KR102440108B1 - Method and system for determining shortest edge server - Google Patents

Abstract

The present invention relates to a method for determining a shortest edge server for one of a plurality of clients in a CDN including an original server, a plurality of edge servers, and the clients. The method of the present invention comprises the steps of: requesting a list of a plurality of edge servers to an original server; transmitting first data including a first TTL value to each of the edge servers on the basis of the list of the edge servers; receiving second data including a second TTL value associated with the first TTL value from each of the edge servers; and determining a shortest edge server of one client on the basis of the difference between the first and second TTL values. Therefore, more efficient traffic processing (distribution) can be performed.

Description

METHOD AND SYSTEM FOR DETERMINING SHORTEST EDGE SERVER

The present invention relates to a method and system for determining the shortest edge server for a plurality of clients in a content delivery network (CDN).

When a content provider provides content on the Internet in response to a content provision request from a client, in general, the number of clients as well as the number of requests is large or continuous in most cases. In addition, with the development of communication technology, the capacity of the content requested by the client has increased, and accordingly, a higher transmission quality is required for content transmission.

A CDN (Content Delivery Network) is a network of geographically distributed edge servers. In a CDN, in response to a client's request for content provision, geographically distributed edge servers are configured to provide content, rather than an origin server that holds the original content of the content. Accordingly, the edge servers process traffic to the origin server without requesting the origin server, thereby solving the problem of traffic spikes to the origin server and achieving higher transmission quality as a result of traffic distribution.

In the conventional CDN, a client provides content from a geographically nearby edge server, and the geographically nearby edge server is determined using a Border Gateway Protocol (BGP). BGP is a routing protocol that determines an edge server that is geographically close to a client by exchanging routing and reachability information between Autonomous Systems (AS) on the Internet by a router.

Accordingly, in order to build a conventional CDN using BGP, it is necessary to replace or reconfigure the entire network equipment such as a router (eg, reconfigure routing protocols, reassign routing tables, etc.). After all, in order to build a conventional CDN, it is essential to build or change a network infrastructure regardless of a client.

Construction or change of a network infrastructure for building a conventional CDN is time-consuming or costly due to a long downtime due to replacement, reconfiguration, or reconfiguration of large-scale network equipment. In addition, when a network infrastructure such as an intranet is designed without considering the construction of the conventional CDN, it is actually very difficult to build or change the network infrastructure for building the conventional CDN.

The inventors of the present invention have recognized the above problems with respect to the construction or change of the network infrastructure.

Accordingly, an object to be solved in the present invention is to provide a method and system capable of receiving content by finding the logically closest and logically closest edge server at the application level without building or changing a network infrastructure.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In a CDN including an origin server, a plurality of edge servers, and a plurality of clients according to an embodiment of the present invention in order to solve the above problems, determining the shortest edge server for one of the plurality of clients A method is provided. The method includes sending a request for a list of a plurality of edge servers to an origin server; transmitting, based on the list of the plurality of edge servers, first data including a first TTL value to each of the plurality of edge servers; receiving second data including a second TTL value associated with the first TTL value from each of the plurality of edge servers; and determining, based on the difference between the first TTL value and the second TTL value, the shortest edge server of the one client.

According to a feature of the present invention, the difference between the first TTL value and the second TTL value may be a logical distance value indicating the number of routers between one client and each of the plurality of edge servers.

According to another feature of the present invention, the step of determining the shortest edge server of one client may be performed without using a routing protocol of routers.

According to another aspect of the present invention, the determining of the shortest edge server of one client may include determining an edge server having the smallest difference between the first TTL value and the second TTL value as the shortest edge server.

According to another feature of the present invention, when the number of edge servers having the smallest difference between the first TTL value and the second TTL value is two or more, the step of determining the shortest edge server of one client includes: another client among the plurality of clients requesting data for the shortest edge server of ; and determining the shortest edge server of the specific client based on the data on the shortest edge server of the other client.

According to another feature of the present invention, the shortest edge server of the other client may be an edge server that was last connected to the other client or an edge server connected to the other client when requesting data for the shortest edge server of the other client.

According to another feature of the present invention, the origin server may be a head office server connected to two or more branch offices, the plurality of clients may be clients in at least two or more intranets, and the two or more intranets may correspond to each of the two or more branch offices.

In order to solve the above problems, a client for determining the shortest edge server according to another embodiment of the present invention is provided. The client includes: a communication unit configured to communicate with a plurality of edge servers; a storage configured to store a list of the plurality of edge servers; and a control unit operatively connected to the communication unit and the storage unit, wherein the control unit is configured to send a request for a list of the plurality of edge servers to an origin server, based on the list of the plurality of edge servers, configured to transmit, via the communication unit, first data including a first TTL value to each of the plurality of edge servers, and including a second TTL value associated with the first TTL value from each of the plurality of edge servers and receive second data, and determine, based on a difference between the first TTL value and the second TTL value, a shortest edge server of the one client.

The details of other embodiments are included in the detailed description and drawings.

The present invention can determine the shortest edge server by the client without building or changing the network infrastructure.

Furthermore, according to the present invention, more efficient traffic processing (distribution) is possible under a given CDN resource without building or changing network infrastructure.

In addition, the present invention can determine the shortest edge server by the client in an intranet environment where it is difficult to build or change the network infrastructure.

The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present invention.

1 is a schematic diagram of a system for determining the shortest edge server according to an embodiment of the present invention;
2 is a block diagram showing the configuration of a client according to an embodiment of the present invention.
3 is a flowchart schematically illustrating a method for determining a shortest edge server according to an embodiment of the present invention.
4 is a schematic diagram illustrating transmission and reception of data including a TTL value in communication between a client and an edge server in a method for determining a shortest edge server according to an embodiment of the present invention.
5 is a schematic diagram illustrating a method for determining a shortest edge server according to another embodiment of the present invention.
6 is a schematic diagram illustrating a method for determining a shortest edge server in an intranet environment according to another embodiment of the present invention.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be embodied in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. In connection with the description of the drawings, like reference numerals may be used for like components.

In this document, expressions such as "has," "may have," "includes," or "may include" refer to the presence of a corresponding characteristic (eg, a numerical value, function, operation, or component such as a part). and does not exclude the presence of additional features.

In this document, expressions such as "A or B," "at least one of A or/and B," or "one or more of A or/and B" may include all possible combinations of the items listed together. . For example, "A or B," "at least one of A and B," or "at least one of A or B" means (1) includes at least one A, (2) includes at least one B; Or (3) it may refer to all cases including both at least one A and at least one B.

As used herein, expressions such as "first," "second," "first," or "second," may modify various elements, regardless of order and/or importance, and refer to one element. It is used only to distinguish it from other components, and does not limit the components. For example, the first user equipment and the second user equipment may represent different user equipment regardless of order or importance. For example, without departing from the scope of the rights described in this document, the first component may be named as the second component, and similarly, the second component may also be renamed as the first component.

A component (eg, a first component) is "coupled with/to (operatively or communicatively)" to another component (eg, a second component) When referring to "connected to", it should be understood that the certain element may be directly connected to the other element or may be connected through another element (eg, a third element). On the other hand, when it is said that a component (eg, a first component) is "directly connected" or "directly connected" to another component (eg, a second component), the component and the It may be understood that other components (eg, a third component) do not exist between other components.

As used herein, the expression "configured to (or configured to)" depends on the context, for example, "suitable for," "having the capacity to ," "designed to," "adapted to," "made to," or "capable of." The term “configured (or configured to)” may not necessarily mean only “specifically designed to” hardware. Instead, in some circumstances, the expression “a device configured to” may mean that the device is “capable of” with other devices or parts. For example, the phrase "a processor configured (or configured to perform) A, B, and C" refers to a dedicated processor (eg, an embedded processor) for performing the operations, or by executing one or more software programs stored in a memory device. , may mean a generic-purpose processor (eg, a CPU or an application processor) capable of performing corresponding operations.

Terms used in this document are only used to describe specific embodiments, and may not be intended to limit the scope of other embodiments. The singular expression may include the plural expression unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meanings as commonly understood by one of ordinary skill in the art described in this document. Among the terms used in this document, terms defined in a general dictionary may be interpreted with the same or similar meaning to the meaning in the context of the related art, and unless explicitly defined in this document, ideal or excessively formal meanings is not interpreted as In some cases, even terms defined in this document cannot be construed to exclude embodiments of the present document.

Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, and as those skilled in the art will fully understand, technically various interlocking and driving are possible, and each embodiment may be independently implemented with respect to each other. It may be possible to implement together in a related relationship.

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

1 is a schematic diagram of a system for determining the shortest edge server in a CDN according to an embodiment of the present invention;

Referring to FIG. 1 , the system for determining the shortest edge server in the CDN includes an origin server 100 , a client 200 , and an edge server 300 .

The origin server 100 is a server configured to hold the original content of the CDN. In the present invention, the content (contents) is not limited and includes data such as images, videos, music, documents, and web pages that can be downloaded through a server on the Internet. The edge server 300 is a server configured to store and/or cache some or all of the content provided from the original server 100 . The edge server 300 is also referred to as a CDN server, a replication server, a caching server, or the like. The client 200 is not limited and refers to a user device requesting the provision of content. The client 200 may include, for example, a general purpose computer, a laptop, a server, a network-attached storage, a tablet device, a smartphone, and the like.

The client 200 makes a request for content from the origin server 100 , but receives the content from the edge server 300 instead of directly receiving the content from the origin server 100 . The edge server 300 is generally a server that is geographically more closely distributed as compared to the client 200 and the origin server 100 . Accordingly, the client 200 may receive the corresponding content with a higher transmission quality than receiving the corresponding content directly from the edge server 100 , and traffic concentrated on the original server 100 may be distributed.

2 is a block diagram showing the configuration of a client according to an embodiment of the present invention.

Referring to FIG. 2 , the client 200 includes a communication unit 210 , a control unit 220 , and a storage unit 230 .

The communication unit 210 may transmit a request for a list of edge servers 300 to the original server 100 , and may transmit/receive data for checking a difference in TTL values to the edge server 300 . The communication unit 210 may receive content from the edge server 300 . The communication unit 210 may request the original server 100 for data on the shortest edge server of the other client from the other client, and may receive such data. In addition, the communication unit 210 may receive (obtain) such data from another server or device (eg, a specific edge server) that has received data for the shortest edge server of another client from the original server 100 . The communication unit 210 is not limited, and a wireless communication unit (eg, a cellular communication unit, a short-range wireless communication unit, etc.) or a wired communication unit (eg, a local area network (LAN) communication unit, a power line communication unit, a data transmission line communication unit, etc.) and may communicate with the original server 100 or the edge server 300 using a corresponding communication unit among them.

The storage unit 230 may store content or data received through the communication unit 210 , and may store a list of edge servers received from the original server 100 , data on the shortest edge server of another client, and the like.

The control unit 220 is operatively connected to the communication unit 210 and the storage unit 230 . The controller 220 may control or perform an operation related to the method for determining an enemy edge server according to the present invention. The controller 220 is not limited and may include a dedicated processor (eg, an embedded processor), a generic-purpose processor (eg, a CPU or an application processor). Hereinafter, the operation of the control unit 220 will be briefly described.

In various embodiments, the controller 220 may transmit a request for a list of a plurality of edge servers to the original server through the communication unit 210 . The controller 220 may transmit the first data including the first TTL value to each of the plurality of edge servers based on the list of the plurality of edge servers through the communication unit 210 . The controller 220 may receive the second data including the second TTL value associated with the first TTL value from each of the plurality of edge servers through the communication unit 210 . The controller 220 may determine the shortest edge server of one client based on a difference between the first TTL value and the second TTL value. The controller 220 may determine an edge server having the smallest difference between the first TTL value and the second TTL value as the shortest edge server. When the number of edge servers having the smallest difference between the first TTL value and the second TTL value is two or more, the control unit 220 determines a shortest edge server for one client, through the communication unit 210, a plurality of clients It is possible to request data on the shortest edge server of another client, and determine the shortest edge server of the specific client based on the data on the shortest edge server of the other client.

3 is a flowchart schematically illustrating a method for determining a shortest edge server according to an embodiment of the present invention.

Referring to FIG. 3 , a method for determining a shortest edge server according to an embodiment of the present invention includes: transmitting a request for a list of a plurality of edge servers to an origin server ( S300 ); transmitting first data including a first TTL value to each of the plurality of edge servers based on the list of edge servers (S310); Receiving second data including a second TTL value associated with the first TTL value from each of the plurality of edge servers (S320); and determining a shortest edge server of one client based on a difference between the first TTL value and the second TTL value ( S330 ).

First, one client 200 among the plurality of clients requests a list of the plurality of edge servers 300 from the original server 100 ( S300 ), and based on the list of the edge servers 300 , one client In step 200, the first data including the first TTL value is transmitted to each of the plurality of edge servers (S310).

Next, one client 200 among the plurality of clients receives second data including the second TTL value from each of the plurality of edge servers 300 ( S320 ). In this case, the second TTL value is a value associated with the first TTL value, and corresponds to a value obtained by subtracting the number of routers passed between each of the plurality of edge servers 300 from one client 200 from the first TTL value. .

Time To Live (TTL) is a value for how long a packet or data must exist in the network before being discarded from the router. Each time a packet or data passes through a router, the router decrements the TTL value by 1. In each path, a router configures hops, and whenever a packet or data passes through a router, which is an intermediate device, latency occurs. As the number of hops or the subtracted TTL value increases, data communication performance is degraded,

Receiving the data (first data and second data) including the TTL value in steps S310 and S320 allows the user to check how many routers the packet or data has passed through the edge server from the edge server using the TTL value. Because. Since the router is located geographically distributed between a local area network (LAN) and a wide area network (WAN), it is highly correlated with the actual distance. Accordingly, by checking the number of routers passed through, the client and the edge server can check the actual distance.

4 is a schematic diagram illustrating transmission and reception of data including a TTL value in communication between a client and an edge server in a method for determining a shortest edge server according to an embodiment of the present invention.

Referring to FIG. 4 , the client 200 transmits first data having TTL=64 to the edge server 300 . Since the first data goes through the two routers, the TTL value is subtracted by two. Accordingly, the edge server 300 receives the first data having TTL=64. The edge server 300 sends second data including a second TTL value associated with the first TTL value to the client 200 .

Next, the one client 200 among the plurality of clients determines the shortest edge server of the one client based on the difference between the first TTL value and the second TTL value ( S330 ).

Referring back to FIG. 4 , a second TTL indicating a TTL value of 64 of the first data transmitted by the client 200 and a TTL value of the first data received from the edge server 300 (via two routers) The difference of the value 62 becomes 2. The client 200 checks the difference between the first TTL value and the second TTL value as a logical distance value between the client 200 and the edge server 300 . The client 200 compares logical distance values identified from all edge servers 300 included in the list of edge servers, and determines the edge server having the smallest value as the shortest edge server.

In various embodiments, when the number of edge servers having the smallest difference between the first TTL value and the second TTL value is two or more, determining the shortest edge server of the client may include a shortest edge server of another client among the plurality of clients. obtaining data for and determining, based on the data on the shortest edge server of the other client, the shortest edge server of the particular client. Data for other clients may be received (obtained) from the origin server or from another server or device that has received such data from the origin server (eg, a particular edge server). In particular, when an intranet including a plurality of clients is built, one client and the other client can be connected on the intranet of the same company, government agency, etc. It can be readily obtained from other servers or devices that have received such data from For one client, there may be two edge servers having the smallest difference between the first TTL value and the second TTL value, for example, the first edge server and the second edge server. If it is confirmed that the first edge server corresponds to the shortest edge server of the other client, the one client may determine the second edge server instead of the first edge server as the shortest edge server of the one client. When the second edge server is determined as the shortest edge server than when the first edge server is determined as the shortest edge server of one client, traffic is more likely to be distributed. Accordingly, more efficient traffic processing is achieved under a given CDN resource or network infrastructure or without building or changing the network infrastructure.

In the present invention, since the client 200 determines the shortest edge server by comparing the logical distance values identified from the edge servers 300, the present invention is different from the CDN of the conventional method in which the shortest edge server is determined by the routing protocol. there is

Specifically, a router is a network device that connects independently configured networks, and the router generates a routing table by collecting and/or exchanging route information in an entire network in which the routers are interconnected. The process by which a router selects a route to a destination between a network or a plurality of networks by referring to a router table is called routing. The route to the destination may be automatically configured by a routing protocol (dynamic routing) or manually configured by an administrator (static routing).

In the conventional CDN, a route to a destination, that is, a route from a client to an edge server, is generally determined using a routing protocol called BGP. Accordingly, as described above, in order to build a CDN of the conventional method, it is essential to build or change a network infrastructure regardless of a client. In particular, when adding a router, you must manually designate the nearest (edge) server to the router in the routing table.

On the other hand, in the present invention, the client 200, not the router, can determine the shortest edge server without replacing or reconfiguring the entire network equipment such as a router. In particular, more efficient and automatic traffic processing is achieved by considering other clients when determining the shortest edge server. In particular, in the present invention, unlike the conventional CDN, the shortest edge server can be determined without using a routing protocol.

5 is a schematic diagram illustrating a method for determining a shortest edge server according to another embodiment of the present invention.

Referring to FIG. 5 , the CDN includes an origin server 100 , a plurality of edge servers 300-1 and 300-2, and a plurality of clients 200-1, 200-2 and 200-3. .

Hereinafter, a method of determining the shortest edge server based on one client 200 - 2 will be described with reference to FIG. 5 .

One client 200 - 2 transmits a request for a list of a plurality of edge servers to the original server 100 . One client 200 - 2 receives a plurality of edge servers 300 - 1 and 300 - 2 based on a list of the plurality of edge servers 300 - 1 and 300 - 2 received from the original server 100 . First data including the first TTL value for which TTL=64 is transmitted to all. Referring to FIG. 5 , since the first data is received at the edge server 300-1 through two routers 400-3 and 400-1 from one client 200-2, the edge server 300- The TTL value of the first data received in 1) is subtracted by 2 to become 62. That is, the second TTL value of the second data related to the first data received from the edge server 300 - 1 becomes 62, and the difference between the first TTL value and the second TTL value becomes 2. In addition, since the first data is received at the edge server 300-2 through three routers 400-3, 400-4, and 400-5 from one client 200-2, the edge server 300- The TTL value of the first data received in 2) is subtracted by 3 to become 61. That is, the second TTL value of the second data related to the first data received from the edge server 300 - 2 becomes 61, and the difference between the first TTL value and the second TTL value becomes 3. The edge server 300 - 1 having the smallest difference between the first TTL value and the second TTL value is determined as the shortest edge server. This determination process is not performed using the routing protocols of the routers 400-1, 400-3, 400-4, and 400-5, but is performed by one client 200-2.

Meanwhile, in the case of the other client 200-3 among the plurality of clients, the first data passes through the two routers 400-4 and 400-1 from the other client 200-3 to the edge server 300-1 ), and also the first data is received from the edge server 300-2 through the two routers 400-4 and 400-5 from the other client 200-3. Accordingly, in the case of the other client 200-3, for both the edge server 300-1 and the edge server 300-2, the difference between the first TTL value and the second TTL value is equal to 2, There are two edge servers in which the difference between the first TTL value and the second TTL value is 2, which is the smallest. In this case, as described above, the determination of the shortest edge server of the other client 200 - 3 may be determined based on the shortest edge server of the one client 200 - 1 . In FIG. 5 , since the shortest edge server of one client 200 - 1 is the edge server 300 - 1 , the client 200 - 3 increases the probability that the traffic is more distributed and for more efficient traffic processing, the edge server The edge server 300-2, not the server 300-1, determines the shortest edge server.

6 is a schematic diagram illustrating a method for determining a shortest edge server in an intranet environment according to another embodiment of the present invention. In the present invention, the intranet environment means an environment in which a plurality of clients are in the intranet.

Referring to FIG. 6 , the CDN includes an origin server 100 , a plurality of edge servers 300-3 and 300-4, and a plurality of clients 200-4, 200-5, 200-6, and 200-7. , 200-8, 200-9).

In various embodiments, the source server 100 corresponds to the headquarters 500 of a company, and the clients 200-4, 200-5, 200-6, and 200-7 are the first branch offices 600 of the company. ), and clients 200 - 8 and 200 - 9 are clients in the intranet of a second branch 700 of an enterprise. The intranet of the first branch 600 and the intranet of the second branch 700 are configured independently. In the first branch 600, for example, a router 400-8 and clients 200-6 and 200-7 directly connected to the router 400-8 are disposed on the first floor, and on the second floor The router 400-7 and clients 200-4 and 200-5 directly connected to the router 400-7 are disposed. In the second branch 700 , the router 400 - 10 and clients 200 - 8 and 200 - 9 directly connected to the router 400 - 10 are arranged.

The plurality of clients 200-4, 200-5, 200-6, 200-7, 200-8, 200-9 are clients in different branch offices (intranets) and are directly connected to different routers, It requests specific data from the head office 500 . Accordingly, even in a corporate intranet environment, a CDN may be requested to distribute traffic to the headquarters 500 .

In order to build a conventional CDN in an intranet environment, it is essential to build or change a network infrastructure. This is because most intranet environments are designed without considering the establishment of a conventional CDN. However, it is very difficult to construct or change the network infrastructure for establishing the conventional CDN because it takes a lot of time and money due to long downtime due to the replacement or reconfiguration or reconfiguration of large-scale network equipment.

In the present invention, the client can determine the shortest edge server without building or changing the network infrastructure. Referring back to FIG. 6, a plurality of clients 200-4, 200-5, 200-6, 200-7, 200-8, 200-9) each may determine a shortest edge server based on a difference between the first TTL value and the second TTL value.

Accordingly, in the Infranet environment, without the establishment or change of the network infrastructure for establishing the conventional CDN in the intranet environment, furthermore, the edge server closest to the router to which each of the plurality of clients is connected according to each branch or the number of floors of each branch Without specifying , a plurality of clients can automatically determine the shortest edge server by using a logical distance value (difference in TTL value) that is highly related to the actual distance.

Although one embodiment of the present invention has been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit of the present invention. have. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100: origin server
200: client
210: communication unit
220: control unit
230: storage
300: edge server
400: router
500: Headquarters
600: first branch
700: 2nd branch

Claims (8)

A method for determining a shortest edge server for one of the plurality of clients in a content delivery network (CDN) including an origin server, a plurality of edge servers, and a plurality of clients, the method comprising:
sending a request for a list of a plurality of edge servers to an origin server;
transmitting first data including a first TTL value to each of the plurality of edge servers based on the list of the plurality of edge servers;
receiving second data including a second TTL value associated with the first TTL value from each of the plurality of edge servers;
determining a shortest edge server of the one client based on a difference between the first TTL value and the second TTL value;
The determining of the shortest edge server of the one client includes determining an edge server having the smallest difference between the first TTL value and the second TTL value as the shortest edge server,
When the number of edge servers having the smallest difference between the first TTL value and the second TTL value is two or more, determining the shortest edge server of the one client includes:
acquiring data on a shortest edge server of another client among the plurality of clients; and
determining the shortest edge server of the one client based on data for the shortest edge server of the other client, and
The method of claim 1, wherein the shortest edge server of the other client is an edge server that was last connected to the other client or an edge server connected to the other client when requesting data about the shortest edge server of the other client. The method of claim 1,
The difference between the first TTL value and the second TTL value is a logical distance value indicating the number of routers between the one client and each of the plurality of edge servers. 3. The method of claim 2,
and determining the shortest edge server of the one client is performed without using a routing protocol of the routers. delete delete delete The method of claim 1,
The source server is a head office server connected to two or more branch offices,
the plurality of clients are clients in at least two or more intranets,
wherein the two or more intranets correspond to each of the two or more branch offices. A client for determining a shortest edge server, comprising:
a communication unit configured to communicate with a plurality of edge servers;
a storage configured to store a list of the plurality of edge servers; and
a control unit operatively connected to the communication unit and the storage unit;
The control unit is
and send a request for a list of the plurality of edge servers to an origin server;
send, based on the list of the plurality of edge servers, first data including a first TTL value to each of the plurality of edge servers;
configured to receive second data including a second TTL value associated with the first TTL value from each of the plurality of edge servers, and
determine, based on a difference between the first TTL value and the second TTL value, a shortest edge server of the client;
determining the shortest edge server of the client includes determining, as the shortest edge server, an edge server having a smallest difference between the first TTL value and the second TTL value;
When the number of edge servers having the smallest difference between the first TTL value and the second TTL value is two or more, determining the shortest edge server of the client includes:
acquiring data on a shortest edge server of another client among the plurality of clients; and
determining the shortest edge server of the client based on data for the shortest edge server of the other client, and
The client, wherein the shortest edge server of the other client is an edge server connected to the other client when requesting data for an edge server that was last connected to the other client or the shortest edge server of the other client.

Images