information for the OAM reception processing when the type of the OAM frame is an OAM reception frame including an MPLS label; A data frame processor for generating association information by looking up information for data processing of the OAM frame when the type of the OAM frame is an OAM reception frame or a transmission frame that does not include an MPLS label; And a header processing unit for associating the association information generated from the OAM transmission interrupt processing unit, the OAM failure interrupt processing unit, the OAM receiving processing unit, or the data frame processing unit with the OAM frame.

The transmission interrupt processing unit may further include: a key extracting unit configured to extract an RTC index with respect to the OAM frame and determine a key; A data extracting unit obtaining data information corresponding to the generated key; And a check message transmitter for generating a real time processing frame based on the extracted data and transmitting the generated real time processing frame.

The fault interrupt processing unit may include: a key extracting unit configured to extract a link failure index with respect to the OAM frame and determine a key; A data extracting unit obtaining data information corresponding to the generated key; And a failure message transmitter configured to generate a failure processing frame based on the extracted data and transmit the generated failure processing frame.

The OAM receiving processor may further include: a frame information checker extracting an identifier of the OAM received frame and checking a control path of the OAM received frame; An OAM processor configured to process the OAM frame based on a function identifier of the OAM received frame when the control path of the OAM received frame corresponds to a preset control path; And if the control path of the OAM receiving frame does not correspond to a predetermined control path, it may include an OAM transfer unit for performing an OAM process for transmitting the frame to the non-real-time OAM processing unit.

Preferably, the OAM processing unit, if the function identifier is a RAPS frame, the RAPS processing unit for looking up the association information of the RAPS frame, to associate with the RAPS frame to process; And a RAPS exclusion frame processor configured to look up an identifier of the OAM received frame to obtain association information when the function identifier is not a RAPS frame.

Preferably, the RAPS processing unit comprises a RAPS node check unit for checking the source node and the destination node of the RAPS frame; And a RAPS frame processing unit for looking up information corresponding to the identifier of the RAPS frame and associating the lookup information with the RAPS frame and transmitting the same.

Preferably, the RAPS exclusion frame processing unit OAM association information generation unit for obtaining information by looking up the identifier of the OAM received frame; A label check unit which checks a label state of the OAM received frame; And an OAM frame processor configured to perform a preset frame process according to the label checked by the label checker.

Another embodiment of the present invention for solving the above technical problem, in the OAM frame processing method of a packet delivery network, based on the label information included in the received packet, select the OAM frame that requires real-time processing, A network OAM management step of managing a state of the selected OAM frame; And a non-real-time OAM processing step of managing a state of the OAM frame that does not require real time processing and controlling the setting of the network OAM management step.

According to the configuration of the present invention, not only the ITU-T-based OAM scheme, which is proven in the MPLS-TP-based packet delivery network, can be applied based on the forwarded packet, but also the IP / MPLS OAM scheme, which is being improved, may be applied later. have. In addition, the OAM function (CC-CV), which requires real-time processing, and OAM functions (non-CC-CV) that do not require real-time processing, can be classified and processed to effectively distribute the burden of frame processing. Can be.

1 is a reference diagram showing an embodiment of a system using a conventional MPLS-TP OAM management domain of the present invention.
2 is a block diagram illustrating an OAM frame processing apparatus of a packet delivery network according to an embodiment of the present invention.
3 is a block diagram illustrating a frame processing unit in an OAM frame processing apparatus according to an embodiment of the present invention.
4 is a flowchart illustrating transmission interrupt processing in an OAM frame processing apparatus according to an embodiment of the present invention.
5 is a flowchart illustrating a fault interrupt processing step in an OAM frame processing apparatus according to an embodiment of the present invention.
6 is a flowchart illustrating an OAM reception processing step in an OAM frame processing apparatus according to an embodiment of the present invention.
7 is a flowchart illustrating a RAPS processing step in an OAM frame processing apparatus according to an embodiment of the present invention.
8 is a flowchart illustrating a RAPS exclusion frame processing step in an OAM frame processing apparatus according to an embodiment of the present invention.
9 is a flowchart illustrating the overall steps of a method for processing an OAM frame in a packet delivery network according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

The following embodiments are a combination of elements and features of the present invention in a predetermined form. Each component or feature may be considered to be optional unless otherwise stated. Each component or feature may be implemented in a form that is not combined with other components or features. In addition, some of the elements and / or features may be combined to form an embodiment of the present invention. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments.

Embodiments of the invention may be implemented through various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

For a hardware implementation, the method according to embodiments of the present invention may be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs) , Field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of an implementation by firmware or software, the method according to embodiments of the present invention may be implemented in the form of a module, a procedure or a function for performing the functions or operations described above. The software code can be stored in a memory unit and driven by the processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various well-known means.

Specific terms used in the following description are provided to help the understanding of the present invention, and the use of the specific terms may be modified in other forms without departing from the technical spirit of the present invention.

Referring to FIG. 1, a conventional MPLS-TP OAM management domain, an ITU-T Y.1731-based MPLS-TP OAM frame format, and an OAM frame are referred to as a Maintenance Entity Group End Point (MEP) or MIP (MEP) as a destination. A description will be given of an embodiment that delivers up to a MIP (Maintenance Entity Group Intermediated Point).

1, G-Ach is Generic Associated Channel Header, GAL is G-Ach Label, PW is Pseudowire, SME is Section Maintenance Entity Group, LME is LSP Maintenance Entity Group, PME is PW Maintenance Entity Group, CE is Customer Edge, LER Is a Laber Edge Router, LSR is a Label Switch Router, SPE is a Switching Provider Edgde Router, and TPE is a Terminating Provider Edge router.

The MPLS-TP OAM management domain is a domain such as a Section Maintenance Entity Group (SME), an LSP Maintenance Entity Group (LME), and a PW Maintenance Entity Group (PME) to manage service data exchanged between CEs through the MPLS-TP network. It can be distinguished and managed independently.

SME is a domain that manages physical ports between MPLS-TP devices, LME is a domain that manages LSP tunnels between Label Edge Routers (LER), and PME is a domain that manages PW (Pseudowire) between Terminating Provider Edge Routers (TPEs). to be.

The MEP can be set only at the start point and the end point of the MPLS-TP devices constituting each domain, and the MIP can be set only at the midpoint (for example, TPE-1 for PME and MIP for MPE remainder). The OAM frame is generated at the egress (output) of the NNI line card of the MPLS-TP device set to MEP, and terminated at the ingress (input) of the NNI line card.

MPLS-TP OAM uses Section OAM frame, LSP OAM frame and PW OAM frame format to manage SME, LME and PME. Each OAM frame is a server layer header (eg, MAC header-DA, SA, EtherType, VLAN-ID, etc.) for physically exchanging frames, and a GAL (G-ACh Label), which is a fixed MPLS label that represents an OAM frame. G-ACh (Generic Associated Channel), which means the type of associated channel, G-ACh TLV (Type / Length / Value) for providing additional information of G-ACh, OAM PDU (Protocol Data Unit) with data per OAM function ) In common.

In the case of the section OAM frame, only the fields described above are used.In the case of the LSP OAM frame, the LSP Label is inserted between the Server Layer Header and the GAL. In the case of the PW OAM frame, the LSP Label and the PW Label are inserted between the Server Layer Header and the GAL. .

In general, since the GAL is located after the MPLS Label to be managed, the LSP OAM frame is located after the LSP Label and the PW OAM frame is located after the PW Label.

GAL is a Label Value set to 13, TC (Traffic Class), a QoS parameter, S (Bottom of Stack; 1 = Bottom), which means the label position, and TTL (Time to Live), which means the hop count to the destination. It consists of. G-ACh is composed of a delimiter indicating that ACh (= 0b'0001), Version (= 0), Reserved (= 0), and Channel Type to distinguish OAM methods. OAM PDU is MEL (unused), Version (= 0), PDU common fields used in ITU-T Y.1731, OpCode which means OAM frame type, Flag with setting and status information, and up to the next TLV. It consists of TLV Offset, which means the number of bytes, and OAM Function Specific Fields that depend on the OAM function.

Based on the above description, an embodiment of transmitting an LSP OAM frame to a destination (MEP or MIP) in an LME domain in which two LERs are set to MEP and one LSR is set to MIP will be described.

If the destination of the LSP OAM frame generated by MEP_A is MIP, LER-1 confirms that the hop count to LSR-2 is 1, and transmits the OAM frame pushed by setting the TTL of the LSP Label to 1 do. The LSR-2 performs a MIP OAM process by checking that the TTL of the LSP Label of the received frame is 1 and the next Label is GAL. For reference, there is only LBM (loopback message) in OAM frame that is the destination of MIP.

If the destination of the LSP OAM frame generated by MEP_A is MEP_B, LER-1 sets the TTL of the LSP Label to 255 and transmits the frame. Since the TSR of the received frame is 255, the LSR-2 decreases 1, and since the lookup result of the LSP Label is Swap (forwarding), the label value is changed and transmitted. The LER-3 performs a MEP OAM process by checking that the TTL of the received frame is 254 so that 1 is reduced and the lookup result for the LSP Label is Pop and the next Label is GAL.

An OAM frame processing apparatus in a packet delivery network according to an embodiment of the present invention will be described with reference to FIG. 2. The OAM frame device is composed of a network OAM management unit 10 and a non real-time OAM processing unit 20. The packet delivery network including the label includes a Multiprotocol Label Switching-Transport Profile (MPLS-TP). In the present invention, an ITU-T scheme, not an incomplete IETF IP / MPLS OAM scheme, is applied to an OAM scheme of a packet transfer network using a packet including a label such as an MPLS-TP-based packet transfer network.

The network OAM manager 10 selects an OAM frame that requires real time processing based on a label included in the received packet, and manages a state of the selected OAM frame. The network OAM management unit is implemented using a programmable processor to support packet, routing algorithm calculation, and protocol processing on the network, and includes a network processor. Managing the state of the OAM frame means that the information related to the OAM frame is looked up in the database and associated with the OAM frame, or when the OAM frame is an interrupt, interrupt processing or processing for forwarding is performed. The network OAM manager 10 includes a database 100, a frame analyzer 110, a frame processor 120, a frame outputter 130, an OAM interrupt generator 140, and a statistics counter 150. .

The database unit 110 stores data for implementing a real time processing function. According to an embodiment of the present invention, the database unit is associated with L2 Header, MPLS Labels, CCM Tx DB having CCM PDU information for transmitting a Continuity Check Message (CCM) to the other MEP, the link for notifying the link failure information to the other MEP CCM RxDB with CCM Wd DB with CCM Tx DB index information, Expected MEG ID / MEP ID / CCM Interval for determining whether there is a defect for the receiving CCM from the other MEP, WD counter address for monitoring CCM, and the like. DATA DBs having frame processing information such as an incoming label map (ILM), an FEC to NHLFE map (FTN), and a next hop label forwarding entry (NHLFE) for an input frame are included.

The frame analyzer 110 analyzes the OAM frame and, when the state interrupt generated by the OAM interrupt generator 140 is input, analyzes the generated state interrupt to determine the type of the OAM frame. According to an embodiment of the present invention, when the generated state interrupt is input, the CCM Index is extracted, and there is no generated state interrupt, and if the OAM frame is a reception frame, Input Port, L2 Ethernet Header, MPLS Labels, OAM Fields, etc. If the OAM frame is a transmission frame, the source port, MPLS Labels, and the like are extracted and then transferred to the data frame processor 120.

The frame processor 120 processes the OAM frame according to the type of the OAM frame determined by the frame analyzer, and generates an output frame by associating information corresponding to the processed OAM frame with the OAM frame.

The frame output unit 130 transmits the data to the network unit or the non-real-time OAM processing unit 20 according to the output frame generated by the frame processing unit 120. The network portion includes a network or a switch.

The OAM interrupt generator 140 generates a state interrupt of the OAM frame at predetermined intervals. The preset period means a period set by the user to check whether a failure occurs. The OAM status interrupt refers to a real time clock (RTC) interrupt or watchdog (WD) interrupt used to check the status of an OAM frame. According to an embodiment of the present invention, the OAM interrupt generator 140 periodically generates a Real Time Clock (RTC) interrupt to generate a CCM having a specific period (3.3 ms / 10 ms / 100 ms / 1 s / 10 s). When a failure occurs while managing the received CCM link state through the CCM Index or the CCM Index, the CCM Index is transmitted to the frame analyzer 110 by generating a WD (Watchdog) interrupt to the frame analyzer 110 along with the CCM Index. To pass.

The statistics counter 150 stores statistics related information related to the data plane processor 10 such as a data transmission / reception counter, a CCM transmission counter, or a CCM WD counter.

The non-real-time OAM processing unit 20 processes an OAM frame that does not require real-time processing based on a label included in the packet by using a general purpose processor, and controls the setting of the network OAM management unit 10. According to an embodiment of the present invention, the OAM interrupt generator 140, the statistic counter 150, and the database 100 of the data plane processor 10 are controlled in a setting other than the CCM (Continuity Check Message). Generates an OAM frame and delivers it to the frame output unit 130, or processes OAM frames and CCM interrupts other than the CCM received from the frame output unit 130.

Referring to FIG. 3, the frame processing unit 120 in the OAM frame processing apparatus according to an embodiment of the present invention will be described. The frame processing unit 120 includes a transmission interrupt processing unit 121, a reception interrupt processing unit 122, an OAM reception processing unit 123, a data frame processing unit 124, and a header processing unit 125.

When the frame analysis unit 110 determines that the type of the input frame is a transmission interrupt, the transmission interrupt processing unit 121 looks up information corresponding to the transmission interrupt and generates related information. According to an embodiment of the present invention, the transmission interrupt processing unit 121 receives the CCM Index of the frame determined as the transmission interrupt in the frame analysis unit 110, and the information corresponding to the received CCM Index CCM Tx in the database Look up in the DB to obtain the transmission CCM information. The association information is generated by associating the obtained CCM information with the CCM Index. The association information refers to information obtained by looking up a database to identification information of a frame such as a CCM index, an input port, or an L2 header in order to associate the OAM frame with the header processing unit 125.

When the type of the input frame is determined to be a fault interrupt in the frame analyzer 110, the fault interrupt processor 122 looks up information corresponding to the fault interrupt in the database and generates related information. According to an embodiment of the present invention, the fault interrupt processing unit 122 receives the CCM Index from the frame analyzer 110 and based on the information obtained by looking up information corresponding to the received CCM Index in the database. Updates the link failure status field of the associated CCM Tx DB and creates link failure information.

When the frame analyzer 110 determines that the type of the input frame is an OAM reception frame including an MPLS label, the OAM reception processing unit 123 looks up information for the OAM reception processing to generate related information. According to an embodiment of the present invention, the OAM reception processing unit 123 may include information corresponding to an input port or MPLS labels received from the frame analyzer 110 in a database such as DATA DBs, CCM Rx DB, RAPS Rx DB, or CCM Tx. Determines whether MEP / MIP processing or forwarding processing is performed based on the information obtained by looking up from the DB. CCM defect information, OAM reception information other than the CCM is transmitted to the control management processing unit 20 or generates information for forwarding processing. However, if there is no defect in CCM, measure the loss, save it in CCM Rx DB and terminate.

When the frame analyzer 110 determines that the type of the input frame is an OAM reception frame or a transmission frame that does not include an MPLS label, the data frame processing unit 124 looks up the information for processing the data of the OAM frame to obtain related information. Create

The header processing unit 225 associates the association information generated from the OAM transmission interrupt processing unit, the OAM failure interrupt processing unit, the OAM reception processing unit, or the data frame processing unit with the OAM frame. According to an embodiment of the present invention, the header processing unit adds, deletes or modifies the header of the frame and then transfers the information to the frame output unit 130 along with the output information.

A transmission interrupt processing unit in an OAM frame processing apparatus according to an embodiment of the present invention will be described with reference to FIG. 4.

The transmission interrupt processing unit 121 checks the interrupt permission setting as to whether to process the transmission interrupt frame (S101). If the interrupt is not allowed, the transmission interrupt processing unit 121 discards the transmission interrupt (S105). Extracting the RTC index allocated for each frame for the transmission interrupt frame automatically generated at each cycle (S102), performing a database lookup using the extracted RTC index as a key, and performing L2 Ethernet Header, MPLS Labels, and CCM PDU ( Data including information (TxCFCL) such as CCM Interval, MEGID, MFPIF, LM related fields, etc.) and a corresponding data frame transmission counter address is extracted (S103). The transmission interrupt processing unit 121 generates a CCM frame as a check message by referring to the information extracted in step S103 and transmits the generated check message.

Referring to FIG. 5, a failure interrupt processing unit in an OAM frame processing apparatus according to an embodiment of the present invention will be described.

The fault interrupt processing unit 122 checks the interrupt allowance setting for processing the fault interrupt frame (S201), and discards the fault interrupt if the interrupt is not allowed (S205). If a failure interruption is allowed, the key extraction unit extracts a link failure index in which link failure has occurred (S202). The link failure index includes the CCM Watchdog Counter index. The data extracting unit corresponds to a link failure index and extracts data for immediately reporting a link failure to the other party. (S203) Extracting data performs a database lookup to obtain information of an associated CCM Tx DB. Based on the obtained information, the RDI field of the associated Tx CCM DB is updated to 1. Create and deliver a message to report to the control management plane processing that a link failure has occurred.

Referring to FIG. 6, an OAM reception processing unit in an OAM frame processing apparatus according to an embodiment of the present invention will be described. The OAM receiving processor includes a frame information checker, an OAM processor, and an OAM transmitter.

The frame information checker extracts an identifier of a frame such as an input port, MPLS Labels, etc. with respect to the received frame (S301), and checks the control path to determine what is used as an associated channel which is a control path (S302).

If the checked control path corresponds to a preset control path, the OAM processing unit processes the OAM frame based on the function identifier of the OAM received frame (S303).

If the control path of the OAM receiving frame does not correspond to the preset control path, the OAM transfer unit transmits the frame to the non-real-time OAM processing unit 20 (S304).

According to an embodiment of the present invention, when the G-ACh Channel Type value indicating the control path means ITU-T Y.1731 OAM, it checks the OpCode, which is the OAM function identifier in the OAM PDU common field, and checks RAPS (Retrun Address Pointer). Stack) process is divided into OAM process other than RAPS and then the process is performed. If the G-ACh Channel Type value is not ITU-T Y.1731 OAM, it is sent to the host CPU that performs control management plane processing.

7 and 8, in the OAM frame processing apparatus according to an embodiment of the present invention, an OAM processing unit will be described. The OAM processing unit includes a RAPS processing unit and a RAPS exclusion frame processing unit.

A RAPS processing unit will be described with reference to FIG. 7. If the function identifier is a RAPS frame, the RAPS processing unit looks up the association information of the RAPS frame and associates the RAPS frame with the RAPS frame.

The RAPS node checker checks the source node and the destination node of the RAPS frame.

The RAPS frame processing unit looks up the information corresponding to the identifier of the RAPS frame and associates the information looked up in the RAPS frame and transmits it.

According to an embodiment of the present invention, the RAPS processing unit checks whether the RAPS ID of the MPLS-TP device is the same as the source node ID in the received RAPS frame, and if the RAPS ID is identical to the source node ID, the frame transmitted by the MPLS-TP device is received abnormally. If so, discard it. If it is not the same as the source node ID, it is checked whether it is the same as the destination node ID in the receiving RAPS frame. If it is the same as the destination node ID, a message for reporting the RAPS reception to the host CPU performing the control management plane processing is generated and forwarded. S401). If it is not the same as the destination node ID in the RAPS frame, information for looking up the database and forwarding the RAPS is obtained using the Input Port as a key. (S402) A message for reporting the RAPS reception to the control management plane processor is generated. The generated message is transferred and forwarded by changing the RAPS header with reference to the forwarding information (S403).

An RAPS exclusion frame processing unit will be described with reference to FIG. 8. If the function identifier is not a RAPS frame, the RAPS exclusion processing unit looks up the identifier of the OAM received frame and obtains and processes related information.

The OAM association information generator obtains information by looking up an identifier of the OAM received frame. The database is looked up according to the frame identifier to obtain related information.

The label checker determines whether the label of the OAM reception frame is exposed and determines whether to forward.

The RAPS exclusion frame processor performs frame processing preset according to the label checked by the label checker. Pre-set frame processing means that a process for transmitting to a non-real-time OAM processing unit if the function identifier is not CCM, a process for checking for connectivity defects if the function identifier is CCM, or a process for CCM recovery is previously set by the user. .

According to an embodiment of the present invention, the RAPS exclusion frame processor extracts MEL, OpCode, and Flag of the PDU common field for OAM frames other than RAPS, and extracts MEGID, MEPID, and LM Fields in the case of CCM. Look up the database (DB) with Input Port, MPLS Label (s) as a key to get MPLS Label (s) Operation, Expected Rx CCM Fields, Associated CCM Tx DB information (S501), and the result is that Pop (GAL) label is Pop ( Check whether the label before GAL or GAL is GAL exposed with Swap & TTL = 1 (MIP). (S502) If GAL is not exposed, data frame processing is performed for forwarding. (S503) GAL in MIP When exposed, it generates and forwards a message to report to the host CPU that the OAM frame has received. If the GAL is exposed in the MEP, check whether the OpCode is CCM (S504). If the OpCode is not CCM, generate and transmit a message for reporting to the host CPU that performs the OAM frame if the OpCode is CCM. If is CCM, check whether there is connectivity defect by comparing MEGID, MEPID, CCM Interval among Expected Rx CCM field value obtained through lookup and CCM field value extracted from received frame. (S505) If there is connectivity defect, control the defect item. Generates and delivers a message for reporting to the host CPU performing management plane processing. If there is no connectivity defect, check whether the check message is recovered by checking the state immediately before the CCM Watchdog Counter, which is a statistics counter for monitoring the received CCM (S506). Initialize and update the RDI field of the Associated CCM Tx DB to 0 to inform the other party (S507), and generate and deliver a message for reporting the CCM recovery to the host CPU performing the control management plane processing (S509). If it is not CCM recovery (before CCWatchdog Counter = TRUE), update the Associated CCM Tx DB to apply the LM Fields (RxFCb, TxFCb) obtained through the receiving CCM to the sending CCM, calculate the dual-ended loss measurement, In order to store the result, CCM terminates after updating the loss field of the CCM Rx DB (S508).

A method of processing an OAM frame in a packet delivery network according to an embodiment of the present invention will be described with reference to FIG. 9. An OAM frame processing method of an MPLS-TP-based packet delivery network may include a data plane processing step and a control management plane processing step. About the OAM frame processing method The same content as the above-mentioned OAM frame processing apparatus is replaced with the above-mentioned content.

The data plane processing step processes OAM frames requiring real time processing using a network processor, and the control management plane processing step controls settings of the data plane processing step using a general purpose processor, and the OAM does not require real time processing. Process the frame.

According to an embodiment of the present invention, the MPLS-TP OAM processing apparatus first checks whether an input frame is an interrupt frame. If the input frame is an interrupt frame, it checks the interrupt source, extracts a field for lookup in the case of RTC, and performs a transmission interrupt process for generating a CCM. In case of WD, it extracts the field for lookup and performs the interrupt interrupt to report the CCM link failure to the host and inform the other MEP.

If the input frame is not an interrupt frame, check the type of the input frame first because it is a transmit (Tx) or receive (Rx) frame. In case of Ethernet frame, data frame processing is performed. In the case of an MPLS frame, it checks whether the input frame is an OAM reception frame with a GAL, and performs OAM reception processing only in that case. If GAL is exposed during OAM reception processing, MEP / MIP processing is performed. If GAL is not exposed, data frame processing is performed for forwarding. Control frame related to L2 or L3 protocol is transferred to the control management plane processing unit to handle it.

Embodiments of the present invention can be written in a computer program. The code and code segments that make up this computer program can be easily deduced by a computer programmer in the field. In addition, the computer program is stored in a computer readable medium (Computer Readable Media), and the embodiment is implemented by being read and executed by a computer. The information storage medium includes a magnetic recording medium, an optical recording medium and a carrier wave medium.

The present invention has been described above with reference to preferred embodiments. It will be understood by those skilled in the art that the present invention may be embodied in various other forms without departing from the spirit or essential characteristics thereof. Therefore, the above-described embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is shown not in the above description but in the claims, and all differences within the scope should be construed as being included in the present invention.

Claims (1)

In the OAM frame processing apparatus of a packet delivery network,
A network OAM manager configured to select an OAM frame requiring real-time processing based on label information included in the received packet and manage a state of the selected OAM frame; And
An OAM frame processing apparatus including a non-real-time OAM processing unit for managing the state of the OAM frame that does not require real-time processing, and controls the setting of the network OAM management unit.

Images