KR101892272B1 - Apparatus and method of failure classification based on bidirectional forwarding detection protocol - Google Patents

Abstract

The present invention relates to a technical idea of detecting a cause of a defect when a defect is detected through a bidirectional forwarding detection (BFD) protocol. The defect classification apparatus according to an embodiment sets a survival confirmation bit in a BFD protocol control packet A determination unit for determining whether a timeout occurs by counting a predetermined time after transmitting the BFD protocol control packet, and a determination unit for determining whether a defect occurs in a link with a neighboring system, And a defect cause classifying unit for classifying whether the defect is generated in the system.

Description

[0001] APPARATUS AND METHOD OF FAILURE CLASSIFICATION BASED ON BIDIRECTIONAL FORWARDING DETECTION PROTOCOL [0002]

The present invention relates to a defect classification apparatus and method based on Bidirectional Forwarding Detection (BFD) protocol, and more particularly, to a technical idea for detecting a cause of a defect when a defect is detected through the BFD protocol.

When delivering services, Internet service providers must ensure network survivability so that they can reliably handle large-scale network infrastructures and explosive traffic requests. That is, even if a fault occurs in a large-scale network infrastructure, it should be detected and quickly restored to enable continuous service. Various researches have been carried out for this purpose. Typically, there is a BFD protocol for detecting a defect using a bidirectional transmission path between forwarding planes of two adjacent systems.

The BFD protocol is a protocol that is used to detect errors in bi-directional paths between two transmission engines, and the detection is rapid in certain circumstances as the Data Link hardware begins to operate. The BFD protocol can detect communication errors in the data plane next hop. The protocols supporting the BFD protocol include Open Shortest Path First (OSPF), Intermediate System Intermediate System (IS-IS), Enhanced Interior Gateway Routing Protocol (EIGRP), and Border Gateway Protocol (BGP).

Although the BFD protocol can detect a defect, there is a problem that it can not be determined whether the defect is caused by a link defect or a service function defect. When a fault occurs, it must be known to recover the fault.

Korean Patent No. 10-1281250 Korean Patent No. 10-0887290

An object of the present invention is to grasp the cause of a defect when a defect is detected through the BFD protocol.

The present invention also aims at ensuring the survivability of a network by stably processing a large-scale network infrastructure and a sudden traffic request.

A defect classification apparatus according to an exemplary embodiment of the present invention includes a packet transmitter for setting a survival confirmation bit in a bidirectional forwarding detection (BFD) protocol control packet and counting a predetermined time after transmitting the bidirectional forwarding detection (BFD) And a defect classifying unit for classifying whether a defect occurs in a link with the adjacent system or a defect occurring in the adjacent system in consideration of the determined timeout.

A method of classifying a defect according to an exemplary embodiment of the present invention includes the steps of setting and transmitting a survival confirmation bit in a bidirectional forwarding detection (BFD) protocol control packet in a packet transmission unit, and transmitting a bidirectional forwarding detection (BFD) A step of counting a predetermined period of time to determine whether or not a timeout occurs, and a step of classifying whether a defect occurs in a link with the adjacent system or a defect occurring in the adjacent system, in consideration of the determined timeout .

According to the present invention, it is possible to classify defects, defects of link defects and service functions through the BFD protocol.

In addition, there is an effect of ensuring the survivability of the network by stably handling a large-scale network infrastructure and a rapidly increasing traffic demand.

1 is a view for explaining a defect sorting apparatus according to an embodiment.
2 is a diagram for explaining a bidirectional forwarding detection (BFD) protocol control packet.
3 is a view for explaining transmission of a survival confirmation message through a BFD protocol control packet.
4 is a view for explaining a defect classification method according to an embodiment.

It is to be understood that the specific structural or functional descriptions of embodiments of the present invention disclosed herein are only for the purpose of illustrating embodiments of the inventive concept, But may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Embodiments in accordance with the concepts of the present invention are capable of various modifications and may take various forms, so that the embodiments are illustrated in the drawings and described in detail herein. However, it is not intended to limit the embodiments according to the concepts of the present invention to the specific disclosure forms, but includes changes, equivalents, or alternatives falling within the spirit and scope of the present invention.

The terms first, second, or the like may be used to describe various elements, but the elements should not be limited by the terms. The terms may be named for the purpose of distinguishing one element from another, for example without departing from the scope of the right according to the concept of the present invention, the first element being referred to as the second element, Similarly, the second component may also be referred to as the first component.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Expressions that describe the relationship between components, for example, "between" and "immediately" or "directly adjacent to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises ", or" having ", and the like, are used to specify one or more of the features, numbers, steps, operations, elements, But do not preclude the presence or addition of steps, operations, elements, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning of the context in the relevant art and, unless explicitly defined herein, are to be interpreted as ideal or overly formal Do not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, the scope of the patent application is not limited or limited by these embodiments. Like reference symbols in the drawings denote like elements.

1 is a view for explaining a defect classifying apparatus 100 according to an embodiment.

The defect classification apparatus 100 according to an embodiment can classify a defect detection and a defect of a link defect and a service function through the BFD protocol. In addition, it can ensure the survivability of the network by reliably handling large-scale network infrastructures and explosive traffic requests.

For this purpose, the defect classification apparatus 100 may include a packet transfer unit 110, a determination unit 120, and a defect cause classification unit 130.

First, the packet transmitter 110 according to an embodiment may set a survival confirmation bit in a bidirectional forwarding detection (BFD) protocol control packet and transmit it to an adjacent system.

At this time, the survival confirmation bit is a bit that does not exist in a general BFD (bidirectional forwarding detection) protocol control packet and can be interpreted as a bit added by the packet transmission unit 110. To this end, the packet transmitter 110 may reduce a specific field in a field of an existing BFD protocol control packet and newly add a bit for confirmation of survival.

For example, the packet transmission unit 110 may allocate 1 bit as a bit for confirming the existence. Specifically, the packet transmission unit 110 may indicate whether to confirm the survival through the allocated 1 bit. The BFD protocol control packet to which the survival confirmation bit is added will be described in detail later with reference to FIG.

Referring again to FIG. 1, the determination unit 120 may determine whether a timeout occurs by counting a predetermined time after transmitting a BFD protocol control packet.

For example, the BFD protocol control packet may be transmitted to the adjacent system through the packet transfer unit 110, and the BFD protocol control packet to be transmitted may be received from a service function (or a node providing a service function) . The timeout value can be set by the system administrator or at the time of mass production, and can be set considering system performance or service performance. As another example, the timeout value may be determined by negotiation between the two systems in the session.

The defect cause classifying unit 130 according to an embodiment can classify a defect occurring in a link with a neighboring system or a defect occurring in an adjacent system in consideration of a determined timeout.

That is, if the response to the existence confirmation message does not come until the timeout occurs, the defect cause classifying unit 130 can determine that there is a link defect with the adjacent system. In addition, the failure cause classifying unit 130 may determine that a failure of the service function occurs when a response is generated from a switch connected to the failure function classifier 130, not from a service function for which a session is established until a timeout occurs.

That is, if a response to the BFD protocol control packet is not received within the predetermined time as a result of the counting, the defect cause classifying unit 130 classifies the defect as a defect occurring in the link with the adjacent system. In addition, if a reply to the BFD protocol control packet arrives within a predetermined time after the counting result, the defect cause classifying unit 130 classifies the defect as a defect occurring in the service function of the adjacent system. At this time, the defect classifier 130 may receive a reply to the BFD protocol control packet from the switch connected to the service function of the adjacent system.

2 is a diagram illustrating a BFD protocol control packet.

Reference numeral 210 in FIG. 2 denotes an existing BFD protocol control packet.

Among the fields of the BFD protocol control packet, the diagnostic field 211 (Diag field) is currently allocated with 5 bits ranging from 0 to 31. The Diag field 211 indicates the most recent state of the session. Currently, only 0 to 8 are defined, and 9 to 31 are empty for future use purposes.

Therefore, in the present invention, among the fields of the BFD protocol control packet, a survival confirmation message can be controlled using a diagnosis field 211 (Diag field).

Specifically, reference numeral 220 denotes a BFD protocol control packet, in which the diagnosis field 221 (Diag field 221) can use only 4 bits instead of 5 bits. Also, a survival confirmation bit 222 (N bit) may be added utilizing some bits of the Diag field 211.

That is, the existing Diag portion can be reduced to 4 bits and 1 bit can be assigned to 'N' for the survival confirmation message control. Currently, the BFD protocol survival confirmation method sends a survival confirmation message and continuously sends a survival confirmation message until a predetermined timeout. Therefore, in the case of the first survival confirmation message, the 'N' part may be set to '0', and in the case of the survival confirmation message repeatedly transmitted before the timeout, 'N' may be transmitted as '1'.

In this case, the switch to which the service function is connected transmits '0' to the service function (or the node that provides the service function), but if it is '1', it sends a survival confirmation response .

As a result, the defect classification apparatus of the present invention counts a predetermined time after transmitting the BFD protocol control packet, and can determine whether a response to the survival confirmation message comes before the counting result timeout. As a result of the determination, if it is not possible to return a response to the survival confirmation message within a predetermined time, it can be determined that a defect has occurred in the link with the adjacent system, not the defect in the adjacent system.

In addition, although the defect classification apparatus of the present invention returns a response to the survival confirmation message until timeout, in particular, when a response from a switch connected thereto is returned not from a service function in which a session is established, It can be judged that it has occurred.

FIG. 3 is a view illustrating transmission of a survival confirmation message through a BFD protocol control packet.

In the present invention, the Diag part of the existing BFD protocol control packet can be reduced to 4 bits and 1 bit can be assigned to 'N' for the survival confirmation message control.

In addition, a BFD session can be established between the first service function (SF1, or the node providing the first service function) and the third service function (SF3, or the node providing the third service function).

According to the set BFD session, the system can transmit the BFD protocol control packet from the first service function SF1 to the third service function SF3. In addition, a survival confirmation message can be sent to the third service function (SF3) through the first service function (SF1), and the survival confirmation message can be continuously transmitted until a predetermined timeout. In this case, the 'N' part of the first survival confirmation message is set to '0', and is set to '1' in the case of the survival confirmation message repeatedly transmitted before the timeout. In this case, the switch to which the service function is connected transmits '0' when the 'N' part is 0, to the service function, but when it is 1, it can return a response from SW3 to the transmitted part.

4 is a view for explaining a defect classification method according to an embodiment.

A defect classification method according to an embodiment may establish a BFD session.

The BFD protocol is a protocol for detecting a defect using a bi-directional transmission path between the forwarding planes of two adjacent systems. To do this, two adjacent systems establish a session using BFD protocol control packets to detect failures. A session may form a session through a three-way handshake scheme such as TCP. Once a session is established, it is possible to negotiate the period of the survival confirmation message and the timeout value for the survival confirmation message response. Based on the negotiated value, the two forwarding engines can send a survival confirmation message and send and receive responses. At this time, the survival confirmation message is continuously transmitted until the response to the BFD survival confirmation message becomes timeout, and when the timeout occurs, it is determined that a defect occurs in the adjacent system and the session is down.

This allows us to continuously check the survivability between two adjacent systems.

According to the present invention, if a response to the survival confirmation message does not arrive before the timeout, it is determined that the link is defective and the response from the switch connected to the service function It can be judged that a defect has occurred.

Specifically, the defect classification method according to an exemplary embodiment may control to transmit a survival confirmation message from the current system to the neighbor system as the BFD session is established (step 401). Next, the defect classification method according to one embodiment may determine whether or not a response to the confirmation of survival is returned through step 402. If it is determined in step 402 that the response to the existence confirmation is returned, the defect classification method may further determine whether the response is from the switch (step 403). If it is determined in step 403 that the response from the switch is returned, the defect classification method can confirm the survival of the adjacent system (step 404).

Meanwhile, if there is no response to the existence confirmation as a result of the determination in step 402, the defect classification method according to an exemplary embodiment may determine whether the timeout has been exceeded through step 406 (step 406). If it is determined in step 406 that the timeout has been exceeded, the survival confirmation message may be transmitted to the neighboring system again (step 405). At this time, the defect classification method can transmit by setting N bits of the survival confirmation message to 1.

If it is determined in step 406 that the timeout has been exceeded, the defect classification method can be determined to be a link defect with the adjacent system.

If it is determined in step 403 that the response is a response from the switch, the defect classification method may further determine in step 407 whether the response is within a timeout.

As a result of the determination in step 407, if the response is within the timeout, the defect classification method may generate a survival confirmation message as in step 405 and transmit it to the adjacent system.

As a result of the determination in step 407, if the response is within the timeout, the defect classification method can be determined to be a defect in the service function in step 408 instead of a defect occurring in the link with the adjacent system.

As a result, when using the present invention, it is possible to classify the defect detection and link defect and the defective service function through the BFD protocol. In addition, large-scale network infrastructure and surging traffic requests can be reliably handled to ensure network survivability.

The apparatus described above may be implemented as a hardware component, a software component, and / or a combination of hardware components and software components. For example, the apparatus and components described in the embodiments may be implemented within a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), a PLU a programmable logic unit, a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing unit may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device , Or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media 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 machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

100: Defect classification device
110: Packet transmission unit
120:
130: Defect Cause Classification

Claims (10)

A packet transfer unit for setting a survival confirmation bit in a bidirectional forwarding detection (BFD) protocol control packet and transmitting the same a plurality of times;
A determination unit for determining whether a timeout occurs by counting a predetermined time after transmitting the first BFD protocol control packet among BFD protocol control packets transmitted a plurality of times; And
And a defect cause classifying unit for classifying a defect occurring in a link with the adjacent system or a defect occurring in the adjacent system in consideration of the determined timeout,
The defect-
If a response to the BFD protocol control packet does not arrive for the predetermined time as a result of the counting, it is classified as a defect occurring in a link with the adjacent system,
If the reply to the BFD protocol control packet arrives from the switch connected to the service function of the adjacent system within the predetermined time as a result of the counting,
The survival confirmation bits of the first BFD protocol control packet and the survival confirmation bits of the remaining BFD protocol control packets other than the first BFD protocol control packet are set to be different from each other,
Defect classification device.
The method according to claim 1,
Wherein the packet transfer unit comprises:
Setting one bit of the 5-bit Diag field to the survival confirmation bit among the fields of the BFD protocol control packet,
Defect classification device.
delete delete delete Transmitting a plurality of times by setting a survival confirmation bit in a BFD protocol control packet included in a defect classification apparatus;
Counting a predetermined time after transmitting the first BFD protocol control packet among the BFD protocol control packets transmitted by the determination unit included in the defect classification apparatus a plurality of times to determine whether a timeout occurs; And
Classifying the defect classifying unit included in the defect classifying apparatus as a defect occurring in a link with the adjacent system or a defect occurring in the adjacent system in consideration of the determined timeout,
The method of claim 1,
If a response to the BFD protocol control packet does not arrive for the predetermined time as a result of the counting, it is classified as a defect occurring in a link with the adjacent system,
If the reply to the BFD protocol control packet arrives from the switch connected to the service function of the adjacent system within the predetermined time as a result of the counting,
The survival confirmation bits of the first BFD protocol control packet and the survival confirmation bits of the remaining BFD protocol control packets other than the first BFD protocol control packet are set to be different from each other,
Defect classification method.
The method according to claim 6,
Wherein the transmitting comprises:
Setting one bit of the 5-bit Diag field to the survival confirmation bit among the fields of the BFD protocol control packet.
Defect classification method.
delete delete delete

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