Terminal service processing system, method and equipment

Abstract

The invention relates to a terminal service processing system, method and device, and belongs to the technical field of data processing.The system comprises a broadband access server resource pool and a router, and a plurality of broadband access server devices are arranged in the broadband access server resource pool. The first broadband access server equipment is used for determining first broadband access server equipment which has jurisdiction to a user terminal in a two-layer access network; the first broadband access server equipment is used for receiving service data sent by the user terminal and sending the service data to the router; the router is used for routing the service data to related services, receiving service return data returned by the related services, and routing the service return data to the broadband access server resource pool; the broadband access server resource pool is further used for determining a second broadband access server used for sending the service return data to the user terminal. According to the method, the pooling load function is realized without depending on the PPPOE dialing process, the applicability is wide, and the deployment is simple.

Description

Technical Field

[0001] The present invention relates to the field of data processing technology, and in particular to a terminal service processing system, method and device. Background Art

[0002] With the continuous development of network technology, the use scenarios of metropolitan area networks and campus networks are increasing, and users' requirements for network environment are also getting higher and higher. Broadband access server equipment is used to realize the access, authentication, billing and control functions of user terminals in metropolitan area networks and campus networks. It is the core key equipment in the network. Therefore, high requirements are put forward for the reliability, scalability and self-healing of broadband access server equipment.

[0003] In the prior art, the performance of broadband access server devices is improved by pooling the resources of the broadband access server devices. For example, PPPOE (Point-to-Point Protocol Over Ethernet, a point-to-point communication protocol based on Ethernet) technology is used to implement resource pooling of broadband access server devices. In this technical solution, when a user terminal has a demand for processing business data, the user terminal must use PPPOE dial-up when accessing the device, which is difficult to adapt to the needs of regular access scenarios of mobile terminals, and cannot effectively process terminal business data, thereby reducing user experience.

[0004] It can be seen that in the existing resource pooling technology of broadband access server equipment, the service data processing of the user terminal needs to be PPPOE dialed first, which cannot meet the needs of regular access scenarios of mobile terminals, and the terminal service data cannot be processed in a timely and effective manner. Summary of the invention

[0005] In view of this, it is necessary to provide a terminal service processing system, method and device to solve the problem that in the resource pooling technology of the existing broadband access server equipment, the service data processing of the user terminal requires PPPOE dial-up first, which cannot adapt to the needs of regular access scenarios of mobile terminals and the terminal service data cannot be processed in a timely and effective manner.

[0006] In order to solve the above problems, the present invention provides a terminal service processing system, comprising: a broadband access server resource pool and a router, wherein: The broadband access server resource pool is provided with a plurality of broadband access server devices, which are used to determine a first broadband access server device having jurisdiction over the user terminal in the layer 2 access network; the first broadband access server device is used to receive service data sent by the user terminal and send the service data to the router; The router is used to route the service data to the related service, receive the service return data returned by the related service, and route the service return data to the broadband access server resource pool; The broadband access server resource pool is further used to determine a second broadband access server for sending the service return data to the user terminal.

[0007] In a possible implementation manner, the user terminal is further used to broadcast an ARP query to the broadband access server resource pool; The broadband access server resource pool is further used to determine the first broadband access server device in the broadband access server resource pool that has jurisdiction over the user terminal based on a preset arbitration algorithm; The first broadband access server is used to respond to the ARP query and establish a session connection with the user terminal.

[0008] In a possible implementation, each broadband access server device in the broadband access server resource pool is used to establish an ARP takeover information table of the user terminal based on the ARP query, and the ARP takeover information table of the user terminal includes the MAC address, IP address, virtual local area network of the user terminal, virtual local area network of the broadband access server device, and MAC address of the broadband access server device.

[0009] In a possible implementation manner, when sending the service return data to the user terminal, the second broadband access server device is configured to: Determine the business return data that can be released based on the preset access control policy; Changing the source MAC address in the data returned by the service that can be released to the MAC address of the second broadband access server device, and changing the target MAC address in the data returned by the service that can be released to the MAC address of the user terminal; The released service return data after the MAC address is changed is sent to the user terminal.

[0010] In a possible implementation manner, the broadband access server resource pool is further used for: The operation information of each broadband access server device in the broadband access server resource pool is synchronized based on a preset frequency, wherein the operation information includes status information, network interface information and ARP takeover information table of user terminals governed by each broadband access server device.

[0011] In a possible implementation manner, when the first broadband access server device fails, the broadband access server resource pool is further used to: Determining, based on the status information and network interface information of each of the broadband access server devices, a third broadband access server device that can replace the first broadband access server device; The third broadband access server device is used to manage the user terminal based on the ARP takeover information table of the user terminal managed by the first broadband access server device.

[0012] In a possible implementation manner, the broadband access server resource pool is further used for: When it is determined based on the synchronized operation information of each of the broadband access server devices that the first broadband access server device has returned to normal, the first broadband access server device resumes the administration of the user terminal.

[0013] In a possible implementation manner, the broadband access servers in the broadband access server resource pool may be smoothly expanded or reduced.

[0014] The present invention further provides a terminal service processing method, which processes the terminal service based on the terminal service processing system described in any of the above embodiments, including: Determining a first broadband access server device having jurisdiction over a user terminal in a layer 2 access network in a preset broadband access server resource pool; Controlling the first broadband access server device to receive the service data sent by the user terminal, and sending the service data to the router; Control the router to route the service data to the related service, receive the service return data returned by the related service, and route the service return data to the second broadband access server device in the broadband access server resource pool, wherein the second broadband access server device is used to send the service return data to the user terminal.

[0015] The present invention also provides a terminal service processing device, comprising a computer-readable storage medium for storing a computer-readable program or instruction, wherein the program or instruction can implement the steps in the above-mentioned terminal service processing method when executed by a processor.

[0016] The beneficial effects of the present invention are as follows: the terminal service processing system provided by the present invention determines a first broadband access server device having jurisdiction over a user terminal in a layer 2 access network in a preset broadband access server resource pool, and the first broadband access server device can receive service data sent by the user terminal without PPPOE dialing, and send the service data to a router, the router routes the service data to related services, and receives service return data returned by the related services, and routes the service return data to a second broadband access server device in the broadband access server resource pool, the second broadband access server device sends the service return data to the user terminal, all broadband access server devices in the resource pool can provide service functions such as terminal access, network forwarding, and access control for the user terminal, and does not rely on the PPPOE dialing process to realize resource pooling, but only relies on the conventional Ethernet communication process to realize resource pooling of broadband access server devices, has wide applicability, is simple to deploy, can realize real service load balancing, improve resource utilization, and respond to terminal services more quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic diagram of the structure of a terminal service processing system provided by an embodiment of the present invention; Figure 2 A flowchart of a method for returning business data provided by an embodiment of the present invention; Figure 3 A schematic diagram of a flow chart of a device replacement method provided in an embodiment of the present invention; Figure 4 A schematic diagram of a process flow of a terminal service processing method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0020] The descriptions of "first", "second", etc. involved in the embodiments of the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the technical features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0021] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0022] A specific embodiment of the present invention, as Figure 1 As shown, a terminal service processing system is disclosed, which includes a broadband access server resource pool and a router, wherein: A plurality of broadband access server devices are arranged in the broadband access server resource pool, and are used to determine a first broadband access server device having jurisdiction over a user terminal in a layer 2 access network; the first broadband access server device is used to receive service data sent by the user terminal and send the service data to a router; The router is used to route the service data to the related services, receive the service return data returned by the related services, and route the service return data to the broadband access server resource pool; The broadband access server resource pool is also used to determine a second broadband access server for sending the service return data to the user terminal.

[0023] In an embodiment of the present invention, a preset BRAS (Broadband Remote Access Server) / VBRAS (virtualized Broadband Remote Access Server) resource pool includes multiple BRAS / VBRAS devices, which are expandable multiple BRAS or VBRAS devices with independent systems. For a network access area, there are multiple user terminals, and the multiple user terminals are in a two-layer access network environment. The two-layer access network refers to a two-layer network structure with only a core layer and an access layer. The switch forwards data packets according to the MAC address table. The BRAS / VBRAS resource pool is connected to a router, and data is exchanged with related services through the router.

[0024] In an embodiment of the present invention, for a user terminal in a Layer 2 access network environment, before the user terminal accesses the metropolitan area network or the campus network, it is necessary to first determine the BRAS / VBRAS device in the BRAS / VBRAS resource pool that has jurisdiction over the user terminal. Optionally, for each user terminal in the same access network, one BRAS / VBRAS device can simultaneously govern multiple user terminals, and each user terminal in the same access network can be governed by different BRAS / VBRAS devices. How to determine the BRAS / VBRAS device that has jurisdiction over the user terminal will be described later in the present invention.

[0025] In an embodiment of the present invention, after determining the first BRAS / VBRAS device that has jurisdiction over the user terminal, the first BRAS / VBRAS device can directionally receive service data sent by the user terminal, wherein the service data is sent in the form of a message, and the first BRAS / VBRAS device sends the service data message to the router through the default route. After receiving the service data, the router routes the service data to the relevant service based on the specific content of the service data, and the relevant service processes the service data and sends the service return data obtained after the processing to the router.

[0026] In the embodiment of the present invention, after receiving the service return data returned by the relevant service, the router returns the service return data to the second BRAS / VBRAS device, wherein the second BRAS / VBRAS device may be the same device as the first BRAS / VBRAS device, or may be a different device, and the second BRAS / VBRAS device may be specifically determined according to a preset static routing load sharing strategy or a dynamic routing load sharing strategy. After receiving the service return data, the second BRAS / VBRAS device sends the service return data to the user terminal to complete the processing of the service data.

[0027] The terminal service processing system provided by the present invention determines a first broadband access server device having jurisdiction over a user terminal in a layer 2 access network in a preset broadband access server resource pool. Without PPPOE dialing, the first broadband access server device can receive service data sent by the user terminal and send the service data to a router. The router routes the service data to related services and receives service return data returned by the related services, and routes the service return data to a second broadband access server device in the broadband access server resource pool. The second broadband access server device sends the service return data to the user terminal. All broadband access server devices in the resource pool can provide service functions such as terminal access, network forwarding, and access control for the user terminal. Resource pooling is achieved without relying on a PPPOE dialing process, and resource pooling of broadband access server devices can be achieved only by relying on a conventional Ethernet communication process. The system has wide applicability and simple deployment, can achieve real service load balancing, improve resource utilization, and respond to terminal services more quickly.

[0028] As a possible implementation mode of the present invention, in this implementation mode, the user terminal is further used to broadcast an ARP query to the broadband access server resource pool; The broadband access server resource pool is also used to determine the first broadband access server device in the broadband access server resource pool that has jurisdiction over the user terminal based on a preset arbitration algorithm; The first broadband access server is used for responding to the ARP query and establishing a session connection with the user terminal.

[0029] In an embodiment of the present invention, before a user terminal accesses a metropolitan area network or a campus network, it needs to first perform an ARP (Address Resolution Protocol) query to query the MAC (Media Access Control Address) address of its own gateway. Because the user terminal has no corresponding BRAS / VBRAS device before accessing the network, the user terminal directly broadcasts the ARP query to the BRAS / VBRAS device resource pool. After receiving the ARP query, each BRAS / VBRAS device in the BRAS / VBRAS device resource pool determines the BRAS / VBRAS device that has jurisdiction over the user terminal based on a preset arbitration algorithm. The preset arbitration algorithm may be a static algorithm or a dynamic algorithm, such as allocating user terminals to the BRAS / VBRAS devices in sequence based on the order of the BRAS / VBRAS devices in the BRAS / VBRAS device resource pool, or evenly allocating based on the number of user terminals governed by each BRAS / VBRAS device in the BRAS / VBRAS device resource pool, or allocating based on the performance of each BRAS / VBRAS device in the BRAS / VBRAS device resource pool. The present invention does not limit this.

[0030] Furthermore, after determining the first BRAS / VBRAS device that has jurisdiction over the user terminal, the first BRAS / VBRAS device responds to the ARP query, establishes a session connection between the first BRAS / VBRAS device and the user terminal, and sends the gateway MAC address of the user terminal to the user terminal through the session.

[0031] In the embodiment of the present invention, the user terminal performs an ARP query in the form of broadcasting. After receiving the ARP query, each BRAS / VBRAS device in the BRAS / VBRAS device resource pool determines the first BRAS / VBRAS device that has jurisdiction over the user terminal based on a preset arbitration algorithm. The user terminal can access the network without PPPOE dial-up, which is convenient and fast and can be applied to the network access needs of mobile terminals.

[0032] As a possible implementation mode of the present invention, in this implementation mode, each broadband access server device in the broadband access server resource pool is used to establish an ARP takeover information table of the user terminal based on the ARP query, and the ARP takeover information table of the user terminal includes the MAC address, IP address, virtual LAN of the user terminal, virtual LAN of the broadband access server device, and the MAC address of the broadband access server device.

[0033] In the embodiment of the present invention, after the user terminal broadcasts the ARP query, in order to prevent the BRAS / VBRAS device that has jurisdiction over the user terminal from failing in the future and causing the user terminal to be unable to access the network, the BRAS / VBRAS device that receives the ARP query will establish its own ARP takeover information table about the user terminal based on the ARP query. The ARP takeover information table includes the MAC address, IP address, virtual LAN of the user terminal, the virtual LAN of the broadband access server device itself, and the MAC address of the broadband access server device itself, that is, all BRAS / VBRAS devices in the BRAS / VBRAS device resource pool have a backup of the ARP takeover information table of the user terminal. When the first BRAS / VBRAS device fails, it can be seamlessly connected to other BRAS / VBRAS devices, so as to realize automatic takeover of the BRAS / VBRAS device and ensure the stability of the user terminal network.

[0034] Optional, such as Figure 2 As shown, when the second broadband access server device sends the service return data to the user terminal, it is used to: S201, determining the releaseable service return data based on the preset access control policy; S202, changing the source MAC address in the data returned by the service that can be released to the MAC address of the second broadband access server device, and changing the target MAC address in the data returned by the service that can be released to the MAC address of the user terminal; S203, sending the released service return data after the MAC address is changed to the user terminal.

[0035] In an embodiment of the present invention, before sending the service return data to the user terminal, the second BRAS / VBRAS device needs to filter the service return data. Specifically, the second BRAS / VBRAS device determines the releasable service return data in the service return data based on a preset access control policy. For example, for some user terminals, they are only allowed to access. When there is a data download service in the service return data, the data download service is filtered and only the data access service is released to prevent the user terminal from performing over-authorized service exchanges. After determining the releasable service return data, based on the target IP address in the releasable service return data, the ARP takeover information table of the user terminal is queried, and the access side MAC address of the corresponding access gateway and the MAC address of the user terminal are determined, and then the source MAC address in the releasable service return data message is changed to the access side MAC address of the BRAS / VBRAS device corresponding to the user terminal, and the target MAC address is changed to the MAC address of the user terminal, and the releasable service data is sent to the user terminal.

[0036] When sending service return data to a user terminal, the embodiment of the present invention filters the service return data through a preset access control policy to obtain the releasable service return data, thereby ensuring that the user terminal does not have excessive access authority. At the same time, by modifying the MAC address in the releasable service return data, it is ensured that the releasable service return data can be sent to the user terminal.

[0037] As a possible implementation manner of the present invention, in this implementation manner, the broadband access server resource pool is further used for: Based on a preset frequency, the operation information of each broadband access server device in the broadband access server resource pool is synchronized, and the operation information includes the status information of each broadband access server device, the network interface information and the ARP takeover information table of the user terminal managed by each broadband access server device.

[0038] In an embodiment of the present invention, in order to ensure the stability of user terminal access to the network, for each BRAS / VBRAS device in the BRAS / VBRAS device resource pool, the operation information of each BRAS / VBRAS device is synchronized through a heartbeat strategy and a dedicated data synchronization link, wherein the operation information includes but is not limited to the operation status information of each BRAS / VBRAS device, the status information of each network interface, and the ARP takeover information table of the user terminal corresponding to each BRAS / VBRAS device.

[0039] Further, such as Figure 3 As shown, when the first broadband access server device fails, the broadband access server resource pool is also used to: S301, determining a third broadband access server device that can replace the first broadband access server device based on status information and network interface information of each broadband access server device; S302: The third broadband access server device is used to manage the user terminal based on the ARP takeover information table of the user terminal managed by the first broadband access server device.

[0040] In an embodiment of the present invention, when any BRAS / VBRAS device in a BRAS / VBRAS device resource pool fails, other devices in the BRAS / VBRAS device resource pool can take over the user terminal under the jurisdiction of the BRAS / VBRAS device to ensure the stability of the network connection of the user terminal. For example, when a first BRAS / VBRAS device fails, the heartbeat strategy is used to find that the first BRAS / VBRAS device fails. The other BRAS / VBRAS devices in the BRAS / VBRAS device resource pool determine, based on a preset arbitration algorithm, a third BRAS / VBRAS device for taking over the user terminal under the jurisdiction of the first BRAS / VBRAS device. The third BRAS / VBRAS device forwards the service data and service return data of the user terminal to ensure the normal operation of the user terminal service.

[0041] In the embodiment of the present invention, when a certain BRAS / VBRAS device fails, other BRAS / VBRAS devices in the BRAS / VBRAS device resource pool can automatically take over the work of the BRAS / VBRAS device, thereby ensuring the stability of the network connection of the user terminal.

[0042] Furthermore, the broadband access server resource pool is also used for: When it is determined based on the synchronized operation information of each broadband access server device that the first broadband access server device has returned to normal, the first broadband access server device resumes the administration of the user terminal.

[0043] In the embodiment of the present invention, when the first BRAS / VBRAS device that has failed returns to normal, the next time the user terminal transmits service data, the service data is automatically restored to the first BRAS / VBRAS device, and other BRAS / VBRAS devices no longer respond to the user terminal.

[0044] Optionally, the broadband access servers in the broadband access server resource pool may be smoothly expanded or reduced.

[0045] In the embodiment of the present invention, the broadband access server devices in the broadband access server resource pool are independent of each other and have independent systems. The broadband access server devices in the broadband access server can be expanded or reduced to meet user needs.

[0046] Furthermore, the embodiment of the present invention also provides a terminal service processing method, such as Figure 4 As shown, the method for processing the terminal service based on the terminal service processing system in any of the aforementioned embodiments includes: S401, determining a first broadband access server device having jurisdiction over a user terminal in a layer 2 access network in a preset broadband access server resource pool; S402, controlling the first broadband access server device to receive service data sent by the user terminal, and sending the service data to the router; S403, control the router to route the service data to the related service, receive the service return data returned by the related service, and route the service return data to the second broadband access server device in the broadband access server resource pool, and the second broadband access server device is used to send the service return data to the user terminal.

[0047] The terminal service processing method provided by the present invention determines a first broadband access server device having jurisdiction over a user terminal in a layer 2 access network in a preset broadband access server resource pool, and can receive service data sent by the user terminal without PPPOE dialing, and send the service data to a router, and the router routes the service data to related services, and receives service return data returned by the related services, and routes the service return data to a second broadband access server device in the broadband access server resource pool, and the second broadband access server device sends the service return data to the user terminal, and all broadband access server devices in the resource pool can provide terminal access, network forwarding, access control and other service functions for the user terminal, and resource pooling can be realized by relying on a conventional Ethernet communication process instead of a PPPOE dialing process, and the resource pooling of broadband access server devices can be realized by relying on a wide range of applicability and simple deployment, and can realize real service load balancing, improve resource utilization, and respond to terminal services more quickly.

[0048] Correspondingly, an embodiment of the present invention also provides a terminal service processing device, including a computer-readable storage medium for storing computer-readable programs or instructions. When the program or instructions are executed by a processor, the steps or functions in the terminal service processing method provided in the above-mentioned method embodiments can be implemented.

[0049] Those skilled in the art can understand that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0050] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A terminal service processing system, characterized in that: include: Broadband access server resource pool and router, where: The broadband access server resource pool is provided with a plurality of broadband access server devices, which are used to determine a first broadband access server device having jurisdiction over the user terminal in the layer 2 access network; the first broadband access server device is used to receive service data sent by the user terminal and send the service data to the router; The router is used to route the service data to the related service, receive the service return data returned by the related service, and route the service return data to the broadband access server resource pool; The broadband access server resource pool is further used to determine a second broadband access server for sending the service return data to the user terminal.

2. The terminal service processing system according to claim 1, characterized in that: The user terminal is also used to broadcast an ARP query to the broadband access server resource pool; The broadband access server resource pool is further used to determine the first broadband access server device in the broadband access server resource pool that has jurisdiction over the user terminal based on a preset arbitration algorithm; The first broadband access server is used to respond to the ARP query and establish a session connection with the user terminal.

3. The terminal service processing system according to claim 2, characterized in that: Each broadband access server device in the broadband access server resource pool is used to establish an ARP takeover information table of the user terminal based on the ARP query, and the ARP takeover information table of the user terminal includes the MAC address, IP address, virtual local area network of the user terminal, virtual local area network of the broadband access server device and the MAC address of the broadband access server device.

4. The terminal service processing system according to claim 3, characterized in that: When sending the service return data to the user terminal, the second broadband access server device is used to: Determine the business return data that can be released based on the preset access control policy; Changing the source MAC address in the data returned by the service that can be released to the MAC address of the second broadband access server device, and changing the target MAC address in the data returned by the service that can be released to the MAC address of the user terminal; The released service return data after the MAC address is changed is sent to the user terminal.

5. The terminal service processing system according to claim 3, characterized in that: The broadband access server resource pool is also used for: The operation information of each broadband access server device in the broadband access server resource pool is synchronized based on a preset frequency, wherein the operation information includes status information, network interface information and ARP takeover information table of user terminals governed by each broadband access server device.

6. The terminal service processing system according to claim 5, characterized in that: When the first broadband access server device fails, the broadband access server resource pool is further used to: Determining, based on the status information and network interface information of each of the broadband access server devices, a third broadband access server device that can replace the first broadband access server device; The third broadband access server device is used to manage the user terminal based on the ARP takeover information table of the user terminal managed by the first broadband access server device.

7. The terminal service processing system according to claim 6, characterized in that: The broadband access server resource pool is also used for: When it is determined based on the synchronized operation information of each of the broadband access server devices that the first broadband access server device has returned to normal, the first broadband access server device resumes the administration of the user terminal.

8. The terminal service processing system according to claim 1, characterized in that: The broadband access servers in the broadband access server resource pool can be smoothly expanded or reduced.

9. A terminal service processing method, characterized in that: The terminal service processing system according to any one of claims 1 to 7 processes the terminal service, including: Determining a first broadband access server device having jurisdiction over a user terminal in a layer 2 access network in a preset broadband access server resource pool; Controlling the first broadband access server device to receive the service data sent by the user terminal, and sending the service data to the router; Control the router to route the service data to the related service, receive the service return data returned by the related service, and route the service return data to the second broadband access server device in the broadband access server resource pool, wherein the second broadband access server device is used to send the service return data to the user terminal.

10. A terminal service processing device, comprising a storage medium for storing a computer-readable program or instruction, wherein the program or instruction, when executed by a processor, can implement the steps of the terminal service processing method according to claim 9.

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