KR20210075501A - Network management apparatus and control method thereof - Google Patents

Abstract

The present invention relates to a network management device and a control method thereof. According to the present invention, the control method for the network management device includes the following steps of: requesting a software defined network (SDN) controller communicating with at least one SDN packet processor for the collection of state information of each SDN packet processor and receiving the information; comparing the state information of each SDN packet processor received from the SDN controller at the previous step, with pre-stored state information; and sorting out a case in which the information is not matched as a result of the comparison, and then, requesting the SDN controller for switchover or recovery control for a corresponding SDN packet processor. Therefore, the present invention is capable of quickly handling a failure by automatically determining the failure.

Description

NETWORK MANAGEMENT APPARATUS AND CONTROL METHOD THEREOF

The present invention relates to a network management apparatus and a control method thereof, and more particularly, to a network management apparatus communicating with at least one SDN (Software Defined Network) controller to transmit/receive request and control messages, and to a control method thereof.

For communication, various network devices must be configured, for example, a switch, a router, etc. are representative examples.

However, these network devices may fail due to their own problems or excessive traffic received from the outside. In the past, when a failure of these network devices occurred, the network operator manually performed switching, recovery, packet bypass, etc. .

1 shows a conventional processing process when a network failure occurs.

Referring to FIG. 1 , in a situation in which a security policy for allowing user traffic through the first switch 11 to pass through the firewall of the second switch 12 is applied and processed, measures are taken when a failure of the first switch 11 occurs. To this end, the network operator transfers the first switch 11 and manually allocates the resources of the second switch 12 so that the user's service can be continued.

Thereafter, the operator must manually recover the resources previously allocated to the second switch 12 in order to utilize the first switch 11 again when the failure of the first switch 11 is resolved after the failure of the first switch 11 is resolved. 11), user traffic can be processed.

However, since such a conventional method is always performed according to the manual operation of a network operator, rapid processing cannot be performed, which is a factor causing a lot of time and cost.

This is the same problem that occurs in SDN (Software Defined Network) divided into SDN controller and SDN packet processing device.

SDN refers to a network system configured by separating the network equipment that previously performed both control control and packet processing from the control control module and packet processing module. In this case, in particular, the introduction of a consistent control method for the control control modules of various vendors. This is an urgent situation.

Patent Publication No. 10-2016-0011089

The present invention has been devised in order to meet the above problems and requests in the prior art, and its object is to enable rapid processing when a failure occurs in a network device, and to achieve consistent control of SDN systems of different vendors in particular. To provide an apparatus and a method for controlling the same.

In order to achieve the above object, a network management apparatus according to the present invention collects information that requests and receives at least one SDN (Software Defined Network) packet processing apparatus and an SDN controller to collect status information of each SDN packet processing apparatus. wealth; a state information comparison unit for comparing the state information of each SDN packet processing device received from the SDN controller by the request collection unit with previously stored state information; and a control requesting unit requesting the SDN controller to switch over or restore control to the corresponding SDN packet processing apparatus after selecting a case where the comparison result of the state information comparison unit does not match.

In addition, in order to achieve the above object, the method for controlling a network management apparatus according to the present invention requests an SDN controller that communicates with at least one SDN (Software Defined Network) packet processing apparatus to collect status information of each SDN packet processing apparatus. to receive; comparing the state information of each SDN packet processing device received from the SDN controller with pre-stored state information; and requesting the SDN controller to switch over or restore control to the corresponding SDN packet processing device after selecting a case that does not match the result of the comparison in the above step.

As described above, according to the present invention, when a failure of an SDN packet processing device such as a switch occurs, it is possible to automatically determine a failure and perform measures and recovery, thereby enabling rapid failure handling.

In particular, since the network management device communicates with the SDN controller using a standardized protocol called HTTP, it is possible to control each SDN controller configured by different vendors in the same and consistent manner.

Furthermore, it is possible to minimize the possibility of message loss according to HTTP communication through a method of transmitting repeated messages.

1 is a diagram showing a process manually operated by a network operator when a conventional switch failure occurs;
2 is a schematic configuration diagram of an entire system including a network management apparatus according to an embodiment of the present invention;
3 is a functional block diagram of the network management apparatus of FIG. 2;
Figure 4 is a control flow diagram of the network management device of Figure 2,
5 and 6 are examples of codes of program modules of the network management apparatus of FIG. 2 .

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

Hereinafter, each embodiment according to the present invention is merely an example for helping understanding of the present invention, and the present invention is not limited to these embodiments. In particular, the present invention may be composed of a combination of at least any one of individual components, individual functions, or individual steps included in each embodiment.

In particular, for convenience, some of the claims include an alphabet such as '(a)', but the alphabet does not define the order of each step.

A schematic configuration of the entire system including the network management apparatus 100 according to an embodiment of the present invention is shown in FIG. 2 .

In FIG. 2 , the SDN controller 200 and the SDN packet processing device 300 are components constituting a Software Defined Network (SDN), and control functions and packet processing functions among the functions of network equipment such as conventional switch equipment. As a separate form, such a soft definition network itself corresponds to a known technology, so a more detailed description will be omitted.

The SDN packet processing device 300 performs a function of processing an actual communication packet (ie, passing, dropping, forwarding, etc.), and the SDN controller 200 is connected to at least one SDN packet processing device 300 and , a function of collecting status information (for example, whether it is operating, whether a failure has occurred, etc.) of each SDN packet processing device 300, as well as various control signals to each SDN packet processing device 300 It performs the function of sending.

For example, the SDN packet processing apparatus 300 may perform individual processing of a packet having a specific address as a source under the control of the SDN controller 200 .

Meanwhile, the network management device 100 communicates with at least one SDN controller 200 to transmit various request signals or request messages, and in particular, transmits state information of each SDN packet processing device 300 to the SDN controller 200 . Alternatively, control of each SDN packet processing device 300 may be requested from the SDN controller 200 .

An example of a specific functional block of the network management apparatus 100 is shown in FIG. 3 .

As shown in the figure, the network management apparatus 100 may include an information collection unit 110 , a state information comparison unit 120 , a control request unit 130 , and a storage unit 140 .

The storage unit 140 not only stores various types of information, data, or applications necessary for the operation of the network management apparatus 100 , but also functions to store information generated during the operation of the network management apparatus 100 or received from the outside. carry out

In particular, the storage unit 140 may store the state information of each SDN packet processing device 300 received from each SDN controller 200, wherein the status information of each SDN packet processing device 300 operates normally and It may be either an 'operational state' indicating that there is or a 'failure state' indicating that a predetermined failure has occurred.

The information collection unit 110 requests and receives the state information of each SDN packet processing device 300 from the SDN controller 200 .

That is, as described above, the SDN controller 200 can check the state of each SDN packet processing device 300 managed by it using port scanning or an Internet Control Message Protocol (ICMP) signal. ) may request and receive the operation state of each SDN packet processing device 300 from the SDN controller 200 as described above.

Communication between the information collection unit 110 and the SDN controller 200 may be accomplished by sending and receiving a message according to HTTP (HyperText Transfer Protocol).

In particular, the information collection unit 110 assigns a serial number to each request message during communication with the SDN controller 200 , and when receiving a serial number missing message from the SDN controller 200 , the information collection unit 110 corresponds to the missing serial number. Transmit messages can be retransmitted.

As another example, the information collection unit 110 may transmit the same message a preset number of times at a preset time interval during communication with the SDN controller 200 .

Both using the serial number and transmitting the same message a preset number of times are to prevent message omission due to HTTP communication in advance.

The state information comparison unit 120 compares the state information of each SDN packet processing device 300 received from the SDN controller 200 by the request collection unit with pre-stored state information and performs a function of updating it. .

The control requesting unit 130 performs a function of transmitting a predetermined request message or a request signal to the SDN controller 200 with reference to the comparison result of the state information comparison unit 120 .

Specifically, the control request unit 130 compares the result of the state information comparison unit 120 , that is, the state information of each SDN packet processing unit 300 newly received from the SDN controller 200 and each SDN packet processing unit 300 . As a result of comparing state information that is matched to and registered in advance, a case is selected that does not match, and a request signal or message for switching or restoration control for the SDN packet processing device 300 that does not match the state information is sent to the SDN controller. can be sent to (200).

The communication between the control requesting unit 130 and the SDN controller 200 may be performed by message transmission/reception according to the HTTP (HyperText Transfer Protocol), similarly to the communication between the information collection unit 110 and the SDN controller 200 above.

In addition, as mentioned in the information collection unit 110 above, the control request unit 130 assigns a serial number to a control message during communication with the SDN controller 200 , and receives a serial number missing message from the SDN controller 200 . In one case, the control message corresponding to the missing serial number may be retransmitted.

As another example, the control request unit 130 may transmit the same message a preset number of times at a preset time interval during communication with the SDN controller 200, and transmits the same message as using this serial number a preset number of times. All of these are to prevent message omission according to HTTP communication in advance, as described above.

When the function of the control request unit 130 is described in detail, as a result of the comparison of the state information comparison unit 120, when the state information for the specific SDN packet processing device 300 is changed from the 'operational state' to the 'failure state', A request message for making a packet path detour to another SDN packet processing device 300 maintained in an 'operational state' along with switching to the specific SDN packet processing device 300 may be transmitted to the SDN controller 200 .

Here, 'switching' means preventing a specific SDN packet processing device 300 from being used, and 'bypassing' means redirecting a packet destined for the switched specific SDN packet processing device 300 to another SDN packet processing device 300. It means to convert to

That is, since the communication failure cannot be resolved only by switching the specific SDN packet processing device 300 in which the failure has occurred so that packets are no longer transmitted to the specific SDN packet processing device 300, the control request unit 130 is This is to transmit a message setting the other SDN packet processing device 300 to process the packet processed by the specific SDN packet processing device 300 .

Such packet detour processing includes a process of changing/updating a routing table, etc., which corresponds to a known technique, and thus a more detailed description thereof will be omitted.

In addition, the control request unit 130, when the state information about the specific SDN packet processing apparatus 300 is changed from the 'failure state' to the 'operation state' as a result of the comparison of the state information comparison unit 120, the control request unit 130 processes the specific SDN packet Along with the recovery of the device 300 , it also performs a function of restoring the other SDN packet processing device 300 that has performed detour processing on the packet to the specific SDN packet processing device 300 .

Here, 'restore' means to allow the SDN packet processing device 300 whose failure state is resolved to perform the packet processing function again, and 'restore' means to process packet detours for other SDN packet processing devices 300 . It means to stop the operation and return to the original state.

That is, normal communication is not performed only by restoring the SDN packet processing device 300 in which the failure state is resolved, and the SDN packet processing device 300 that has previously been in charge of the bypass processing is no longer in charge of the bypass processing. Therefore, the control request unit 130 processes both 'restore' and 'restore'.

Hereinafter, an overall control process of the network management apparatus 100 according to an embodiment of the present invention will be described with reference to FIG. 4 .

Assuming that a plurality of SDN controllers 200 exist, the network management apparatus 100 checks connectivity of each of the plurality of SDN controllers 200 (step S1).

In general, in the configuration of the SDN controller 200, the multiplexed SDN controllers 200 logically operate as one, but may be physically configured in different locations, and the network management device 100 is configured in such different locations. It is to continuously check the connectivity of each of the SDN controllers 200 . The connectivity check for each of the SDN controllers 200 located in different regions may be performed in a manner that attempts as many as the number of the SDN controllers 200 using ICMP (Internet Control Message Protocol).

In this case, when the connectivity check of all SDN controllers 200 fails, the network management device 100 may transmit a notification message for checking the physical connection state of the SDN controllers 200 to the manager (or operator).

When the connectivity check with the specific SDN controller 200 is normally performed, the network management device 100 can check whether communication is possible with the corresponding SDN controller 200 (step S3), for example, each SDN controller 200 . You can check it using the REST API, which is an HTTP-based Northbound interface provided by .

Checking whether communication is possible can be confirmed through the HTTP response code that the SDN controller 200 responds to when delivering a message through the REST API.

When all status checks with the SDN controller 200 are finished, the network management device 100 collects the current network resource usage status and checks the status of each SDN packet processing device 300 (eg, a switch) through the SDN controller 200 . An operation for transmitting a confirmation command is performed (step S5).

A command transmission operation for collecting the network resource usage status and checking the status of the SDN packet processing apparatuses 300 may also be performed by the REST API.

The network management device 100, which has received the state of each SDN packet processing device 300 from the SDN controller 200, transmits the received status information and pre-stored status information of the corresponding SDN packet processing device 300 (that is, the previous state information) to determine whether the state of the SDN packet processing apparatus 300 is in a failure state or is restored from a failure state (step S7).

As a result of the determination, when the state of the SDN packet processing apparatus 300 is switched from the operation state to the failure state (step S7), the network management apparatus 100 switches to the SDN packet processing apparatus 300 switched to the corresponding failure state and A control message for processing the packet detour to another location is transmitted to the SDN controller 200 (step S9).

In addition, when the state of the SDN packet processing apparatus 300 is changed from the faulty state to the operational state as a result of the determination (step S11), the network management apparatus 100 restores the SDN packet processing apparatus 300 switched to the operational state. In addition to performing the recovery process, the SDN packet processing apparatus 300, which was previously in charge of packet detour, is restored (step S13).

The network management apparatus 100 may be operated by a kind of SDN application program, and the processing process thereof is shown in FIGS. 5 to 6 .

FIG. 5(a) is an example (pseudo code) of a first program module in which the SDN application program checks the connectivity of the SDN controllers 200 .

The first program module receives the IP address array (SDNC IP LIST) of the SDN controllers 200 to be checked for connectivity as an input factor, and sends an ICMP message to the IP of one SDN controller 200 in the array received as an input factor and then sends a response. Receive and check connectivity.

If the response to the ICMP message is normally received, the first program module returns the IP address of the corresponding SDN controller 200, and if the message response fails, the connection is checked again with the IP address of another SDN controller 200 in the IP address array. Repeat the process.

If the connectivity check of all the SDN controllers 200 fails, the entire program may be terminated to check the physical connection state of the SDN controllers 200 .

5( b ) is an example of a second program module for checking REST API communication whether the SDN application program can transmit a setting command to the SDN controller 200 .

The second program module transmits the REST API message to the IP address returned by the SDN controller 200 connectivity check module, receives a response, and checks whether communication with the SDN controller 200 is established.

The response message informs the result of the REST API processing of the SDN controller 200 as a response code, and when the response code is the integer '200', the second program module may determine the communication state as normal.

If the response code is an integer other than '200', the second program module determines that there is an error in the setting contents (REQUEST BODY) transmitted to the REST API, automatically terminates the program, and can notify the administrator.

In particular, as described above, a 3-Duplicate Acknowledge technique may be applied to improve the reliability of the REST API. The operation method is as follows.

If a response is not received for a certain period of time after delivery of the REST API for communication confirmation, the response code is judged as 'NULL' (no response), and if a message with a response code of 'NULL' is received three times, the SDN controller ( 200) is called to check the connectivity of the other SDN controller 200 and whether communication is possible.

The reason why the three-time duplicate response technique is applied to the REST API is to improve reliability by preventing messages from being dropped due to the temporary disconnection of the communication state between the SDN application program and the SDN controller 200 in advance.

6( a ) shows an example of a third program module for checking the status of switches managed by the SDN application program by collecting the current network resource usage status through the SDN controller 200 .

The third program module receives the ID array (SWITCH ID LIST) of the switches (that is, the SDN packet processing devices 300) for which the usage status collection and status are to be checked as an input factor, and the resource usage status collection and status for each switch The REST API for confirmation is transmitted to the SDN controller 200, and when a normal response is received, the current resource usage status and status information of the switch are received through a response message (RESPONSE BODY).

The received current resource usage status and status information is stored in an array (STATUS LIST). At this time, the third program module repeats until all switches managed are checked, and the array in which the current resource usage status and status information of all switches is stored. return

The returned array can be stored in a database for comparison with the previous state of the switch or to calculate a detour path in case of a switch failure.

In addition, it goes without saying that the third program module can also apply the three-time duplicate response technique in case the REST API fails.

6(b) is an example of a fourth program module that requests a command so that the SDN controller 200 performs an action or recovery operation when the state of the managed switch is changed.

The fourth program module operates only when a state change occurs by comparing the current state with the previous state of the switch stored in the database.

The input factor of the fourth program module is the setting contents (REQUEST BODY) for performing the action or recovery operation, and it is recyclable so that the setting command of other operations as well as the action and recovery operation can be performed according to the setting contents.

And it goes without saying that the fourth program module can also perform the redundant response technique three times in case the command request fails.

In FIG. 2 , the network management apparatus 100 is configured as separate hardware independent of each SDN controller 200 as an example, but as described above, the function of the network management apparatus 100 according to an embodiment of the present invention is Since it may be configured as one program module, it goes without saying that it may be configured on the same hardware as the SDN controller 200 .

Meanwhile, it goes without saying that the process of performing each of the above-described embodiments may be performed by a program or application stored in a predetermined recording medium (eg, computer-readable). Here, the recording medium includes an electronic recording medium such as a random access memory (RAM), a magnetic recording medium such as a hard disk, and an optical recording medium such as a compact disk (CD).

In this case, the program stored in the recording medium may be executed on hardware such as a computer or a smart phone to perform each of the above-described embodiments. In particular, at least one of the functional blocks of the network management apparatus 100 according to the present invention described above may be implemented by such a program or an application.

In addition, the present invention is not limited to the specific embodiments described above, but can be practiced with various modifications and modifications within the scope without departing from the gist of the present invention. It will be apparent that such modifications and variations are included in the present invention provided they fall within the scope of the appended claims.

100: network management device 200: SDN controller
300: SDN packet processing unit 110: information collection unit
120: state information comparison unit 130: control request unit
140: storage

Claims (14)

A control method performed by a network management device, comprising:
(a) requesting and receiving at least one SDN (Software Defined Network) packet processing device and an SDN controller that communicates with each SDN packet processing device to collect status information;
(b) comparing the state information of each SDN packet processing device received from the SDN controller in step (a) with previously stored state information;
(c) selecting a case that does not match the result of the comparison in step (b) and then requesting the SDN controller to switch over or restore control to the corresponding SDN packet processing device; control method. According to claim 1,
Communication with the SDN controller is a control method of a network management device, characterized in that made by sending and receiving a message according to HTTP (HyperText Transfer Protocol). 3. The method of claim 2,
Giving a serial number to a transmission message during communication with the SDN controller, and retransmitting a transmission message corresponding to the missing serial number when receiving a serial number missing message from the SDN controller A control method for a network management device. 3. The method of claim 2,
The control method of a network management device, characterized in that the same message is transmitted a preset number of times at a preset time interval during communication with the SDN controller. According to claim 1,
In step (c), when the status information for a specific SDN packet processing device is changed from 'operational status' to 'failure status' as a result of the comparison in step (b), ' A control method of a network management device, characterized in that transmitting a request message for making a packet path detour to another SDN packet processing device maintained in an 'operational state' to the SDN controller. 6. The method of claim 5,
In step (c), when the status information on the specific SDN packet processing device is changed from the 'failure status' to the 'operational status' as a result of the comparison in step (b), the corresponding specific SDN packet processing device is restored along with the corresponding information in step (c). and transmitting a request message to the SDN controller to restore the other SDN packet processing device, which has performed detour processing on a packet directed to a specific SDN packet processing device, to the SDN controller. A computer-readable recording medium in which a program for executing the method of any one of claims 1 to 6 is recorded. An application program stored in a computer-readable recording medium in combination with hardware to execute the method of any one of claims 1 to 6. an information collection unit for requesting and receiving state information collection of each SDN packet processing apparatus from an SDN controller communicating with at least one SDN (Software Defined Network) packet processing apparatus;
a state information comparison unit for comparing the state information of each SDN packet processing device received from the SDN controller by the request collection unit with pre-stored state information;
and a control requesting unit requesting the SDN controller to switch over or restore control to the corresponding SDN packet processing unit after selecting a case where the comparison result of the state information comparison unit does not match. 10. The method of claim 9,
Communication with the SDN controller is a network management device, characterized in that made by sending and receiving a message according to HTTP (HyperText Transfer Protocol). 11. The method of claim 10,
The information collection unit and the control request unit assign a serial number to a transmission message during communication with the SDN controller, and retransmit a transmission message corresponding to the missing serial number when a serial number missing message is received from the SDN controller. Network management device, characterized in that. 11. The method of claim 10,
The network management apparatus of claim 1, wherein the information collection unit and the control request unit transmit the same message a predetermined number of times at a predetermined time interval during communication with the SDN controller. 10. The method of claim 9,
As a result of the comparison of the status information comparison unit, the control request unit may change the status information for a specific SDN packet processing device from the 'operational state' to the 'failure state'. and transmitting a request message to the SDN controller to make a packet path detour to another SDN packet processing device maintained as . 14. The method of claim 13,
The control request unit, when the state information on the specific SDN packet processing unit is changed from the 'failure state' to the 'operational state' as a result of the comparison of the status information comparison unit, the control request unit may restore the specific SDN packet processing unit along with the specific SDN packet. and transmitting, to the SDN controller, a request message for restoring the other SDN packet processing device that has performed detour processing on the packet to the processing device.

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