KR20210051487A - Method for controlling replication of session and upf node performing method - Google Patents

Abstract

According to an embodiment of the present invention, a method for controlling copy of a session performed in a user plane function (UPF) node comprises a step of allowing a first UPF node to copy sessions, managed by the first UPF node, to a second UPF node. The copy step comprises the following steps of: determining whether an abnormal situation occurs during copy; and pausing the copy of the sessions for first time when the abnormal situation occurs.

Description

Method for controlling session replication and UPF node performing the method {METHOD FOR CONTROLLING REPLICATION OF SESSION AND UPF NODE PERFORMING METHOD}

The present invention relates to a method for controlling session replication and a UPF node performing the method.

In the LTE communication system, as the type of communication service and the transmission request speed are diversified, the LTE frequency expansion and the evolution to the 5G communication system are actively progressing.

This rapidly evolving 5G communication system accommodates as many terminals as possible based on limited radio resources, while eMBB (enhanced mobile broadband)/mMTC (massive machine type communications)/ It supports URLLC (ultra-reliable and low latency communications) scenarios.

In the 5G communication system, a network structure to support end-to-end terminals, base stations (access), cores and servers is defined, and a single node (e.g., S-GW, P-GW, etc.) in existing LTE (4G) A network structure that separates the functions of control signaling and data transmission/reception, which were performed in a complex manner, to separate the control signaling function area (or control area) (Control Plane) and the data transmission/reception function area (or user area) (User Plane). Is defined.

In this case, various nodes are included in the control plane. For example, the Access and Mobility Function (AMF) that controls access to the wireless section of the terminal, the PCF (Policy Control Function) that manages/controls policies such as terminal information and subscription service information for each terminal, and billing, and a session for using data services for each terminal. For example, a session management function (SMF) that manages/controls a device, a network exposure function (NEF) that shares information with an external network, and the like.

In addition, things such as UPF may be included in the user plane.

The problem to be solved of the present invention is a process for coping with an anomaly occurring during replication of sessions managed by UPF, and provides a method of pausing, interrupting, and restoring the replication of sessions. will be.

However, the problem to be solved of the present invention is not limited to those mentioned above, and another problem to be solved that is not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description. will be.

A method of controlling the replication of a session performed in a User Plane Function (UPF) node according to an embodiment of the present invention is in which a first UPF node replicates sessions managed by the first UPF node to a second UPF node. Including a step, wherein the step of duplicating may include: determining whether an abnormal situation occurs while performing the duplicating; And when an abnormal situation occurs, pausing the replication of the sessions for the first time period.

The step of determining whether the abnormal situation occurs may include a load state, an interface state and a QoS state of the first UPF node or the second UPF node, and a replication speed of the sessions and corresponding to the replicated sessions. It may be determined whether the abnormal situation occurs based on at least one of the data traffic transmission/reception speeds of the terminal.

The method includes the steps of re-determining whether the abnormal situation has occurred after the first time has elapsed; And when the abnormal situation has not been resolved, determining the interruption of replication of the sessions and restoration of the original state.

The method includes the steps of: requesting approval for the interruption of the replication and the execution of the restoration to the SMF (Session Management Function) node; And in response to the request, it may further include the step of receiving approval for the execution of the interruption of the replication and the restoration of the original state.

The method further includes transmitting a message to perform restoration to the second UPF node according to the determination, wherein the message to perform restoration to the restoration deletes some of the previously transmitted sessions by the second UPF node. Can be used to

The sessions may be grouped into one session set and transmitted at a time.

The first UPF includes a plurality of virtualized first UPF instances, the second UPF includes a plurality of virtualized second UPF instances, and the replicating may include any one of the plurality of first UPF instances. Sessions managed by one may be replicated to any one of the second UPF instances.

The method further includes determining an order of transmitting the sets based on the monitored information, and the monitoring information includes: a processing speed and a resource state of the first UPF node and the second UPF node, and the second It may include at least one of a bandwidth between 1 UPF and the second UPF 200b and a transmission rate required for a session to be duplicated.

According to another embodiment of the present invention, a User Plane Function (UPF) node for controlling the replication of a session may include a transceiver for transmitting and receiving signals with other UPF notes and SMF (Session Management Function) nodes; And a processor for controlling the transceiver, wherein the processor performs replication for sessions managed by the UPF node, determines whether an abnormal situation occurs during replication, and if an abnormal situation occurs, the Replication of the sessions can be paused for 1 hour.

According to an embodiment of the present invention, when an abnormality occurs in performance and quality during the UPF replication process, by providing a method of temporarily stopping, stopping, and restoring the replication, it is possible to effectively cope with the abnormality occurring in the UPF replication process. I can.

1 is a diagram showing an excerpt of a part of the architecture of a 5G system according to an embodiment.
FIG. 2 exemplarily shows a configuration of an SMF according to an embodiment.
3 exemplarily illustrates a configuration of a UPF according to an embodiment.
4 exemplarily illustrates a copying ordering set according to an embodiment.
5 exemplarily illustrates a procedure of a UPF duplication process according to an embodiment.
6 exemplarily illustrates a procedure for performing restoration to an original state due to an abnormal situation occurring during a duplication process according to an embodiment.
7 illustrates a configuration of a UPF including a plurality of UPF instances according to an embodiment.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and the general knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims.

In describing embodiments of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. In addition, terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to the intention or custom of users or operators. Therefore, the definition should be made based on the contents throughout the present specification.

FIG. 1 shows an excerpt of a part of the architecture 10 of a 5G system according to an embodiment.

The 5G system itself of the architecture 10 shown in FIG. 1 will be described. The 5G system is an advanced technology from the 4th generation LTE mobile communication technology. This 5G system is an expanded technology of new radio access technology (RAT, Radio Access Technology) and LTE (Long Tern Evolution) through an evolution of the existing mobile communication network structure or a clean-state structure. (extended LTE), non-3GPP access, etc. are supported.

However, since the architecture 10 shown in FIG. 1 is only exemplary, it is not construed that the idea of the present invention is limited to that shown in FIG. 1, and the idea of the present invention is applied only to a 5G system. It is not interpreted as being.

The architecture 10 includes various components (ie, network functions (NF)). For example, an access and mobility management function (AMF: (Core) Access and Mobility Management Function) 300, a session management device (SMF: Session Management Function) 100, a policy control function (PCF: Policy Control function) 400, and A plurality of user plane devices (a first UPF and a second UPF, and a user plane function (UPF) 200a and b) are shown. Here, the two UPFs 200, such as the first UPF 200a and the second UPF 200b, are shown to be included in the architecture 10, which is only exemplary. That is, depending on the embodiment, not only two UPFs 200 but at least three may be included in the architecture 10. In addition, although not shown in FIG. 1, the architecture 10 may include a data network (DN) or a (wireless) access network ((R)AN: (Radio) Access Network, or a base station).

AMF (300), SMF (100), PCF (400), the first UPF (200a) and the second UPF (200b) by an interface referred to as a service-based architecture (service-based architecture (SBA) 500). Are connected to each other. Here, according to an embodiment, the SMF 100 may be connected to each of the first and second UPFs 200a and b by an N4 interface (not shown in FIG. 1), but hereinafter, the SBA ( 500), among others, it will be explained on the premise that it is connected by Nupf.

Among them, the SMF 100 is a component belonging to a control plane in the 5G system. In addition, UPF (200a, b,) is a component belonging to the user plane (user plane).

In the process of operating the UPF 200, a copy (migration or copying) of the UPF 200 may be requested depending on the situation. For example, when requested by another network function (NF) belonging to the architecture 500, when the terminal enters a specific area, according to the policy of the PCF, when the terminal is handed over, replication of the UPF 200 may be requested. have. Alternatively, a replication of the UPF 200 may be requested in the process of replacing H/W or S/W related to the UPF 200, increasing capacity, or troubleshooting. In addition, the SMF 100 may directly determine the need to duplicate the UPF 200 so that the UPF 200 is duplicated. For example, the SMF 100 may determine the need for replication in real time based on at least one of a load state, an interface state, and a QoS state for each of the first UPF 200a and the second UPF 200.

Here, the load state refers to the amount of session load that the UPF 200 bears (the number of active sessions, the number of idle sessions, the maximum number of sessions) UPF such as throughput or latency. It may include at least one of a processing speed of 200 and a resource state (CPU resource, memory resource, and storage resource) of the UPF 200, but is not limited thereto.

In addition, the interface status refers to a message type (Service Name, Service Operation, Attribute Name) constituting an interface (SBA interface (Nupf) or N4 interface) connected to the UPF 200, and a message communication method (request/response and subscribe/notify). ) Based on network functions (NF), such as latency, throughput, and error conditions.

In addition, QoS status refers to the status of usage data/packet amount information for user plane session processing, which UPF 200 is processing for subscribers, speed information, delay information, error information, etc. for each of the uplink or downlink. It may include.

On the other hand,'UPF duplication' means all the things that the existing UPF has, for example, all customer sessions handled by the existing UPF, or packet detection rule (PDR), forward action rule (FAR), and QoS enforcement (QER) related to these sessions. rule) and URR (usage report rule) are transferred (migration or copy) to other UPFs with the same identity. If the existing UPF, which processes a total of 100,000 subscribers' sessions at 10Gb/s, is replicated to another UPF, the other UPFs can also process a total of 100,000 subscribers' sessions at 10Gb/s.

Hereinafter, each of the SMF 100 and UPF 200a and b involved in the replication of the UPF will be described in detail.

2 shows the configuration of the SMF 100 according to an embodiment.

Referring to FIG. 2, the SMF 100 includes a copy preparation unit 110, a copy order setting unit 120, and a locking unit 130, but the configuration of the SMF 100 is limited to that shown in FIG. It is not interpreted.

In FIG. 2, for convenience of explanation, the copy preparation unit 110, the copy order setting unit 120, and the locking unit 130 are shown as being configured in the form of physical hardware in the SMF 100, but are not limited thereto. Does not. That is, according to the embodiment, the copy preparation unit 110, the copy order setting unit 120, and the locking unit 130 are merely conceptually divided in order to easily describe a program or process performed by the SMF 100, These can also be implemented as a series of instructions included in one program.

First, the SMF 100 may be generated according to a network virtualization function (NFV).

The duplication preparation unit 110 determines the necessity of duplication for the session of the first UPF 200a. As described above, the necessity of replication is determined according to whether a request from another network function (NF) belonging to the architecture 500 is received, or a load for each of the first UPF 200a and the second UPF 200 It may be determined based on at least one of a state, an interface state, and a QoS state. Here, for each of the load state, the interface state, and the QoS state, what has been described above will be used.

When it is determined that there is a need for duplication by the duplication preparation unit 110, the duplication preparation unit 110 requests each of the first UPF 200a and the second UPF 200b to prepare for duplication. Preparation for copying is also referred to as copy association.

Looking specifically at the preparation for copying, the copy preparation unit 110 requests the first UPF 200a to prepare for copying. In this process, the replication preparation unit 110 may deliver the following message to the first UPF 200a.

-setup (initiation), transfer, address of the second UPF (200b)

Let's take a look at the above message. Setup (initiation) is to instruct the first UPF 200a to initiate replication. Transfer indicates that the first UPF 200a is a transmitting entity of the session. The second UPF 200b address represents a destination address, that is, a destination address to which the first UPF 200a transmits its session.

On the other hand, the copy preparation unit 110 may generate the following matters as a'copy rule' in the process of requesting the copy preparation. The generated duplication rule is transmitted to the first UPF 200a.

Threshold of time spent on replication

Whether to keep or delete information (eg, session information) of the first UPF 200a upon completion of duplication

Whether the information of the first UPF 200a is compressed and transmitted to the second UPF 200b during the duplication process

Here, the threshold of time required for replication may be a criterion for determining whether to perform replication. For example, if the estimated time required for replication exceeds the above-described threshold, replication from the first UPF 200a to the second UPF 200b may not be performed. Alternatively, if the actual time taken after the duplication is started exceeds the above-described threshold, the duplicated content may be rolled back from the first UPF 200a to the second UPF 200b, so that the duplication may not proceed any more. .

In addition, the replication preparation unit 110 requests the second UPF 200b to prepare for replication as well. In this process, for example, the replication preparation unit 110 may deliver the following message to the second UPF 200b.

-setup(initiation), receive, address of the first UPF (200a)

Let's take a look at the above message. The setup (initiation) is to instruct the second UPF 200b to initiate replication. Receive indicates that the second UPF 200b is a receiving subject of the session (ie, a subject to which the session will be duplicated). The first UPF 200a address indicates a source address to which the second UPF 200b will receive a session.

The replication order setting unit 120 sets a replication order for a session that is a replication target. The set replication order is transmitted to the first UPF 200a.

Here, all the sessions of the first UPF 200a may be the target of replication, or only some of the sessions may be the target of replication. If all the sessions of the first UPF 200a are to be copied, the copy order setting unit 120 sets the copy order for all these sessions. On the other hand, if only some of the sessions are to be replicated, the replication order setting unit 120 sets the replication order for only some of these sessions.

The replication order setting unit 120 may set a replication order for each session. For example, when there are 500 sessions, the replication order setting unit 120 may set different replication orders for each of the 500 sessions.

However, unlike setting the replication order for each session, according to an embodiment, the replication order setting unit 120 may classify the session into any one of a plurality of sets, and then set the replication order for each set. For example, the replication order setting unit 120 classifies sessions 1 to 100 as set 1, 101 to 200 sessions as set 2, and 201 to 300 sessions as set 3, and then set 3->set 1- You can also set the replication order in the order of >set 2.

Here, when classifying a session into any one of a plurality of sets, a slice ID (IDentification) of each session may be referred to. In addition, when setting the replication order for each set, slice IDs of sessions included in the corresponding set may also be referenced.

The locking unit 130 prevents further updating of a session in which replication is being performed. As will be described later, the SMF 100 receives information on which session replication is being performed from the first UPF 200a, and the locking unit 130 does not update the session currently being replicated based on this information. To avoid locking. In addition, the SMF 100 is provided with information on which session has been copied from the first UPF 200a, and the locking unit 130 releases the lock processing for the session for which the copy has been completed based on this information ( release).

Next, the first UPF 200a will be described. The first UPF 200a refers to a UPF that copies its own session to another UPF.

3 illustrates a configuration of a first UPF 200a according to an embodiment.

Referring to FIG. 3, the first UPF 200a includes a copy preparation unit 210, a monitoring unit 220, a detailed copy order setting unit 230, a copy execution unit 240, and a copy method adjustment unit 250. However, the configuration of the UPF 200 is not limited to that illustrated in FIG. 3.

In FIG. 3, for convenience of explanation, the replication preparation unit 210, the monitoring unit 220, the replication order detail setting unit 230, the replication execution unit 240, and the replication method adjustment unit 250 are provided within the UPF 200a. Although shown as being configured in the form of physical hardware, it is not limited thereto. That is, according to the embodiment, the replication preparation unit 210, the monitoring unit 220, the replication order detail setting unit 230, the replication execution unit 240, and the replication method adjustment unit 250 are performed in the UPF (200a). It is merely conceptually divided in order to easily describe a program or process, and these may be implemented as a series of instructions included in one program. Accordingly, information on the replication preparation unit 210, the monitoring unit 220, the detailed replication order setting unit 230, the replication execution unit 240, and the replication method adjustment unit 250 is mounted on the first UPF 200a. It is stored in a memory, is performed by a processor mounted on the first UPF 200a, and transmission/reception may be performed by a transceiver mounted on the first UPF 200a.

First, the first UPF 200a may be generated according to a network virtualization function (NFV).

The replication preparation unit 210 performs replication preparation. Such replication preparation may be in accordance with a request received from the SMF 100 by the first UPF 200a.

Looking specifically at the preparation for replication, the replication preparation unit 210 receives the following message from the SMF (100).

-setup (initiation), transfer, address of the second UPF (200b)

Since the above message has already been described in the section for the SMF 100, the description section will be used.

Meanwhile, the replication preparation unit 210 may additionally receive the following message from the SMF 100. This information will be described later, but may be considered by the replication performing unit 240.

Threshold of time spent on replication

Whether to keep or delete information (eg, session information) of the first UPF 200a upon completion of duplication

Whether the information of the first UPF 200a is compressed and transmitted to the second UPF 200b during the duplication process

The replication preparation unit 210 receiving the above message from the SMF 100 transmits a message for preparation of replication to the second UPF 200b. In this process, for example, the replication preparation unit 210 may deliver the following message to the second UPF 200b.

-setup(copy)

Let's take a look at the above message. setup(copy) is to instruct the second UPF 200b to prepare for copying. Upon receiving such a message, the second UPF 200b may check and secure a resource (resource) required for replication.

The monitoring unit 220 may monitor the states of each of the first UPF 200a and the second UPF 200b in real time. Here, the state to be monitored is, for example, the amount of session load (the number of active sessions, the number of idle sessions, the maximum number of sessions), the throughput and the latency of the UPF 200. It may be at least one of a processing speed and a resource state of the UPF 200, a characteristic of the base station (R)AN, a bandwidth between the first UPF 200a and the second UPF 200b, and a transmission rate of a session.

In addition, the monitoring unit 220 is the rate at which the session (or session set) is replicated from the first UPF 200a to the second UPF 200b and/or the communication quality of the terminal corresponding to the replicated session (e.g., data traffic transmission/reception). Speed) can be further monitored. The state monitored by the monitoring unit 220 will be described later, but it may be referred to in detail setting of the replication order or adjusting the replication method, and the speed at which the monitored session (or set of sessions) is replicated and/or the session to be replicated Whether or not the communication quality (eg, data traffic transmission/reception speed) of the terminal corresponding to is deteriorated may be referred to when the first UPF 200a decides to pause or stop replication.

The replication order detail setting unit 230 sets the replication order for the session in detail. In this process, the replication order detail setting unit 230 uses the above-described information on the replication order received from the SMF 100.

Let's look at it in more detail. The information on the replication order transmitted from the SMF 100 includes a result of classification so that each of at least one session is included in any one of a plurality of sets, and information on a replication order between the plurality of sets. The duplication order detail setting unit 230 subdivides and sets the duplication sequence between sessions included in any one set for each of a plurality of sets according to a predetermined criterion. For example, it is assumed that the first UPF 200a has received the following replication order from the SMF 200.

Sessions 1 through 100 are set 1, and the replication order for set 1 is the second.

Sessions 101 through 200 are set 2, and the replication order for set 2 is the third.

Sessions 201 through 300 are set 3, and the replication order for set 3 is the first.

The replication order detail setting unit 230 classifies sessions 1 to 100 included in set 1 into sessions 1 to 30, 31 to 60, and 61 to 100, You can set the replication order in detail first, from 61 to 100 next, and from 31 to 60 last. For Set No. 2 and Set No. 3, the duplication order can be set in detail in the same manner.

Here, when setting the replication order in detail, the replication order detail setting unit 230 may refer to a slice ID of each session or each of the items monitored by the monitoring unit 220 in real time. Items monitored in real time by the monitoring unit 220 include load status, interface status and QoS status for each of the first UPF 200a and the second UPF 200, and the first UPF 200a and the second Bandwidth between UPF (200b), characteristics of base station ((R)AN), number of active sessions, number of idle sessions, and real-time resource status of the first UPF (200a) and the second UPF (200b) At least one of (CPU, memory, I/F, etc.) may be included.

The replication performing unit 240 may perform replication for a session (or a set of sessions). The replication performing unit 240 may transmit a session (or a session set) to be replicated in the determined replication order to the second UPF 200b.

The replication performing unit 240 may determine whether an abnormal situation has occurred during the replication process. In other words. In the replication process, when the monitoring unit 220 monitors that the speed at which the session (or session set) is replicated is less than the reference value or that the data traffic transmission/reception speed of the terminal corresponding to the replicated session has dropped below the threshold value, replication is performed. The unit 240 may temporarily stop duplication. According to an embodiment, the duplication execution unit 240 may set a time to pause and transmit a pause request message including information on the set time to the second UPF 200b.

Even after the set time elapses, if the speed at which the session (or session set) is replicated is still less than the reference value or the data traffic transmission/reception speed of the terminal corresponding to the replicated session is less than or equal to the threshold value, the replication performing unit 240 stops the replication, Information indicating that replication has been stopped may be transmitted to the second UPF 200b.

When receiving information indicating that the duplication has been stopped, the second UPF 200b may roll back (delete) the already copied content from the first UPF 200a. Depending on the embodiment, the second UPF 200b may roll back only the session set that has not been transmitted (transmitting), or all or part of the session sets received according to the replication request received from the first UPF 200a. You can also roll back.

4 exemplarily illustrates a copying ordering set according to an embodiment.

Referring to FIG. 4, the replication order 131 transmitted from the SMF 100 to the first UPF 200a depends on what sets a plurality of sessions are included in and the replication order of each set based on the slice ID. Information is included. In addition, it can be seen that the replication order 241 set in detail by the first UPF 200a is further subdivided into the replication order 131.

Referring back to FIG. 3, the replication execution unit 240 sequentially replicates at least one session to the second UPF 200b in a'set unit' according to the replication order set by the replication order detail setting unit 230. Let it. In this case, “by set” is replicated means that sessions included in any one set are “bulky”.

On the other hand, when replication is performed, the PDR may be replicated last among the packet detection rule (PDR), forward action rule (FAR), QoS enforcement rule (QER), and usage report rule (URR) constituting the session. This is because in the case of PDR, FAR, QER, and URR must be prepared in advance to be able to replicate, and in general, the rules for FAR, QER, and URR are significantly smaller than the number of sessions.

The replication method adjustment unit 250 adjusts the replication method performed by the replication execution unit 240. For example, the replication method adjustment unit 250 adjusts the replication order or adjusts the number of sessions included in each set. In this adjustment, the replication method adjustment unit 250 may refer to the items monitored by the monitoring unit 220. For example, the replication method adjustment unit 250 includes a bandwidth between the first UPF 200a and the second UPF 200b, which are monitored by the monitoring unit 220, characteristics of the base station (R)AN, and an active session. The above-described replication method can be adjusted by referring to the number of and idle sessions.

Meanwhile, the replication execution unit 240 may consider the following message received from the SMF 100 by the replication preparation unit 210 in performing replication.

Threshold of time spent on replication

Whether to keep or delete information (eg, session information) of the first UPF 200a upon completion of duplication

Whether the information of the first UPF 200a is compressed and transmitted to the second UPF 200b during the duplication process

Let's look at each of them. For example, the replication execution unit 240 may not perform replication from the first UPF 200a to the second UPF 200b when the estimated time required for replication exceeds the above-described threshold. Alternatively, if the actual time taken after the duplication starts exceeds the above-described threshold, the duplication execution unit 240 may roll back the already duplicated content from the first UPF 200a to the second UPF 200b. You may not proceed with the cloning any more.

In addition, the duplication performing unit 240 may delete or maintain information such as session information of the first UPF 200a when duplication is completed, referring to the above-described message.

In addition, the replication performing unit 240 compresses the information of the first UPF 200a in the replication process and transmits the compressed information to the second UPF 200b, or transmits the compressed information to the second UPF 200b in an uncompressed state, referring to the above-described message. ).

As described above, according to an embodiment, the process of preparing the replication of the UPF and the actual replication process may be performed under interworking between the UPF and the SMF, and in this process, the service is provided to the customer in the same manner before and after the UPF replication. Can be provided.

FIG. 5 exemplarily illustrates a procedure of a cloning process of the first UPF 200a according to an embodiment.

However, FIG. 5 is merely an example, and the spirit of the present invention is not limited to that illustrated in FIG. 5. The cloning process of the first UPF 200a can be performed by interlocking the first UPF 200a, the second UPF 200b, and the SMF 100.

Referring to FIG. 5, the SMF 100 determines the necessity of copying the first UPF 200a (S100). The need for replication may be based on triggering that is requested for replication from another network function (NF) belonging to the architecture 500 as described above. Alternatively, the need for replication may be determined by the SMF 100 in real time based on at least one of a load state, an interface state, and a QoS state for each of the first UPF 200a and the second UPF 200. Here, for each of the load state, the interface state, and the QoS state, the foregoing description will be used.

If it is determined that there is a need for replication for the first UPF 200a, the SMF 100 requests each of the first UPF 200a and the second UPF 200b to prepare for replication.

Looking specifically at the preparation for copying, the copy preparation unit 110 of the SMF 100 requests the first UPF 200a to prepare for copying (S110). As described above, in this process, for example, the replication preparation unit 110 can deliver the following message to the first UPF 200a.

-setup (initiation), transfer, address of the second UPF (200b)

Meanwhile, in step S110, the replication order for the session in which the SMF 100 is set may be transmitted to the first UPF 200a. The replication order transmitted in step S110 is set by the replication order setting unit 120 of the SMF 100.

Regarding the replication order, the replication order setting unit 120 may classify the session into any one of a plurality of sets, and then set the replication order for each set.

The replication preparation unit 110 of the SMF 100 also requests the second UPF 200b to prepare for replication (S111). As described above, in this process, for example, the replication preparation unit 110 can deliver the following message to the second UPF 200b.

-setup(initiation), receive, address of the first UPF (200a)

The first UPF 200a, which has completed the preparation for replication, transmits a copy preparation complete message to the SMF 100 (S200), and the second UPF 200b, which has completed preparation for replication, also sends a copy preparation complete message to the SMF 100. Transmit (S300).

Meanwhile, the first UPF 200a also requests the second UPF 200b to prepare for replication (S201). In this process, for example, the replication preparation unit 210 of the replication first UPF 200a can deliver the following message to the second UPF 200b as described above.

-setup(copy)

In response to the replication preparation request in step S201, the second UPF 200b secures resources required for replication, and then transmits a replication preparation completion message to the first UPF 200a (S301).

When the replication preparation is completed, the replication order detail setting unit 230 of the first UPF 200a sets the replication order for the session in detail (S202). Let's look at it in more detail. The information on the replication order received from the SMF 100 by the first UPF 200a is classified so that each of the at least one session is included in any one of the plurality of sets, and the replication order between the plurality of sets. Includes information about. The duplication order detail setting unit 230 subdivides and sets the duplication sequence between sessions included in any one set for each of a plurality of sets according to a predetermined criterion. For example, it is assumed that the first UPF 200a has received the following replication order from the SMF 200.

Sessions 1 through 100 are set 1

Sessions 101 through 200 are set 2

Sessions 201 through 300 are set 3

The order of replication is set 3->set 1->set 2.

The replication order detail setting unit 230 classifies sessions 1 to 100 included in set 1 into sessions 1 to 30, 31 to 60, and 61 to 100, and then selects from 1 to 30. First, you can set the order of replication from 61 to 100, then 31 to 60, last. The same is true for set 2 and set 3.

Here, when setting the replication order in detail, the replication order detailed setting unit 230 refers to the slice ID of each session or the monitored information by the monitoring unit 220 of the first UPF 200a in real time. I can. Matters that are monitored in real time by the monitoring unit 220 will use the foregoing.

Thereafter, the first UPF 200a transmits a message indicating that the preparation for copying of the first session set among the plurality of session sets is completed to the SMF 100 (S203).

Upon receiving the message of step S203, the SMF 100 locks the first session set so that it is not updated (S120).

In addition, the replication execution unit 240 of the first UPF 200a transfers the first session set to the second UPF 200b (S204), and the second UPF 200b transmits the first session set received in step S204. Replication is performed (S302).

When the duplication is completed, the second UPF 200b transmits a message indicating that the duplication has been completed to the SMF 100 (S303), and the SMF 100 transmits an OK response to this to the second UPF 200b (S121). ).

Upon receiving the OK response in step S121, the second UPF 200b transmits the OK response to the first UPF 200a (S303).

Thereafter, replication of a session set to be replicated next to the first session set is started (S205). In FIG. 5, it is shown that replication is performed for the second set of sessions.

6 exemplarily illustrates a procedure for performing restoration to an original state due to an abnormal situation occurring during a duplication process according to an embodiment.

However, FIG. 6 is merely an example, and the spirit of the present invention is not limited to that illustrated in FIG. 6. The restoration process of the first UPF 200a may be performed by interlocking the first UPF 200a, the second UPF 200b, and the SMF 100.

From the process in which the SMF 100 determines the necessity of replication for the first UPF 200a (S100), the replication execution unit 240 of the first UPF 200a delivers the first session set to the second UPF 200b Until the process (S204) is the same as described in FIG. Therefore, a description of the above processes will be omitted.

The replication execution unit 240 of the first UPF 200a performs replication on the first session set, and may determine whether an abnormal situation has occurred during the replication process (S206). Here, the criterion for determining the abnormal situation is a load state, an interface state and a QoS state for the first UPF 200a and/or the second UPF 200, and the replication speed and the replication of the first session set. It may be one or more of data traffic transmission/reception speeds of the terminal corresponding to the first session set. For example, when the replication speed of the first session set is less than the reference value or the data traffic transmission/reception speed of the terminal corresponding to the first session set to be replicated is lower than the threshold value, the replication performing unit 240 of the first UPF 200a It can be determined that an abnormal situation has occurred during the duplication process.

When it is determined that an abnormal situation has occurred, the replication execution unit 240 of the first UPF 200a may set a pause time and pause the replication for the set pause time. The replication execution unit 240 of the first UPF 200a may transmit a pause request message including information on the pause time to the second UPF 200b (S207). The pause request message may include ID information indicating that the target of the pause is a first session set.

When the set pause time has elapsed, the replication execution unit 240 of the first UPF 200a may resume delivery of the first session set.

After retransmitting the first session set, the replication performing unit 240 of the first UPF 200a may determine whether the abnormal situation has been resolved (or whether the abnormal situation cannot be resolved) (S208). At this time, even after restarting the delivery of the first session set, if the speed at which the first session set is replicated is still less than the reference value or the data traffic transmission/reception speed of the terminal corresponding to the first session set to be replicated is less than the threshold, the first UPF 200a ) Decides to stop the replication, and transmits the original restoration request to the SMF 100 to stop the replication and restore the original state before the replication (S209). The original state restoration request may include ID information indicating that the object of the original state restoration request is a first session set.

In addition, according to an embodiment, after re-delivery of the first session set, as an abnormal situation occurs, the replication execution unit 240 of the first UPF 200a may pause the replication again. If the number of pauses is greater than the reference value, the replication execution unit 240 of the first UPF 200a decides to stop the replication, stops the replication, and makes a request to restore the original state to the original state before the SMF 100 Can be transferred to.

In response to the original restoration request, the SMF 100 may transmit, to the first UPF 200a, approval for restoration of the original state, which approves the stop of replication and restoration of the original state (S131). Depending on the embodiment, in the case of approving the replication interruption and restoration to the original state, the SMF 100 may notify other network function nodes (e.g., NEF, AF, UDM, PCF, NRF, NSSF, etc.) of the replication interruption and restoration to the original state. Can be (S132).

When receiving the original restoration approval from the SMF 100, the first UPF 200a may transmit information on the execution of the restoration to the second UPF 200b indicating that the restoration to the original condition is performed (S210). . The information on performing the restoration to the original state may include ID information indicating that the object to be restored to the original condition is a first session set.

According to an embodiment, the first UPF 200a may transmit a notification of restoration to the SMF 100 instead of a request for restoration of the original state. When notifying the restoration of the original state, the first UPF 200a may immediately transmit information on the execution of the restoration to the second UPF 200b without waiting for approval from the SMF 100.

When receiving information on performing the restoration, the second UPF 200b may cancel the context for the first session set (S304). That is, the second UPF 200b may delete the already duplicated content from the first session set.

When the original state restoration is completed, the first UPF 200a may transmit the original state restoration completion indicating that the original state restoration is completed to the SMF 100 (S211).

7 illustrates a configuration of a UPF including a plurality of UPF instances according to an embodiment.

Referring to FIG. 7, a first UPF 200a includes a plurality of UPF instances 261a, 262a, 263a, and a second UPF 200b includes a plurality of UPF instances 261b, 262b, 263b. can do. In FIG. 4, for convenience of description, each UPF is illustrated as including three UPF instances, but is not limited thereto.

Each of the plurality of UPF instances 261a, 262a, 263a, 261b, 262b, and 263b included in the first UPF 200a and the second UPF 200b may perform all or part of the functions of the UPF. That is, each UPF instance identifies a packet and a packet detection rule (PDR) for matching the identified packet with a specific processing rule, and a forwarding behavior rule for forwarding/deleting/buffering/duplicating the identified packet ( Forwarding Action Rule, FAR), Gating and QoS control, QoS Enforcement Rule (QER) to provide flow and service level indication, and calculate/report traffic processed by UPF, and CHF In order to activate the billing function, the entire usage reporting rule (URR) for generating a report can be processed, or at least one of PDR, FAR, QER, and URR can be performed.

Each UPF instance can handle at least one session.

Depending on the embodiment, the UPF instance may be a virtualized processor or server, and may be a physically existing processor or server.

Each UPF instance may have different IDs, addresses, capabilities, and/or resources (CPU, memory, I/O, etc.). That is, the UPF may configure each UPF instance according to the usage type and/or the function to be performed.

The process for UPF replication described with reference to FIGS. 2 to 6 may also be applied to UPF instances.

That is, the SMF 100 determines the necessity of replicating all or part of the UPF instance (eg, the first instance 261a) included in the first UPF 200a, and replicating the first instance 261a. If it is determined that there is a need, the SMF 100 requests each of the first UPF 200a and the second UPF 200b to prepare for replication. In this case, the replication preparation transmitted by the SMF 100 to the first UPF 200a may include information indicating a UPF instance (eg, the first instance 261a) to be replicated in the first UPF 200a.

The SMF 100 may classify the sessions processed in the first UPF instance 261a into at least one set, and then transmit the replication order for each set to the first UPF 200a.

The SMF 100 may also request the second UPF 200b to prepare for replication. The replication preparation transmitted by the SMF 100 to the second UPF 200b may include the address of the UPF instance (eg, the first instance 261a) to which the session (set of sessions) is to be delivered. According to an embodiment, the preparation for replication transmitted by the SMF 100 to the second UPF 200b includes the address of the UPF instance (eg, the second instance 210b) in the second UPF to which the session (set of sessions) is to be replicated. It may contain more.

According to an embodiment, when the replication preparation is completed, the first UPF 200a may set the replication order for sessions processed in the first UPF instance 261a in detail. That is, the first UPF 200a may once again group the sessions within the set of sessions, and replicate the grouped sessions in an order according to a predetermined criterion. The first UPF 200a may group sessions in detail by referring to a slice ID (IDentification) of each session or monitored information in real time, and may determine a replication order.

Thereafter, the first UPF 200a delivers the first set of sessions to the second UPF 200b among the sets of sessions processed by the first UPF instance 261a, and the second UPF 200b transmits the received first session set to the second UPF 200b. One session set may be duplicated to the second UPF instance 261b.

Meanwhile, in the process of replicating the first session set to the second UPF instance 261b, the speed at which the first session set is replicated is less than or equal to the reference value, or the data traffic transmission/reception speed of the terminal corresponding to the first session set is less than the threshold. When it is monitored that it has been degraded to, the first UPF 200a may pause the replication. According to an embodiment, the first UPF 200a may set a time to pause and transmit a pause request message including information on the set time to the second UPF 200b.

Even after the set time elapses, if the speed at which the first session set is replicated is still less than the reference value or the data traffic transmission/reception speed of the terminal corresponding to the first session set is less than the threshold value, the first UPF 200a is the first session set. It is possible to stop the copying of and transmit information indicating that the copying has been stopped to the second UPF 200b.

When receiving information indicating that the duplication has been stopped, the second UPF 200b may roll back (delete) the already duplicated content in the first session set.

Combinations of each block of the block diagram attached to the present invention and each step of the flowchart may be performed by computer program instructions. Since these computer program instructions can be mounted on the encoding processor of a general-purpose computer, special purpose computer or other programmable data processing equipment, the instructions executed by the encoding processor of the computer or other programmable data processing equipment are each block of the block diagram or Each step in the flow chart will create a means to perform the functions described. These computer program instructions can also be stored in computer-usable or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement a function in a particular way, so that the computer-usable or computer-readable memory. It is also possible to produce an article of manufacture in which the instructions stored in the block diagram contain instruction means for performing the functions described in each block of the block diagram or each step of the flowchart. Since computer program instructions can also be mounted on a computer or other programmable data processing equipment, a series of operating steps are performed on a computer or other programmable data processing equipment to create a computer-executable process to create a computer or other programmable data processing equipment. It is also possible for the instructions to perform the processing equipment to provide steps for executing the functions described in each block of the block diagram and each step of the flowchart.

In addition, each block or each step may represent a module, segment, or part of code that contains one or more executable instructions for executing the specified logical function(s). In addition, it should be noted that in some alternative embodiments, functions mentioned in blocks or steps may occur out of order. For example, two blocks or steps shown in succession may in fact be performed substantially simultaneously, or the blocks or steps may sometimes be performed in the reverse order depending on the corresponding function.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential quality of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: SMF
200: UPF
300: AMF
400: PCF

Claims (18)

In a method of controlling the replication of a session performed in a UPF (User Plane Function) node,
A first UPF node replicating sessions managed by the first UPF node to a second UPF node,
The step of replicating,
Determining whether an abnormal situation occurs while performing the duplication; And
In case an abnormal situation occurs, including the step of pausing the replication of the sessions for a first time
How to control the replication of sessions. The method of claim 1,
The step of determining whether the abnormal situation occurs,
Based on at least one of a load state, an interface state and a QoS state of the first UPF node or the second UPF node, and a replication rate of the sessions and a data traffic transmission/reception rate of a terminal corresponding to the replicated sessions To determine whether the abnormal situation has occurred
How to control the replication of sessions. The method of claim 1,
Determining whether the abnormal situation occurs again after the first time has elapsed; And
If the abnormal situation is not resolved, further comprising the step of determining the interruption and restoration (restoration) of the replication of the sessions
How to control the replication of sessions. The method of claim 3,
Requesting approval for the interruption of the replication and the execution of the restoration to the SMF (Session Management Function) node; And
In response to the request, further comprising the step of receiving approval for the execution of the interruption of the duplication and the restoration of the original state.
How to control the replication of sessions. The method of claim 3,
In accordance with the determination, further comprising transmitting a message to perform restoration to the second UPF node,
The original restoration performance message is used by the second UPF node to delete some of the previously transmitted sessions.
How to control the replication of sessions. The method of claim 1,
The sessions are grouped into one session set and transmitted at a time.
How to control the replication of sessions. The method of claim 1,
The first UPF includes a plurality of virtualized first UPF instances,
The second UPF includes a plurality of virtualized second UPF instances,
The step of replicating,
Replicating sessions managed by any one of the plurality of first UPF instances to any one of the second UPF instances
How to control the replication of sessions. The method of claim 1,
Further comprising determining an order of transmitting the sets based on the monitored information,
The monitoring information,
Including at least one of a processing speed and a resource state of the first UPF node and the second UPF node, a bandwidth between the first UPF and the second UPF 200b, and a transmission rate required for a session to be duplicated.
How to control the replication of sessions. In the UPF (User Plane Function) node that controls the replication of the session,
A transceiver for transmitting and receiving signals with other UPF notes and SMF (Session Management Function) nodes; And
Including a processor for controlling the transceiver,
The processor,
Replicating the sessions managed by the UPF node,
Determine whether an abnormal situation occurs while performing replication,
When an abnormal situation occurs, the replication of the sessions is paused for the first time.
UPF node. The method of claim 9,
The processor,
Based on at least one of a load state of the UPF node or the other UPF node, an interface state and a QoS state, and a replication rate of the sessions and a data traffic transmission/reception rate of a terminal corresponding to the replicated sessions, the To determine whether an abnormal situation has occurred
UPF node. The method of claim 9,
The processor,
After the first time has elapsed, it is determined again whether the abnormal situation has occurred, and
If the abnormal situation is not resolved, to determine the interruption and restoration (restoration) of the replication of the sessions
UPF node. The method of claim 11,
The processor,
By controlling the transceiver, requesting the SMF node for approval of the interruption of the replication and the execution of the original state restoration,
By controlling the transceiver, in response to the request, receiving approval for the interruption of the replication and the execution of the original state restoration
UPF node. The method of claim 11,
The processor,
According to the determination, by controlling the transceiver, and transmits an original restoration performance message to the other UPF node,
The original restoration performance message is used by the second UPF node to delete some of the previously transmitted sessions.
UPF node. The method of claim 9,
The processor,
The sessions are grouped into one session set and transmitted at a time.
UPF node. The method of claim 9,
The UPF includes a plurality of virtualized first UPF instances,
The other UPF includes a plurality of virtualized second UPF instances,
The processor,
Replicating sessions managed by any one of the plurality of first UPF instances to any one of the second UPF instances
UPF node. The method of claim 9,
The processor,
Determine the order of transmitting the sets based on the monitored information,
The monitoring information,
Including at least one of a processing speed and a resource state of the first UPF node and the second UPF node, a bandwidth between the first UPF and the second UPF 200b, and a transmission rate required for a session to be duplicated.
UPF node. As a computer-readable recording medium storing a computer program,
When the computer program is executed by a processor,
A computer-readable recording medium comprising instructions for causing a processor to perform the method according to any one of claims 1 to 8. As a computer program stored in a computer-readable recording medium,
When the computer program is executed by a processor,
A computer program comprising instructions for causing the processor to perform a method according to claim 1.

Images