KR102015111B1 - Apparatus and method of protection switching of packet in transport networks - Google Patents

Abstract

The present invention relates to a packet protection switching device and a method in a transmission network. The packet protection switching device according to an embodiment includes a data interface that receives a frame, and determines whether the received frame is a valid frame. A processor configured to check the type and generate an internal event message corresponding to the identified frame type, and a generator configured to generate at least one of a frame based on a protection switching protocol and a frame for changing a packet transmission path from the generated internal event message. The data interface unit transmits the generated frame to each packet processor in the line card.

Description

Packet protection switching device and method in transport network {APPARATUS AND METHOD OF PROTECTION SWITCHING OF PACKET IN TRANSPORT NETWORKS}

The present invention relates to an apparatus and a method for packet protection switching, and more particularly, to a technical concept of protecting a packet transmitted between transport network systems by rapidly changing a packet path by hardware control when a failure occurs in a transport network system.

There is a limit to the explosive increase in data traffic due to the popularization of the Internet and the integration of wired and wireless Internet, and the acceptance of high quality services such as IP-TV into the existing complex delivery network. This enables scalability using a variety of data link layers such as the Internet Engineering Task Force (IETF) multi-protocol label switching-transport profile (MPLS-TP) and IEEE backbone bridging-traffic engineering (PBB-TE). And a plan for a premium transmission service that provides a quality of service (QoS) between end-to-end.

In order to provide a high quality premium service, it must operate stably in the event of a failure of the packet transmission path or delivery network system in the packet delivery network to provide users with uninterrupted service. In addition, the efficiency of the network should be maximized. The methods to achieve this are protection switching and restoration.

Protection switching divides the paths between nodes into a working path and a protection path, and if there is no failure, it carries traffic to the working path and fails in the working path where the packets of the network are transmitted. When the packet transmission path is changed according to the control of the path, the path is switched from the working path to the protection path to transmit the packet to be transmitted to the protection path.

On the other hand, a recovery method is a method of restoring a suspended service to its original service state by using paths and resources available in the network after a network failure occurs.

In the conventional packet delivery network system, protection switching is performed by using a general-purpose processor, a packet processor mounted on a line card of a packet delivery network system, an automatic protection switching (APS) frame or APC, which is a protection switching protocol through communication between a host processor and an upper main processor. (Automatic Protection Coordination) frame and OAM (Operation, Administration and Maintenance) frame is processed to switch over the packet transmission path to overcome the failure. That is, in the conventional protection switching method, the failure of the packet transmission path and the transmission network system in the network is first recognized by the hardware-based packet processor. However, in order to protect the transmission path, the path failure signal is transmitted to the host processor mounted on the line card, and the host processor exchanges a protocol (APS or APC, OAM frame processing protocol) for protection switching with the upper main processor. As a result, software-based transmission path protection switching can be performed.

However, this method handles packet transfer path protection switching in software with relatively low speed based on the host processor and the main processor based on the packet transmission path according to the network configuration. In addition, in case of network failure, the number of connections that satisfy the path protection switching request time within 50 ms is limited to a maximum of several hundred. Therefore, continuity check and connectivity verification, which requires real time processing, may not be efficiently performed, and a large amount of packets may be lost depending on a specific failure situation, thereby degrading the performance of a packet delivery network system. have.

The packet protection switching apparatus according to an embodiment determines whether a data interface unit for receiving a frame, the received frame is a valid frame, and checks the frame type if the received frame is a valid frame, and outputs an internal event message corresponding to the identified frame type. A generating unit for generating at least one of a frame based on a protection switching protocol and a frame for changing a packet transmission path from the generated internal event message, wherein the data interface unit respectively generates the generated frame in a line card. Send to the packet processor.

The packet protection switching device according to an embodiment further includes a control interface unit that receives an operator command from a host processor of the line card.

According to an embodiment of the present disclosure, the processor determines a priority request by comparing priorities with previously stored persistent requests in consideration of the received operator command, and determines the determined highest priority request. ) To generate an internal event message.

The packet protection switching apparatus according to an embodiment includes a plurality of database tables, a database control unit for allocating a specific timeslot for each client based on the plurality of database tables, and manages the plurality of internal control signals and information. The apparatus further includes a control register configured to control reading and writing of the database tables.

According to an embodiment, the data interface unit receives at least one of an APC frame, a Loss of Continuity (LoC) / Clear Loss of Continuity (LoC) frame, and a Remote LoC / CLoC frame from a packet processor.

According to an embodiment, the processing unit may include: a parser configured to extract a field of the received frame to check a type of a received frame, and determine an output path based on the type of the checked frame, wherein the received frame is a LoC. (Loss of Continuity) / CLoC (Clear Loss of Continuity) frame in the case of receiving the frame received from the parser, the working path or protection of the APC process in which the received frame is operated on the local line card ( A protection path, and a LOC detection unit for converting the received frame into an internal event message when the working path or the protection path is operated in the local line card, the working path or the In the protection path, it is determined whether the current traffic is transmitted or received, and the converted internal event according to the determination result. A hold-off (HO) decision unit for determining whether to send a message, and a highest priority request are determined from the transmitted internal event message and an operator command transmitted from a host processor, and the determined highest priority request is determined. Considering this includes a local command request unit for generating an internal event message.

According to an embodiment, the LOC detection unit, when the received LoC / CLoC is a working path or a protection path operated on a line card other than the local line card, the received LoC / CLoC is a corresponding line. The generation unit is requested to generate a Remote LoC / CLoC frame for delivery to the card.

According to an embodiment, the HO (Hold-Off) determiner, when the internal event message is generated in the path that is currently transmitting and receiving the traffic (Working) or the protection (Protection) path, the internal event If the message is delayed for a predetermined time and then transmitted to the local command request unit, and the message is not generated in the current path of the working path or the protection path, the local command request without delay. Transfer to negative.

The processor may further include an APC detector configured to receive a frame received from the parser when the received frame is an APC frame or a Remote LoC / CLoC frame.

According to an embodiment, the APC detector may convert a Remote LoC / CLoC frame transmitted from another line card into an internal event message and transmit the internal event message to the HO (Hold-Off) determiner.

According to an embodiment, the APC detection unit receives mounting and dismounting information of a line card from software of a host processor, and looks up a working path set in the line card to include an internal event including a local LoC / CLoC signal for each APC-ID. Packet protection switching device that generates a message.

Packet protection switching device according to an embodiment further comprises an APC message receiving unit,

Extracting field information (REQ, FP, DP) and C-ID (Connection Identification) for the APC frame, and the APC message receiving unit extracts the extracted field information (REQ, FP, DP) and C-ID (Connection Identification). Create an internal event message.

According to an embodiment, the generation unit may determine a global top priority request in response to the internal event message and output at least one of an internal event message that is a global local command and an internal event message that is a global remote command based on the determination. A command request unit, a state transition control unit that receives the output internal event message, performs a state transition in consideration of an operator command, and looks up the TX frame structure table based on the state transitioned internal event message. And an APC message generating unit for requesting the data interface to encode the APC frame according to the lookup result and to send it to the packet processor of the corresponding line card.

The packet protection switching device according to an embodiment further includes a remote LoC and SetBS generation unit, the remote LoC and SetBS generation unit refers to a lookup result and generates a remote LoC / CLoC frame based on the lookup result referred to above, And requesting a data interface to transmit the generated remote LoC / CLoC frame to another line card of the same local packet delivery system.

The packet protection switching device according to an embodiment further includes a remote LoC and SetBS generation unit, the remote LoC and SetBS generation unit, analyzes the internal event message transitioned to the state, and generates a SetBS frame with reference to a look-up result, The data interface is requested to transmit the generated SetBS frame to each packet processor in a single line card or multiple line cards, and the packet processor receiving the SetBS frame performs transmission path protection switching.

In a packet protection switching method according to an exemplary embodiment, the method of receiving a frame from a packet processor of a line card in a data interface unit may determine whether the received frame is a valid frame, and if it is a valid frame, determine a frame type. Generating an internal event message corresponding to the identified frame type, and in the generating unit, generating at least one of a frame based on a protection switching protocol and a frame for changing a packet transmission path from the generated internal event message; And transmitting, by the data interface unit, the generated frame to each packet processor in a line card.

The packet protection switching method may further include receiving, by a control interface unit, an operator command from a host processor of the line card. The generating of the internal event message may include: Determining a priority request by comparing priorities with previously stored persistent requests in consideration of an operator command, and generating an internal event message in consideration of the determined highest priority request. It may include the step.

The generating of at least one of a frame based on the protection switching protocol and a frame for changing a packet transmission path may include determining a global top priority request in response to the internal event message, based on the determination. Outputting at least one of an internal event message that is a global local command and an internal event message that is a global remote command, receiving the output internal event message, and performing a state transition in consideration of an operator command, wherein the state transition Looking up a TX frame structure table based on an internal event message, and requesting a data interface to encode an APC frame and send it to a packet processor of a corresponding line card according to the lookup result. .

The generating of at least one of a frame based on the protection switching protocol and a frame for changing a packet transmission path may include generating a remote LoC / CLoC frame based on the referenced lookup result, and generating Requesting the data interface to send one remote LoC / CLoC frame to another line card in the same local packet delivery system.

Generating at least one of a frame based on the protection switching protocol and a frame for changing a packet transmission path according to an embodiment may include analyzing the state transitioned internal event message and generating a SetBS frame with reference to a lookup result. And requesting a data interface to transmit the generated SetBS frame to each packet processor in a single line card or a plurality of line cards, wherein the packet processor receiving the SetBS frame is protected by a transmission path. Perform the transfer.

According to the present invention, when a failure occurs in a packet delivery network, an increase in the number of protection switching connections managed in connection with a packet transmission path and protection switching for a fast and stable packet transmission path can be performed.

According to the present invention, by processing the packet transmission path protection switching on a hardware basis, it is possible to quickly process the path protection switching for the transmission path change in the packet processor, thereby reducing the loss of transmitted packets.

1 is a diagram illustrating a line card of a packet delivery system to which a packet protection switching device according to an embodiment is applied.
2 is a block diagram illustrating a packet protection switching device according to an embodiment.
3 is a block diagram illustrating in more detail a packet protection switching apparatus according to an embodiment.
4 is a diagram illustrating an internal event transmission message structure for a packet protection switching device according to an embodiment.
5 is a diagram illustrating a structure of a database controller used in a packet protection switching device according to an embodiment.
FIG. 6 illustrates a structure of a priority table used in a packet protection switching device according to an embodiment.
7 is a diagram illustrating a global command request unit of a packet protection switching device according to an embodiment.
8 is a diagram illustrating a state transition controller of a packet protection switching device according to an embodiment.
9A to 9B are diagrams illustrating a packet protection switching method according to an embodiment.
10A and 10B are diagrams illustrating a method of operating a global command request unit of a packet protection switching device according to an embodiment.
11A to 11B are diagrams illustrating a method of operating a state transition controller of a packet protection switching device according to an embodiment.
12A to 12C are diagrams illustrating an operation method of an APC message generator of a packet protection switching device according to an embodiment.
13 is a diagram illustrating a method of operating a Remote LoC and SetBS generator of a packet protection switching device according to an embodiment.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terminology used herein is a term used to properly express a preferred embodiment of the present invention, which may vary according to a user, an operator's intention, or a custom in the field to which the present invention belongs. Therefore, the definitions of the terms should be made based on the contents throughout the specification. Like reference numerals in the drawings denote like elements.

1 is a diagram illustrating a line card 100 of a packet delivery system to which a packet protection switching device 120 is applied, according to an exemplary embodiment.

A packet delivery system in a delivery network includes a plurality of line cards, a plurality of switch fabrics that provide packet delivery switching within the packet delivery system, and a main processor that controls the packet delivery system. In addition, the packet delivery system transmits and receives data packets between packet delivery systems in a delivery network through a plurality of line cards.

The line card 100 according to an embodiment is a packet protection switching to control the path protection switching of the packet delivery system together with the host processor 110 for controlling the line card 100, the packet processor 130 for performing packet processing. Device 120.

The packet protection switching device 120 may perform protection switching on a hardware basis when a failure occurs on a packet transmission path or a packet delivery network system in a protection group grouped into a working path and a protection path. That is, the packet protection switching device 120 may reduce the packet loss and stabilize the transmission network system by quickly processing the path management for transport packet recovery and the path switching to the protection path accordingly.

2 is a block diagram illustrating a packet protection switching apparatus 200 according to an embodiment.

In order to reduce packet loss and stabilize the transmission network system, the packet protection switching apparatus 200 according to an embodiment analyzes an input frame and generates and outputs a frame based on a protection switching protocol or a frame for changing a packet transmission path. can do.

To this end, the packet protection switching device 200 according to an embodiment may include a data interface unit 210, a processing unit 220, a control interface unit 230, and a generation unit 240.

The data interface unit 210 according to an embodiment receives a frame from a packet processor of a line card.

In detail, the data interface unit 210 receives at least one of an APC frame, a Loss of Continuity (LoC) / Clear Loss of Continuity (LoC) frame, and a Remote LoC / CLoC frame from the packet processor to be transmitted to the processor 220. Can be.

The processor 220 according to an embodiment determines whether the received frame is a valid frame, and if it is a valid frame, checks the frame type and generates an internal event message corresponding to the identified frame type.

For example, the processor 220 may extract a field of the received frame to check the type of the received frame and determine an output path based on the type of the identified frame. Also, when the received frame is a Loss of Continuity (LoC) / Clear Loss of Continuity (CLoC) frame, the received frame is received, and a working frame of an APC process in which the received frame is operated on a local line card. It can be determined whether it is a path or a protection path. If the received frame is a working path or a protection path operated by the local line card, the processor 220 may directly convert the received frame into an internal event message. If the received frame is a working path or protection path that is operated on a line card other than the local line card, another component may be created to generate a new frame for delivering the received frame to the line card. You can request

In addition, the processor 220 may further determine whether an event message is generated in a path that is currently transmitting and receiving traffic in a working path or a protection path. The processor 220 may determine whether to transmit the converted internal event message according to the determination result, and determine a highest priority request from the transmitted internal event message and an operator command transmitted from the host processor. In addition, the processor 220 may generate an internal event message in consideration of the determined highest priority request.

When the internal event message is generated in a working path or a path that is currently transmitting or receiving traffic among the protection paths, the processor 220 delays the internal event message for a predetermined time and then generates I can deliver it. On the other hand, if the internal event message is not generated in the path that is currently transmitting and receiving traffic in the working path or the protection path, the processor 220 may transmit to the generation unit without delay.

The case where the frame received by the processor 220 is an APC frame or a Remote LoC / CLoC frame may be considered. In this case, the processor 220 receives the mounting and dismounting information of the line card from the software of the host processor, looks up the working path set in the line card, and generates an internal event message including a local LoC / CLoC signal for each APC-ID. You can also create

In addition, the processor 220 extracts field information (REQ, FP, DP) and C-ID (Connection Identification) for the APC frame, extracts the extracted field information (REQ, FP, DP) and C-ID (Connection Identification). You can also generate an internal event message based on).

The generation unit 240 generates at least one of a frame based on a protection switching protocol and a frame for changing a packet transmission path from the generated internal event message. At this time, the data interface unit 210 may transmit the generated frame to each packet processor in the line card.

The generation unit 240 according to an embodiment may determine the global top priority request in response to the received internal event message. In addition, the generation unit 240 according to an embodiment may output any one of the internal event message of the internal event message of the global local command and the internal event message of the global remote command based on the determination of the global top priority request. In addition, the generation unit 240 according to an embodiment may receive an output internal event message, and may perform a state transition in consideration of an operator command. Accordingly, the generation unit 240 may look up the TX frame table based on the state transitioned internal event message, and may encode the APC frame according to the lookup result. In addition, the data interface 210 may be requested to send the encoded APC frame to the packet processor of the corresponding line card.

The generation unit 240 according to an embodiment may refer to the lookup result and generate a remote LoC / CLoC frame based on the referenced lookup result. In this case, the data interface 210 may be requested to transmit the generated remote LoC / CLoC frame to another line card of the same local packet delivery system.

The generation unit 240 according to an embodiment may analyze a state transitioned internal event message and generate a SetBS frame with reference to a lookup result. In this case, the generation unit 240 may request the data interface 210 to transmit the generated SetBS frame to each packet processor in a single line card or a plurality of line cards. The packet processor in the line card that receives the SetBS frame may perform transmission path protection switching.

The control interface 230 according to an embodiment may receive an operator command from the host processor of the line card. At this time, the processor 220 determines a priority request by comparing priorities with previously stored persistent requests in consideration of the received operator command, and considers the determined highest priority request. To generate an internal event message.

3 is a block diagram illustrating in more detail the packet protection switching apparatus 300 according to an embodiment.

The packet protection switching device 300 according to an embodiment may include a data interface unit 310, a processor 320, a control interface 330, and a generator 340.

In particular, the processor 320 according to an embodiment includes a parser 321, a loss of continuity detector 322, a hold-off decision block 323, and a local command. A request unit may include a local command request block 324, an automatic protection coordination (APC) detector 325, and an APC message receiver 326.

The parsing unit 321 may receive an APC frame, a Loss of Continuity (LoC) / Clear Loss of Continuity (LOC) frame, or a Remote LoC / CLoC frame from the packet processor via the data interface unit 310. . In addition, the parser 321 extracts a field of the received APC frame or LoC / CLoC frame or Remote LoC / CLoC frame, and transfers the field to the LoC detector 322 in the case of a LoC / CLoC frame, and transmits the APC frame or Remote LoC / CLoC. If the frame is transmitted to the APC detector 325. In this case, the fields used by the parser 321 are used to classify the frame for classification into a header type (HT) field and an extension (EXT) field (HT: 1, EXT), which are fields of an internal header of a received frame. : 3-> LoC / CLoC frame, HT: 0-> Remote LoC / CLoC frame, HT: 1, EXT: 1-> APC frame), RFC6378, RFC7271 channel type (0x0024), REQ (Request) , PT (Protection Type), R (Revertive), FP (Fault Path), DP (Data Path) value and the like.

The fields of the RFC standard described above are well-known technologies, and thus detailed descriptions thereof will be omitted.

When the LoC / CLoC frame is transmitted, the LoC detector 322 may convert the LoC / CLoC frame into an internal event message using C-ID information extracted from the parser 321. In one example, the connection identification (C-ID) information may be interpreted as maintenance entity group end point index (MEP-ID) information generated by the packet processor.

For example, the LoC detector 322 refers to the static memory structure table of the DB control unit 360, so that a working path or protection of an APC process in which an input frame is operated on a local line card. If the path corresponds to a protection path, C-ID information extracted into an internal event message may be converted.

The LoC detector 322 transmits a signal to a Hold-Off (HO) decision block 323 and, when handled by an APC process operated on another line card, converts the internal event message to generate a Remote LoC and SetBS. Transfer to section 345.

The HO determiner 323 transmits / receives current traffic in a working path or a protection path by information of an internal event message 403 including LoC / CLoC frame information received from the LoC detector 322. When it occurs in the path (Active Transport Entity), it functions to delay the internal event message without passing the internal command message to the local command request unit 324 for as long as the HO (Hold-off) timer value of the APC-ID. If LoC / CLoC is generated in a path that is not currently transmitting and receiving traffic (Standby transport entity), the internal event message is delivered directly to the local command requesting unit 324.

The local command requesting unit 324 receives the internal event message 403 received from the HO determining unit 323 and the operator command input through the control interface unit 330. Persistent Local REQ (Request) The priority is determined by comparing the priority with the persistent requests in the table.

In case of input for persistent requests such as Signal Fail (SF) or Signal Degrade (SD), the DB controller 360 can update the PI (Path Information) Table to Yes for LoC and No for CLoC. have.

At this time, the inputs for persistent requests are SF-W (Signal Fail working path), SF-P (Signal Fail protection path), SD-W (Signal Degrade working path), SD-P (Signal Degrade protection path), Clear Can be interpreted as SF-W, Clear SF-P, Clear SD-W, and Clear SD-P.

In addition, the DB control unit 360 may update the High Persistent Local REQ Table. The localOC command table of the DB controller 360 may be interpreted to store a currently valid operator command. In addition, the localOC (Local Operator Command) table may update the localOC table with a new value by the local command request unit 324 when a higher priority local request is input.

If the new top-level local request is a persistent request, the local command request unit 324 may set the localOC table to None and inform the SW (SoftWare) of the host processor that the local operator command has been deleted.

If the freeze table is Yes, the local command requester 324 may perform only a function of discarding the input local request without performing any operation other than updating the persistent request variables. In addition, the local command requester 324 prioritizes the input local request, updates related tables, and transmits an internal event message to the global command requester 341.

The APC detection unit 325 is divided into three functions, and converts the Remote LoC / CLoC frame input from the external line card through the parsing unit 321 into an internal event message, and delivers it to the HO determination unit 323. Can be done.

The APC detector 325 may receive the mounting and dismounting information of the line card in the packet delivery system from the SW of the host processor and look up the working path set in the line card from the Working LC Table of the DB controller 360. In this case, the APC detector 325 may generate an internal event message including a local LoC / CLoC signal for each APC-ID.

In addition, the APC detector 325 extracts field information (REQ, FP, DP) and C-ID (Connection Identification) for the APC frame input through the parser 321 and transmits it to the APC message receiver 326. Function

The APC message receiver 326 may find a corresponding APC-ID value by referring to a target LC (LineCard) table of the DB controller 360 using the C-ID extracted from the APC detector 325. In addition, the APC message receiver 326 may update the REQ, FP, and DP field values of all received APC messages to the APC message receiver (AMR) table of the DB controller 360. In addition, the APC message receiving unit 326 generates an internal event message and delivers it to the global command requesting unit 341. If the corresponding APC-ID is freezeed with reference to the freeze table of the DB controller 360, only the AMR table can be updated and the message can be discarded without any other operation.

The control register unit 350 manages internal control signals and information of the packet protection switching device 300, and controls read / write operations on all tables of the DB control unit 360.

The control interface 330 transmits and receives control data to and from the host processor, and provides a function of communicating with software (SW: Software) that is mounted in the host processor to support transmission path protection switching. In detail, the control interface unit 330 may include a physical interface such as a local bus or PCI-E (PCI-Express) as a CPU interface.

The data interface 310 may transmit and receive a packet processor, LoC / CLoC, Remote LoC / CLoC, APC frame, SetBS frame, and the like. To this end, the data interface unit 310 may include a physical interface such as GbE / SGMII / 10GbE.

The DB control unit 360 may include a plurality of DB tables. For example, the DB control unit 360 may include a Local OC Table, a High Persistent Local REQ Table, a MI Table (Management Information Table), a PI Table (Path Information Table), an AMR Table, a Hold-Off Running Table, and a HO Timer. Dynamic Memory Structure Block and Target LC (LineCard) such as Enable table, Misrunning table, Active Path Signal Degrade (SD) table, State DB (DataBase) table, Wait-To-Restore (WTR) running table Static Memory Structure Blocks may be included such as tables, working LC tables, revertive tables, aggregation tables, target user network interface (UN) tables, layer 2 destination address (L2 DA) tables, and remote L2 DA tables. have. The DB controller 360 may allocate a specific timeslot for each client as a method of controlling access to various DBs.

According to an embodiment, the generation unit 340 may include a global command request block 341, a state transition control block 342, and an APC message generation block 343. , A Remote LoC and a Set Bridge / Selector (SetBS) generator 340, and a TX Frame Table 290.

The global command requester 341 may determine the global top priority request from the internal event message 404 input from the local command requester 324 and the internal event message input from the APC message receiver 326. In addition, the global command request unit 341 may transmit an internal event message, which is a global local command, to the state transition control unit 342 when the global top priority request is determined as an input of the local command request unit 324 when determining the priority. . At this time, if the global top priority request is determined as a remote input from the APC message receiving unit 326, the global command requesting unit 341 transmits an internal event message which is a global remote command to the state transition control unit 342.

The state transition control unit 342 may include a local request state machine, a remote request state machine, and a complex request state machine. When an internal event message of Global Local is input, the state transition controller 342 may perform a state transition according to Operator Clear among Operator Commands.

On the other hand, the state transition control unit 342 may perform a state transition according to the Local Request State Machine when it is not SFDc (Clear Signal Fail or Degrade).

When an internal event message is input and Operator Clear or SFDc is among Operator Commands, the state transition control unit 342 may reevaluate the priority according to the Complex Request State Machine to perform the final state transition. In addition, when an internal event message that is a global remote is input, state transition may be performed according to a remote request state machine.

The APC message generator 343 may look up the TX frame structure table 344 by analyzing the internal event message input from the state transition controller 342. The APC message generator 343 may encode the internal event message as an APC frame as a lookup result and transmit the encoded APC message to a packet processor of a corresponding line card of a local packet delivery system. Accordingly, the packet processor may transmit the APC frame to the remote packet delivery system.

When transmitting APC frame, the packet processor transmits three times in succession for each APC within 3.3msec, and then periodically transmits the same APC frame every 5 sec until a new internal event message for the same APC-ID is input. have.

The Remote LoC and SetBS generator 345 may analyze the internal event message received from the LoC detector 322.

Accordingly, the Remote LoC and SetBS generator 345 may generate a Remote LoC / CLoC frame with reference to the lookup result of the Remote L2 DA Table. In addition, the generated Remote LoC / CLoC frame can be transmitted to another line card of the same local packet delivery system.

The Remote LoC and SetBS generator 345 analyzes the internal event message received from the state transition controller 342 and references the lookup results of the target UNI table, the L2 DA table, and the aggregation table of the DB controller 360. Can be. As a result of reference, the Remote LoC and SetBS generator 345 generates a SetBS frame, and transmits the SetBS frame generated by each packet processor in a single line card or a plurality of line cards with a bridge and a selector so that the packet processor transmits the set path. Ensure protection transfers.

The TX frame structure table 344 includes L2 header information of a frame format such as Ethernet, MPLS-TP, or PW (Pseudo-Wire) according to a transport network interface in a packet delivery system. In addition, the TX frame structure table 344 may be set to static via a local bus or PCI-E. In addition, the TX frame structure table 344 stores the information necessary for the APC message generator 343 and the Remote LoC and SetBS generator 345 to perform frame generation.

The packet protection switching device 300 according to FIG. 3 may receive a local LoC / CLoC frame or an APC frame according to a path failure between the host processor and the packet processor. Further, based on the received frame, the SetBS frame instructing a protection transfer command may be transmitted to a packet processor on a line card of the same packet delivery network system, or an APC frame may be transmitted to another packet delivery network system.

That is, the protection switching by the packet protection switching device 300 is a protection switching in a packet processor of a line card that is physically connected to each other between packet delivery systems that transmit data packets (for example, MPLS-TP, PW, Carrier Ethernet, etc.). It may be performed by receiving a SetBS frame indicating a command.

Thus, using the packet protection switching device 300 may be a path protection switching for the data packet between a plurality of packet delivery systems in the transport network (Transport Network).

4 is a diagram illustrating an internal event transmission message structure for a packet protection switching device according to an embodiment.

Reference numeral 401 may be interpreted as an internal event message used by the LoC detector through the parser. Reference numeral 402 may be interpreted as an internal event message transmitted to the Remote LoC and SetBS generation unit via the LoC detection unit when the destination line card does not match the local line card by looking up the target LC table.

In addition, reference numeral 403 denotes an internal event message transmitted to a HO determiner via a LoC detector, a Remote LoC / CLoC input to the HO determiner via an APC detector, or a local command requester 324 via a HO determiner. Can be interpreted as

Reference numeral 404 may be interpreted as an internal event message transmitted from the local command request unit to the global command request unit 341, and reference numeral 405 may be interpreted as an internal event message transmitted from the APC message receiver to the global command request unit. .

Reference numerals 406 to 407 show internal event messages transmitted from the global command request unit 341 to the state transition control unit 342, and reference numeral 408 from the state transition control unit 342 to the APC message generation unit 343. , 409 shows an internal event message transmitted to the Remote LoC and SetBS generator 345.

As shown in FIG. 4, the message information includes an L / CL flag bit indicating whether a LoC or a CLoC, a connection identification (C-ID) indicating a maintenance entity group end point (MEP) information generated by a packet processor in a line card, and a destination. DLN (Destination Linecard Number) bit indicating line card number, Source Linecard Number (SLN) bit indicating source line card number, APC-ID (APC Identification) indicating APC processor information in line card, working path Combining W / P Flag bit indicating Protection Path, Request, Fault Path and Data Path according to APC standard, new Priority information used in packet protection switching device, and interworking with SW in host processor. EVENT, EXT flag bits, REQ (Request), FP (Fault Path), and Data Path (DP) flag bits, globally used for APC frames in the RFC6378 and RFC7271 standards. Global Local (GL) bit indicating that Global Local is selected in the command request unit 341, and Highest Persistent indicating the value provided in the Highest Persistent Local REQ (Request) Table of the dynamic memory structure block in the DB control unit 360. Local Request (Global Remote) flag bit, GR (Global Remote) bit indicating that Global Remote is selected in global command request unit 341, Generate APC (GA) bit instructing generation of APC frame generated from state transition control unit 342, R (Revertive) bit to indicate whether it is in Revertive mode or non-Revertive mode, Generate SetBS (GS) bit to indicate generation of SetBS frame generated from state transition control unit 342, and Signal Degrade (SD) at local or remote It includes a SDI (Signal Degrade Indication) bit set at the time.

In FIG. 4, the C-ID and the APC-ID are represented by 13 bits, but the C-ID and APC-ID are not limited to 13 bits.

FIG. 5 is a diagram illustrating a structure of a database controller 500 used in a packet protection switching device according to an embodiment.

Reference numeral 510 denotes a dynamic memory structure block of the packet protection switching device. Reference numeral 530 denotes a static memory structure block.

The table in dynamic memory structure block 510 is as follows.

Local Operator Command (OC) Table (511) defines None / LO (Lock-Out) / Forced Switch (FS) / Manual Switch Working Path (MS-W) / Manual Switch Protection Path (MS-P) / EXER (Exercise) values are stored, and the Highest Persistent Local REQ (Request) Table (512) is the Signal Fail Protection Path (SF-P) / Signal Fail Working Path (SF-W) / Signal Degrade Working Path (SD-W). Only persistent local requests such as / SD-P (Signal Degrade Protection Path) / NR (No Request) are stored. The PI (Path Information) Table 513 inputs persistent requests such as SF or SD, namely SF-W, SF-P, SD-W, SD-P, Clear SF-W, Clear SF-P, Clear. Updated at SD-W, Clear SD-P input.

The HO (Hold-Off) Running Table (514) indicates that the HO timer for the APC-ID is running, and the HO (Hold-Off) Timer Enable Table (515) indicates that the APC-ID enables the HO timer. Stores information about whether to do so. The freeze table 516 stores freeze information that prevents the local command requesting unit 324 from taking any action other than updating the persistent request variables in the PI table 513.

APC Message Receiver (AMR) Table 517 The APC detector 325 updates and stores the request value, fault path, and data path values extracted from the received APC frame. MI (Management Information) Table (518) is a table indicating that a protection switching request can be accepted for the APC-ID. This operation is only available when Yes, and when No, a request for the APC-ID is entered. Destroy and service the next request.

The Misrunning Table 519 indicates that the Mismatch timer for the corresponding APC-ID is running.

Active Path SD (Signal Degrade) Table 520 records the active path at the time of local SD generation and stores information for simultaneous SD priority resolution when remote SD is input later.

The State DB (DataBase) Table 521 stores a current state of the state transition control unit 342 and a DP value when generating and transmitting an APC frame.

The tables in the static memory structure block 530 include Local Operator Command (OC) Table (511), Highest Persistent Local REQ (Request) Table (512), Path Information (Table) 513, and Hold-Off (HO). Running Table (514), HO (Hold-Off) Timer Enable Table (515), Freeze Table (516), APC Message Receiver (AMR) Table (517), Management Information (MI) Table (518), Misrunning Table (519) ), An Active Path SD (Signal Degrade) Table 520, a State DB (DataBase) Table 521, and a WTR Running Table 522.

In detail, the R (Revertive) Table 531 stores information on whether the corresponding APC-ID performs protection switching in a revertive mode or a non-revertive mode. The Remote L (Layer) 2 DA (Destination Address) Table 532 stores information on the destination address referenced when generating a Remote LoC / CLoC frame. The Working LC (LineCard) Table 533 stores mounting and dismounting information of the line card of the packet delivery system. The Target LC (LineCard) Table 534 stores an APC-ID, a Working / Protection Path (W / P), and a Destination Linecard Number for the C-ID information of the received frame. The L (Layer) 2 Destination Addres (DA) Table 535 stores information about a destination address that is referenced when a SetBS frame is generated. A target UNI (User Network Interface) table 536 stores line card bitmaps for destination UNIs used in the aggregation table 537 to transmit SetBS frames. The Aggregation LC (LineCard) Table 537 is a table that sets the traffic ID (identification) of the line card with the bridge / selector of the protected traffic, and stores the traffic ID value. That is, the table in the static memory structure block 530 shows that each UNI has aggregated a plurality of connections (eg, PWs (Pseudo-Wires)) across a plurality of User Network Interface (UN) line cards. Stores the traffic ID value referenced when creating a SetBS (Set Bridge / Selector) frame with a line card.

The LoC Converter Table 538 stores information for converting an internal event message when a destination address is mapped when a remote LoC / CLoC frame is input.

FIG. 6 is a diagram illustrating a structure of a priority table used in a packet protection switching device according to an embodiment.

Reference numeral 610 denotes a Request and Fault Path value according to each instruction in the priority and APC frames used in the RFC7271 standard. Reference numeral 620 may map the Request and Fault Path values according to the respective commands of the APC frame with the EVENT and EXT values used internally by the packet protection switching device. In addition, reference numeral 620 shows a value used in SW of the host processor for an operator command.

7 is a diagram illustrating a global command request unit 700 of a packet protection switching device according to an embodiment.

As illustrated in FIG. 7, the global command request unit 700 may generate an internal event message 404 to 405 transmitted from the local command request unit and the APC message receiver to generate a Global Top Priority Request.

When the internal event messages 404 and 405 are input, the Global Request Holding Tank 701 may store this message information.

In addition, the Request Selection Block 702 may look up the AMR Table, Local OC Table, and Highest Persistent Local REQ Table of the DB control unit when the internal event message 404 is input from the local command request unit. In addition, the Request Selection Block 702 may look up the Local OC Table 511 and the Highest Persistent Local REQ Table 512 when the internal event message 405 is input from the APC message receiver.

The Request Conversion Block A 703 may look up the AMR Table and convert the result into EVENT and EXT values to check the internal priority of the packet protection switching device.

The Request Conversion Block B 704 may convert the internal REQ and FP field values into EVENT and EXT values to check the internal priority of the packet protection switching device when the internal event message 405 is input.

The Equal Priority Check Block 705 may be converted from the Request Conversion Block A 703 and the Request Conversion Block B 704 to compare priorities including the Equal Priority.

The counter block 706 stores the input and output statistical information of the global local command unit, and generates an internal event message 406 when the Global Top Priority Request is local when the internal local message messages 404 to 405 are input. send.

The global remote command generation block 708 may generate and transmit an internal event message 407 if the global top priority request is remote when the internal event messages 404 to 405 are input.

In addition, the Global Remote Command Generation Block 708 is a txDP for the corresponding APC-ID of the State DB Table, which is a dynamic memory structure block of the DB controller, when the EVENT and EXT values of the internal event message 404 are SD-P or SD-W. (Data Path for Transmission) value can be transmitted. At this time, the Global Remote Command Generation Block 708 may transmit a final APC frame due to Local SD-X (Local SD-W or Local SD-P) and update the Active Path SD Table. At this time, the Active Path SD Table includes simultaneous SD priority resolution that determines which one has a higher priority when the Remote SD-X having a different X value is input (Remote SD-W and Remote SD-P). can do.

8 is a diagram illustrating a state transition controller 800 of a packet protection switching device according to an embodiment.

As illustrated in FIG. 8, the state transition controller 800 may receive an internal event message 406 through 407 from the global command requester and update the current state through the corresponding state transition state machine. At this time, the state transition controller 800 may transmit the internal event message 408 to the APC message generator and the internal event message 409 to the Remote LoC and SetBS generator.

To this end, the state transition control unit 800 includes a state transition holding tank 801, a request conversion block 802, an event conversion block 803, a wtr queue 804, a counter block 805, a state transition control block 806. ), A WTR control block 807, a Local Request State Machine 808, a Complex Request State Machine 809, a Remote Request State Machine 810, and a Request Output Selection Block 811.

First, the State Transition Holding Tank 801 stores this message information when the internal event messages 406 to 407 are input.

The Request Conversion Block 802 converts the result of the AMR Table 517 lookup of the DB control unit into internal EVENT and EXT values of the packet protection switching device.

The Event Conversion Block 803 converts the HPLR from the message fields of the internal event messages 406 to 407 into REQ, FP, and DP values of the APC frame.

The counter block 805 stores the input and output statistical information of the state transition controller, and the state transition control block 806 analyzes the input internal event message information and transmits it to the corresponding state machine.

The Local Request State Machine 808 controls the state transition when an internal event message 406 is input and is not Operator Clear or SFDc.

The Complex Request State Machine 809 controls the state transition when the input internal event message is Operator Clear or SFDc.

The remote request state machine 810 may control the state transition when the input internal event message 407 is input.

The WTR control block 807 may control a Wait To Restore (WTR) operated by the SW, and change the operation to Start WTR or Stop WTR according to the corresponding APC-ID. In addition, the WTR control block 807 updates the WTR Running Table when a WTR Timer Expiry signal having an EVENT value of 5 is input.

The WTR Queue 804 stores the generated Start / Stop WTR control signal for transmission to the SW of the host processor. In addition, the Request Output Selection Block 811 may select an output of the Local Request State Machine 808, the Complex Request State Machine 809, and the Remote Request State Machine 810 to generate internal event messages 408 to 409.

The local request state machine 808, the complex request state machine 809, and the remote request state machine 810 may perform state transition using current state information on the corresponding APC-ID of the state DB table. After the transition, the State DB Table for the APC-ID is updated.

9A to 9B are diagrams illustrating a packet protection switching method according to an embodiment.

In the packet protection switching method according to an embodiment, when receiving a frame through the data interface unit 910, it may check whether a valid frame is valid (911). If the check result is not a valid frame, the packet protection switching method discards the frame, and if it is a valid frame, checks whether the local LoC / CLoC is 912. In addition, in the packet protection switching method according to an embodiment, if the received frame is a local LoC / CLoC from step 912, the packet protection switching method is stored in the LoC / CLoC queue (913), and after looking up the target LC table (534) of the DB controller (914). In operation 915, it may be checked whether a destination linecard number (DLM) matches the received frame.

In the packet protection switching method according to an embodiment of the present invention, if a DLM (Destination Linecard Number) does not match the received frame as a result of the check (915), a remote LoC / CLoC frame generation command is generated (916) and transferred to step 3 of FIG. .

If the result of the check 912 is that the received frame is not the local LoC / CLoC, it is stored in the APC queue (917), and from step 917 it is checked whether the output is a remote LoC / CLoC frame (918). As a result of the check 918, if the received frame is a Remote LoC / CLoC frame, it may be checked 919 whether the DLM is matched.

As a result of the check 919, if the received frame does not match, discard (920). If the result of the check 919 is matched, the LoC Converter table 538 is looked up 921.

The packet protection switching method according to an embodiment may receive an internal event message 403 from the case where the DLMs of steps 921 to 915 match, and check the hold-off timer information in the HO determiner (922). Accordingly, the packet protection switching method according to an embodiment updates a local request priority check 923 and a table of the corresponding dynamic memory structure block (924). The packet protection switching method according to an embodiment generates an internal event message 404 and sends it to step 1 of FIG. 10A.

The packet protection switching method according to an embodiment checks 926 whether it is an APC frame if it is not a remote LoC / CLoC frame. In operation 926, if the result is not an APC frame, the current process is discarded.

According to an exemplary embodiment, the packet protection switching method discards a process when the received frame is a provision mismatch, or checks 928 tables of corresponding dynamic memory structure blocks of the DB controller.

In the packet protection switching method according to an exemplary embodiment, if the corresponding information needs to be transmitted to the host processor SW from steps 923 and 928, the packet protection switching method transmits the corresponding information (929). In the packet protection switching method according to an embodiment, after updating the tables of the corresponding dynamic memory structure block (930), the freeze table (516) of the DB controller is checked (931).

As a result of checking 931, if it is determined that the freeze table is enabled in the case of freeze, if the process is discarded and disabled, the internal event message 405 is generated (932), and step 1 of FIG. 10A is performed. Send to.

10A and 10B are diagrams illustrating a method of operating a global command request unit of a packet protection switching device according to an embodiment.

The operation method of the global command request unit according to an embodiment may store 1010 internal event messages 404 to 405 inputted from step 1 of FIG. 9 in a global request queue. In addition, the operation method of the global command request unit according to an embodiment checks whether it is a local command request (1011), and in case of a local command request, a Local OC Table 511, a Highest Persistent Local REQ Table 512, and an AMR Table 517. Lookup 1012. In addition, according to an embodiment of the present disclosure, in operation 1013, the result of looking up the AMR Table 517 is changed to EVENT and EXT values to check an internal priority order. Checking the priority of the lookup result at 511 to 512 and the value converted in step 1013 generates an internal event message 406 when the lookup result at 511 to 512 is greater than the conversion value in step 1013 (1015). And step 2 of FIG. 11A.

According to an embodiment of the present disclosure, in operation 1014, if the lookup result is not greater than the conversion value of step 1013, the Equal Priority is checked (1016), and if the lookup result is not equal to Equal Priority in step 1016, an internal event message 407 is generated. 1023, and transmits to step 2 of FIG. 11A. According to an exemplary embodiment of the present invention, in operation 1016, if the EVENT and EXT values are the same in step 1016, the global command request unit checks whether the EVENT and EXT values are the same, and generates an internal event message 406 in step 1015 to step 2 of FIG. 11A. send.

If it is not the same in step 1017, the operation method of the global command request unit according to an embodiment checks whether the look-up result of the Local OC table 511 is MS-X (MS-W or MS-P) (1018). If the result of the check 1018 is that the lookup result is MS-X, an internal event message 407 is generated 1023 and transmitted to step 2 of FIG. 11A. If the lookup result is not MS-X, the Active Path SD Table 520 is looked up 1027.

According to an embodiment, in operation 1011, if it is not a local command request, the method for operating a global command request unit checks whether it is a remote command request. If the input request is not a remote command request, the process discards and if it is correct, the local OC table 511 and the high persistent local REQ table 512 are looked up 1020.

In the operation method of the global command request unit according to an embodiment, since the received message is an internal event message 405 which is a remote command request, the method converts REQ, FP, and DP into EVENT and EXT values. Also, in operation 1021, the method of operating the global command request unit checks whether the value converted in step 1021 is greater than the lookup result. If the result of check 1022 is large, an internal event message 407 is generated 1023 and transmitted to step 2 of FIG. 11A.

According to an embodiment, in operation 1022, when the global command request unit is not larger than the lookup result, an Equal priority check 1024 is performed. If the result of the check 1024 is not equal to Equal Priority, an internal event message 406 is generated 1015 and transmitted to step 2 of FIG. 11A.

According to an embodiment of the present disclosure, in operation 1024, the EENT Priority checks whether the EVENT and EXT values are the same. In operation 1024, an internal event message 406 is generated and transmitted to step 2. If the result of the check 1025 is not the same, it is checked whether the look-up result of the Local OC table 511 is MS-W (1026). If it is correct, the internal event message 406 is generated (1015) and transmitted to step 2 of FIG. 11A. .

According to an embodiment of the present disclosure, in operation 1026, if the MS-W is not MS-W, the operation method of the global command request unit checks whether it is MS-P, if it is correct, internally generates an Operator Clear command (1029), and generates an internal event message 406. And transmits to step 2 of FIG. 11A. In step 1027, if not the MS-P, the Active Path SD Table 520 is looked up 1028. Then, the lookup result and the input internal event message 405 is selected to use the standby path (check whether it is local or remote) to generate the internal event messages 406 to 407 to transmit to step 2 of FIG.

11A to 11B are diagrams illustrating a method of operating a state transition controller of a packet protection switching device according to an embodiment.

The operation method of the state transition controller according to an embodiment receives internal event messages 406 through 407 from step 2 of FIG. 10, and stores them in a state transition queue 1110.

According to an exemplary embodiment of the present invention, after the state DB table 521 corresponding to the APC-ID of the internal event message output from step 1110 is looked up (1111), the upper field of the internal event message is GL ( Global Local) is checked (1112). If the result of the check 1112 is GL, the EVENT value is checked 1113, and whether the operator clear or the SFDc is checked (1114). If the result of the check (1114) is not Operator Clear or SFDc, the selected state is selected (1115) to check (1116) the current state information that is the result of the state DB table and check (1116). If the current state is PF: W: L, PF: DW: L, and not WTR of RFC7271, the lookup result of the Highest Persistent Local REQ Table (512) is converted to REQ / FP / DP, which is an APC frame field (1118). )do.

In operation 1116, the method of operating the state transition controller operates the WTR state machine when Condition-4, that is, the current state is PF: W: L, PF: DW: L, and WTR of the RFC7271. . In addition, according to an embodiment of the present invention, the method for operating the state transition controller updates 1117 the WTR Running Table 522 by the EVENT field of the internal event message or the combination of the AMR Table 517 and the Revertive Table 531. Subsequently, the operation method of the state transition controller according to an embodiment converts the lookup result of the Highest Persistent Local REQ Table 512 into REQ / FP / DP, which is an APC frame field (1118).

The operation method of the state transition controller according to an embodiment receives the converted information from step 1118, operates the Local Request State Machine (1119), and then updates (1133) the State DB Table. The operating method of the state transition controller according to an embodiment of the present disclosure checks current state information (1120) if the EVENT input from step 1114 is correct for Operator Clear or SFDc, and selects 1115 for local state machine if condition-1.

condition-1 means a condition other than condition-2 below.

According to an exemplary embodiment of the present invention, in operation 1120, condition-2, that is, the EVENT field value of the internal event message 406 is Operator Clear of FIG. 6 and the Current State is UA: LO: L, SA: F of the RFC7271 standard. : L, SA: MW: L, SA: MP: L, E :: L, WTR state or EVENT field value is SFDc and UA: P: L, UA: DP: L, PF: W: L, If the PF: DW: L state is selected, Complex Request State Machine is selected (1121).

In operation 1121, the method for operating the state transition controller determines whether the current state is a wait-to-restore (WTR) after step 1121, and if the current state is a wait-to-restore (WTR), the complex request state Machine 1126 can be operated. If the current state is not WTR (Wait-To-Restore), the AMR Table 517 is looked up (1123) and the result is converted into EVENT and EXT values (1124), and HPLR (Highest Persistent Local) of the internal event message 406 is displayed. Request) is converted into REQ / FP / DP, which is an APC frame field (1125). Thereafter, the operation method of the state transition controller according to an embodiment operates 1126 of the Complex Request State Machine. If it is not GL, it is checked from step 1112 (1127), otherwise it is discarded, and if it is correct, the Remote Request State Machine is selected (1128). After Checking Current State Information after Step 1128, if Condition-6, that is, if Current State is not WTR, convert the value of Highest Persistent Local Request (HPLR) of internal event message 407 to AQ frame field REQ / FP / DP. (1131).

According to an embodiment, the method of operating the state transition controller may operate the WTR state machine when Condition-5, that is, the current state is WTR after step 1128. Thereafter, after updating the WTR Running Table 522 (1130), the conversion of step 1131 is performed.

In operation 1131, the method of operating the state transition controller may operate 1132 of the Remote Request State Machine and update 1133 of the State DB Table 521. In addition, the operation method of the state transition controller according to an embodiment of the present invention checks whether a change in the DP (Data Path) occurs (1134), and if the change occurs, generates an internal event message 409 (1135), and step 3 of FIG. 13. Send to. In addition, the method for operating the state transition controller according to an embodiment generates an internal event message 408 and sends it to step 4 of FIG. 12A. If no change occurs in step 1134, only internal event message 408 is generated 1136 and sent to step 4 of FIG. 12A.

12A to 12C are diagrams illustrating an operation method of an APC message generator of a packet protection switching device according to an embodiment.

The method of operating the APC message generator according to an embodiment receives the internal event message 408 from step 4 of FIG. 11 and stores it in the TX APC Frame Queue 1210. If the frame cycle is valid after checking the valid frame cycle (1211) to receive the data output from the TX APC Frame Queue, go to step 1210 and if the frame cycle is not valid after waiting, receive the output data from the TX APC Frame Queue and generate the APC frame. Start 1212 and send to step 6 of FIG. 12C. At the same time, it is stored (1213) in the First Interval TX APC Queue. If the Frame cycle is valid after checking the Valid Frame cycle (1214) to receive data output from the First Interval TX APC Frame Queue, go to step 1213 and if the Frame cycle is not valid after waiting, receive the output data from the First Interval TX APC Frame Queue. First Interval APC frame generation service is started (1215) and sent to step 6 of FIG. 12C and stored 1216 in the Second Interval TX APC Queue.

The operation method of the APC message generating unit according to an embodiment checks the valid frame cycle (1217) to receive data output from the Second Interval TX APC Frame Queue, and if the frame cycle is valid, the process goes to step 1216 and waits. After that, if the frame cycle is not valid, it receives output data from Second Interval TX APC Frame Queue and starts the Second Interval APC frame generation service (1218) and sends it to Step 6 of FIG. 12C and corresponds to Periodic Job Memory of Step 5 of FIG. 12B. The APC-ID value is updated (1219). According to an embodiment of the present invention, the APC message generating unit operates in a valid frame cycle to receive a lookup data output from Periodic Job Memory (1217). If the frame cycle is valid, the procedure goes to step 1219. After looking up the Job Memory, the APC-ID information generation service is received (1221) and the Periodic APC frame generation service is started (1222). APC-ID information-related output data is also sent to step 6 of FIG. 12C, and the address 12 of the Periodic Job Memory is increased by 1223, and the check of step 1220 is repeated. From step 6 of FIG. 12C, the TX frame structure table 290 is looked up 1224, the APC frame is generated 1225 using the lookup result, and then the APC frame is transmitted 1226 through the data interface unit.

13 is a diagram illustrating a method of operating a Remote LoC and SetBS generator of a packet protection switching device according to an embodiment.

According to an exemplary embodiment of the present invention, the remote LoC and SetBS generators receive internal event messages 402 and 409 from step 3 of FIG. 11A and store them in a TX Frame Queue 1310. The operating method of the remote LoC and SetBS generating unit according to an embodiment may check the valid frame cycle to receive data output from the TX Frame Queue (1311) and then determine whether the frame cycle is valid. If valid, the operation method of the Remote LoC and SetBS generator according to an exemplary embodiment branches to step 1310. If the frame cycle is not valid, it receives output data from the TX Frame Queue and checks whether it is a SetBS generation command (GS field of internal event message 409) (1312). If the result of the check 1312 is set, if the SetBS generation command is correct, the target UNI Table 536 is looked up 1313 and it is checked 1314 whether one or more lookup result bitmaps of the Target UNI Table are set. If one or more bitmaps are not set as a result of the check 1314, discard them. If the one or more bitmaps are set, the TX frame structure table, the aggregation table 537, and the L2 DA table 535 are looked up.

According to an embodiment of the present invention, a method of operating a remote LoC and a SetBS generator includes starting a SetBS generation service using the result of operation 1315 (1316), transmitting a SetBS frame through a data interface unit (1317), and serving a target UNI bit. Clears 1318 and branches to step 1314.

According to an operation of the remote LoC and SetBS generating unit according to an embodiment, according to the result of check (1312), it is checked whether the R-LoC / CLoC frame is valid by checking whether it is an internal event message 402 or not if it is a SetBS generating command (1319). If it is not valid, discard the process. If the result of check 1319 is valid, the TX Frame Structure Table 290 and the Remote L2 DA Table 532 are looked up 1320. According to an embodiment of the present invention, a method of operating a remote LoC and SetBS generating unit starts 1322 a remote LoC / CLoC generation service using a result of step 1320, transmits a Remote LoC / CLoC frame through a data interface unit 1322, and ends. do.

After all, according to the present invention, when a failure occurs in the packet transmission network, it is possible to increase the number of protection switching connections managed in connection with the packet transmission path and to perform protection switching for a fast and stable packet transmission path. In addition, according to the present invention, by processing the packet transmission path protection switching on a hardware basis, it is possible to quickly process the path protection switching for the transmission path change in the packet processor, thereby reducing the loss of transmitted packets.

Method according to an embodiment of the present invention can be implemented in the form of program instructions that can be executed by various computer means may be recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

Claims (20)

A data interface unit for receiving a frame;
Determine an output path based on the type of the received frame,
Determine whether the received frame is a working path or protection path operated by a local line card, and if the received frame is the working path or protection path, converts the received frame into an internal event message. and,
Determine whether it is generated in a path that is currently transmitting or receiving traffic in the working path or the protection path, and determining whether to transmit the converted internal event message according to a determination result,
A processor configured to determine a highest priority request from the transmitted internal event message and an operator command transmitted from a host processor, and to generate an internal event message in consideration of the determined highest priority request; And
A generator configured to generate at least one of a frame based on a protection switching protocol and a frame for changing a packet transmission path from the generated internal event message
Including,
And the data interface unit transmits the generated frame to each packet processor in a line card. delete The method of claim 1,
The processing unit,
The priority request is determined by comparing priorities with previously stored persistent requests in consideration of an operator command received from the host processor of the line card, and the determined highest priority request is determined. Packet protection switching device to generate an internal event message in consideration of the request). delete delete The method of claim 1,
The data interface unit receives at least one of an APC frame, a Loss of Continuity (LoC) / Clear Loss of Continuity (LoC) frame, and a Remote LoC / CLoC frame from a packet processor,
The processing unit,
A parsing unit extracting a field of the received frame to check a type of the received frame and to determine an output path based on the type of the identified frame;
When the received frame is a Loss of Continuity (LoC) / Clear Loss of Continuity (CLoC) frame, a frame received from the parser is received and the received frame is operated by an APC process operated on a local line card. A LOC detector that determines whether the path is a working path or a protection path, and converts the received frame into an internal event message when the working path or protection path is operated on a local line card;
HO (HOLD-OFF) for determining whether the generated internal event message is transmitted or not according to a determination result, whether it is generated in a path that is currently transmitting or receiving traffic in the working path or the protection path. A decision unit; And
A local command request unit which determines a highest priority request from the transmitted internal event message and an operator command transmitted from a host processor, and generates an internal event message in consideration of the determined highest priority request.
Packet protection switching device comprising a. delete delete delete delete delete delete The method of claim 1,
The generation unit,
A global command request unit that determines a global top priority request in response to the internal event message, and outputs at least one of an internal event message that is a global local command and an internal event message that is a global remote command based on the determination;
A state transition control unit which receives the output internal event message and performs state transition in consideration of an operator command; And
APC message generation unit for looking up the TX frame table based on the state transition internal event message, and requesting the data interface to encode the APC frame according to the lookup result and send it to the packet processor of the corresponding line card.
Packet protection switching device comprising a. The method of claim 13,
Remote LoC and SetBS Generator
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The remote LoC and SetBS generation unit,
Refers to a lookup result, generates a remote LoC / CLoC frame based on the referenced lookup result, and protects the packet requesting the data interface to send the generated remote LoC / CLoC frame to another line card of the same local packet delivery system. Switching device. delete Receiving, at the data interface unit, a frame from a packet processor of the line card;
In the processing unit, the output path is determined based on the type of the received frame,
Determine whether the received frame is a working path or protection path operated by a local line card, and if the received frame is the working path or protection path, converts the received frame into an internal event message. and,
Determine whether it is generated in a path that is currently transmitting or receiving traffic in the working path or the protection path, and determining whether to transmit the converted internal event message according to a determination result,
Determining a highest priority request from the transmitted internal event message and an operator command transmitted from a host processor, and generating an internal event message in consideration of the determined highest priority request;
Generating at least one of a frame based on a protection switching protocol and a frame for changing a packet transmission path from the generated internal event message; And
Sending, at the data interface unit, the generated frame to each packet processor in a line card
Packet protection switching method comprising a. The method of claim 16,
Receiving an operator command from a host processor of the line card in a control interface unit
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Generating the internal event message,
Determining a highest priority request by comparing a priority with previously stored persistent requests in consideration of the received operator command; And
Generating an internal event message in consideration of the determined highest priority request
Packet protection switching method comprising a. The method of claim 17,
Generating at least one of a frame based on the protection switching protocol and a frame for changing a packet transmission path,
Determining a global top priority request in response to the internal event message;
Outputting at least one of an internal event message, which is a global local command, and an internal event message, which is a global remote command, based on the determination;
Receiving the output internal event message and performing a state transition in consideration of an operator command;
Looking up a TX frame structure table based on the state transitioned internal event message; And
Requesting the data interface to encode and send an APC frame to the packet processor of the corresponding line card according to the lookup result;
Packet protection switching method comprising a. The method of claim 18,
Referring to the lookup result and generating a remote LoC / CLoC frame based on the referenced lookup result; And
Requesting the data interface to transmit the generated remote LoC / CLoC frame to another line card of the same local packet delivery system
Packet protection switching method further comprising. The method of claim 18,
Analyzing the state transition internal event message and generating a SetBS frame with reference to a lookup result; And
Requesting the data interface to send the generated SetBS frame to each packet processor in a single line card or multiple line cards
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The packet processor that receives the SetBS frame performs the transfer path protection switching.

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