JP6570182B2 - ENUM cache setting system, ENUM authority server, and ENUM cache setting method - Google Patents

Description

  The present invention introduces a number portability system in which a service network (IP network) that provides IP (Internet Protocol) telephones is provided by a plurality of operators and these are interconnected. The present invention relates to an ENUM (E.164 Number Mapping) authoritative server and an ENUM cache setting method under specified conditions.

  2. Description of the Related Art Conventionally, in an IP network, an ENUM system has been proposed as a mechanism in which a device (SIP (Session Initiation Protocol) server or the like) in a communication carrier network associates a telephone number with a URI (Uniform Resource Identifier). In this ENUM system, a SIP server installed in a telecommunications carrier's network sends connection destination information (IP address, domain name, etc.) for the telephone number of a terminal (IP phone, etc.) to be connected to the ENUM server. And routing based on the information of the connection destination.

  When this SIP server makes an inquiry to the ENUM server every time it accepts a connection request from a terminal that it accommodates to another terminal, the access to the ENUM server becomes enormous and the load increases. The reason is that there are a plurality of communication carriers, a plurality of SIP servers are installed in the network of the communication carriers, and the number of terminals accommodated by one SIP server is large. This is because the ENUM server accepts access from the terminal. When the load on the ENUM server increases, the response time for inquiries from the SIP server becomes longer, and in the worst case, the ENUM server cannot respond, resulting in an increase in connection delay between terminals or a connection failure.

  Therefore, it has been proposed that the ENUM system also includes a cache mechanism (ENUM cache server) that stores information once queried, as used in DNS (Domain Name System) (Patent Document 1). reference). The SIP server that has received a connection request from a terminal in its own network to a connection destination terminal first makes an inquiry to the ENUM cache server. Then, if the ENUM cache server has accumulated the information of the connection destination, the ENUM cache server returns the information to the SIP server. On the other hand, if the ENUM cache server has not accumulated the connection destination information, the ENUM cache server makes an inquiry to the ENUM server storing the connection destination information, acquires the connection destination information, and cache data. And return to the SIP server. By doing so, the load on the ENUM server can be reduced. In the following description, the ENUM server is referred to as “ENUM authority server” as a server that receives an inquiry about connection destination information from the ENUM cache server.

  On the other hand, with the shift from a PSTN (Public Switched Telephone Network) network to an IP network, a mechanism of number portability in which a fixed telephone number can be freely carried between carriers in the IP network has been studied. (See Non-Patent Document 1).

  In the method described in Non-Patent Document 1, a database in which number portability information of each communication carrier is centrally managed is provided in an ENUM server (ENUM authority server) using a DNS mechanism, and the SIP server of each communication carrier is By accessing the ENUM server (ENUM authority server), it is resolved whether or not each telephone number has been transferred (ported out) to another network, and information on the connection destination is acquired for communication.

FIG. 8 is a diagram showing a conventional example when an ENUM cache server is employed to reduce the load on the ENUM server (ENUM authority server) as described above.
As shown in FIG. 8, first, a connection request message (in FIG. 8) from the terminal 1 (1a) in the 03-9999 band (IP telephone or the like) to the terminal 1 (1b) (IP telephone or the like) in the 0422-99 band. Is described as “connection request” (the same applies to other drawings), and is transmitted to the SIP server 30 (step S1).

  The SIP server 30 that has received the connection request message requests the ENUM cache server 20 to acquire connection destination information (such as a URI corresponding to the destination telephone number) for connection to the destination communication carrier (“connection” “Destination information request message” (described as “connection destination information request” in FIG. 8. The same applies to other drawings) (step S2).

  The ENUM cache server 20 confirms whether or not the connection destination information of the destination communication carrier is stored (cached) in its storage unit. If not stored, the ENUM cache server 20 connects to the ENUM authority server 10A. Inquiries of destination information ("transmission of connection destination information inquiry message". In FIG. 8, "connection destination information inquiry" is described. The same applies to other figures) (step S3).

  When the ENUM authority server 10A receives the inquiry of the connection destination information, the ENUM authority server 10A refers to its own database, extracts the connection destination information corresponding to the terminal 1 (1b) of the destination, and sends response information ( “Connection destination information inquiry response message” (described as “connection destination information inquiry response” in FIG. 8. The same applies to other figures) is transmitted (step S4).

  When the ENUM cache server 20 receives the response information, the ENUM cache server 20 stores (caches) the connection destination information and TTL (Time To Live: cache holding period) included in the response information in its own storage unit (step S5). Then, the ENUM cache server 20 transmits a connection destination information response message including the connection destination information (described as “connection destination information response” in FIG. 8; the same applies to other diagrams) to the SIP server 30 ( Step S6).

Note that the processing of steps S3 to S5 is not performed when the connection destination information corresponding to the receiving communication carrier is stored (cached) in the ENUM cache server 20, and the ENUM cache server 20 stores the storage destination ( The connection destination information that has been cached is acquired, and a connection destination information response message is transmitted to the SIP server 30 (step S6).
Further, the ENUM cache server 20 deletes the connection destination information stored (cached) when a predetermined holding period set by TTL elapses.

  When the SIP server 30 receives the connection destination information included in the connection destination information response message, the SIP server 30 makes a call connection to the terminal 1 (1b) in the 0422-99 band as the destination (step S7).

JP 2007-243564 A

"JJ-90.31 Carrier ENUM interconnection common interface" Information and Communication Technology Committee, August 27, 2015

However, the conventional method using the ENUM cache server has the following problems.
In the technology described in Non-Patent Document 1 (standardization technology), the TLL set in the ENUM cache server recommends a fixed time (60 seconds). When the ENUM cache server sets 60 seconds as the TTL, the connection destination The connection destination information is deleted 60 seconds after the information is cached.
Therefore, the conventional ENUM cache server holds the cache for a certain period of time even with connection destination information where the frequency of queries is low and a cache hit cannot be expected. Conversely, connection destination information with a high query frequency and a cache hit that can be expected is discarded in a certain time. In other words, the efficiency of cache hits was poor. For example, even in a situation where calls to the same telephone number are concentrated, the ENUM cache server deletes the cached connection destination information according to the TTL setting. Therefore, even when an inquiry to the same telephone number is received thereafter, the ENUM authority server is accessed again, and the processing load of the ENUM authority server increases. Therefore, in order to reduce the load on the ENUM authoritative server, it is necessary to improve the cache hit rate in the ENUM cache server.

  The present invention has been made in view of such a background, and an object of the present invention is to improve the cache hit rate of the ENUM cache server and reduce the load on the ENUM authority server.

  In order to solve the above-described problem, the invention described in claim 1 relates to an ENUM authority server that receives an inquiry about connection destination information corresponding to a telephone number of a destination terminal from an ENUM cache server, and a telephone number of the destination terminal. An ENUM cache setting system including a contract information DB (Database) server for storing contract information, wherein the contract information DB server has a large number of incoming calls in association with the telephone number of the destination terminal. A storage unit that stores contract information in which contract contents serving as an index of whether or not there are stored, and a control unit that transmits the contract information for each telephone number of the destination terminal to the ENUM authority server. The ENUM authority server receives the contract information, and the content of the contract, which is an indicator that the number of incoming calls is large, is included in the telephone number of the destination terminal. If the ENUM cache server is recorded, a TTL (Time To Live) value indicating a period during which the connection destination information is held is set to be longer than a predetermined reference value, and the number of incoming calls is small. A TTL setting unit configured to set the TTL value to be shorter than a predetermined reference value when the contract content serving as an index is registered; connection destination information corresponding to the telephone number of the destination terminal; When a storage unit that stores the set TTL value related to connection destination information and an inquiry about connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server are received, An ENUM cache comprising: an inquiry response unit that responds to the ENUM cache server with connection destination information corresponding to a telephone number and the set TTL value. The system was set as a new system.

The invention according to claim 3 is an ENUM authority server that accepts an inquiry of connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server, and associates it with the telephone number of the destination terminal. When contract information that stores contract details indicating whether the number of incoming calls is large or small is received, and the contract content that is an index indicating that the number of incoming calls is large is registered in the telephone number of the destination terminal In addition, a TTL value indicating a period during which the ENUM cache server retains the connection destination information is set to be longer than a predetermined reference value, and contract contents serving as an indicator that the number of incoming calls is small are registered. A TTL setting unit that sets the TTL value to be shorter than a predetermined reference value, connection destination information corresponding to the telephone number of the destination terminal, and the connection destination information. When a query for connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server is received from the storage unit that stores the set TTL value relating to the telephone number of the destination terminal, An ENUM authority server comprising: an inquiry response unit that responds to the ENUM cache server with corresponding connection destination information and the set TTL value.

The invention according to claim 5 is an ENUM cache setting method of an ENUM authority server that accepts an inquiry of connection destination information corresponding to a telephone number of a destination terminal from an ENUM cache server, wherein the ENUM authority server Receiving contract information in which contract details are stored in association with the telephone number of the destination terminal and indicating whether the number of incoming calls is large or small, and the telephone number of the destination terminal has a large number of incoming calls When a contract content serving as an index is registered, a TTL value indicating a period during which the ENUM cache server holds the connection destination information is set to be longer than a predetermined reference value, and the number of incoming calls is small. And when the contract content serving as an index of the registration is registered, the step of setting the TTL value to be shorter than a predetermined reference value; Storing the connection destination information corresponding to the last telephone number and the set TTL value relating to the connection destination information in the storage means; and the connection corresponding to the telephone number of the destination terminal from the ENUM cache server A step of responding to the ENUM cache server with connection destination information corresponding to the telephone number of the destination terminal and the set TTL value when an inquiry about destination information is accepted, This is the ENUM cache setting method.

  By doing so, the ENUM authority server can set an appropriate TTL value corresponding to the telephone number of the destination terminal based on the contract information. By transmitting this appropriate TTL value together with the connection destination information to the ENUM cache server, the cache hit rate of the ENUM cache server can be improved and the load on the ENUM authority server can be reduced.

  The invention according to claim 2 is an ENUM authority server that receives an inquiry about connection destination information corresponding to a telephone number of a destination terminal from an ENUM cache server, and a contract information DB that stores contract information regarding the telephone number of the destination terminal. A ENUM cache setting system comprising a server and a statistical information DB server for storing statistical information relating to the number of connection requests for each destination terminal, wherein the contract information DB server is a telephone of the destination terminal A storage unit that stores contract information in which contract contents that are an indicator of whether the number of incoming calls is large or small in association with a number, and the contract information for each telephone number of the destination terminal are stored in the ENUM authority. A control unit that transmits to the server, and the statistical information DB server provides statistical information regarding the number of connection requests of each of the destination terminals. A storage unit that stores the statistical information in association with the telephone number of the destination terminal, the ENUM authority server receives the contract information, and receives the incoming call When a contract content serving as an index indicating that the number of incoming calls is registered in the telephone number of the destination terminal, a TTL value indicating a period during which the ENUM cache server holds the connection destination information is determined from a predetermined reference value. A TTL setting unit configured to set the TTL value to be shorter than a predetermined reference value when a contract content serving as an index indicating that the number of incoming calls is small is registered; A storage unit that stores connection destination information corresponding to the telephone number of the destination terminal and the set TTL value related to the connection destination information, receives the statistical information, and has a large number of connection requests Or a TTL changing unit that changes the set TTL value depending on whether the call is received, and when the inquiry about the connection destination information corresponding to the telephone number of the destination terminal is received from the ENUM cache server, the incoming call An ENUM cache setting system comprising: an inquiry response unit that responds to the ENUM cache server with connection destination information corresponding to a telephone number of a destination terminal and the changed TTL value.

The invention according to claim 4 is an ENUM authority server that accepts an inquiry of connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server, and associates it with the telephone number of the destination terminal. The ENUM cache server receives contract information that indicates whether the number of incoming calls is large or small, and the contents of the contract that indicates the high number of incoming calls are registered in the telephone number of the destination terminal. TTL value indicating a period for holding the connection destination information is set to be longer than a predetermined reference value, and the TTL value is registered when a contract content serving as an index indicating that the number of incoming calls is small is registered. TTL setting unit for setting the connection destination information to be shorter than a predetermined reference value, connection destination information corresponding to the telephone number of the destination terminal, and the setting related to the connection destination information. A storage unit for storing the TTL value, and statistical information regarding the number of connection requests of each of the destination terminals, and a TTL change for changing the set TTL value depending on whether the number of connection requests is large or small And the connection destination information corresponding to the telephone number of the destination terminal and the changed TTL value when an inquiry about the destination information corresponding to the telephone number of the destination terminal is received from the ENUM cache server And an inquiry response unit that responds to the ENUM cache server.

The invention described in claim 6 is an ENUM cache setting method of an ENUM authority server that receives an inquiry about connection destination information corresponding to a telephone number of a destination terminal from the ENUM cache server, wherein the ENUM authority server includes the ENUM authority server, In association with the telephone number of the destination terminal, contract information that is an indicator of whether the number of incoming calls is large or small is received, and the content of the contract that serves as an index for the number of incoming calls is the telephone number of the destination terminal If registered, a TTL value indicating a period during which the ENUM cache server retains the connection destination information is set to be longer than a predetermined reference value, and the contract content serves as an indicator that the number of incoming calls is small Corresponding to the telephone number of the destination terminal and the step of setting the TTL value to be shorter than a predetermined reference value Storing the connection destination information and the set TTL value related to the connection destination information in the storage means, and receiving statistical information regarding the number of connection requests of each destination terminal, and the number of connection requests is large or small And changing the set TTL value, and when receiving an inquiry for connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server, the telephone of the destination terminal The ENUM cache setting method is characterized by executing the step of responding the connection destination information corresponding to the number and the changed TTL value to the ENUM cache server.

  In this way, the ENUM authority server can set the TTL value based on the contract information, and more appropriately change the TTL value based on the statistical information of the destination terminal. Therefore, the cache hit rate of the ENUM cache server can be further improved, and the load on the ENUM authority server can be reduced appropriately.

  In this way, the ENUM authority server can set an appropriate TTL value corresponding to the telephone number of the destination terminal based on the statistical information of the destination terminal. By transmitting this appropriate TTL value together with the connection destination information to the ENUM cache server, the cache hit rate of the ENUM cache server can be improved and the load on the ENUM authority server can be reduced.

  According to the present invention, the cache hit rate of the ENUM cache server can be improved, and the load on the ENUM authority server can be reduced.

It is a figure which shows the whole structure of the ENUM cache setting system containing the ENUM authority server which concerns on the 1st Embodiment of this invention. It is a figure which shows the data structural example of the contract information which concerns on the 1st Embodiment of this invention. It is a functional block diagram which shows the structural example of the ENUM authority server which concerns on the 1st Embodiment of this invention. It is a figure which shows the data structural example of the connection destination information table which concerns on the 1st Embodiment of this invention. It is a figure which shows the whole structure of the ENUM cache setting system containing the ENUM authority server which concerns on the 2nd Embodiment of this invention. It is a functional block diagram which shows the structural example of the ENUM authority server which concerns on the 2nd Embodiment of this invention. It is a figure which shows the whole structure of the ENUM cache setting system containing the ENUM authority server which concerns on the modification of the 2nd Embodiment of this invention. It is a figure which shows the prior art example at the time of employ | adopting an ENUM cache server in order to reduce the load of an ENUM server (ENUM authority server).

  Next, an ENUM cache setting system, an ENUM authority server, and an ENUM cache setting method in a mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described.

<First Embodiment>
First, the ENUM cache setting system 100 including the ENUM authority server 10 according to the first embodiment will be described.
FIG. 1 is a diagram showing an overall configuration of an ENUM cache setting system 100 including an ENUM authority server 10 according to the first embodiment of the present invention.
The ENUM authority server 10 according to the first embodiment is characterized in that the TTL setting for the connection destination information stored (cached) in the ENUM cache server 20 is performed based on the contract information of the telephone number.

As shown in FIG. 1, in the system including the ENUM authority server 10 according to the first embodiment, a contract information DB (DataBase) server 40 is connected to the ENUM authority server 10 in addition to the system configuration shown in FIG. It is characterized by being. The ENUM authority server 10 refers to the contract information 400 (FIG. 2 to be described later) stored in the contract information DB server 40, and receives the inquiry from the ENUM cache server 20 for connection destination information corresponding to the telephone number. TTL is optimally set based on a predetermined logic. For example, the ENUM authority server 10 refers to the contract information 400 and sets a long TTL for corporate users who frequently receive calls, or sets a short TTL for individual users. . In addition, the TTL of the user number subscribing to the additional service such as a representative number is set long, the TTL of the user number used for usage such as a call center is set long. That is, the ENUM authority server 10 according to the first embodiment is characterized in that the TTL setting time is optimally set based on the contract information 400.
This will be specifically described below.

As shown in FIG. 1, an ENUM cache setting system 100 according to the first embodiment of the present invention includes an ENUM authority server 10 connected to the ENUM cache server 20 and a contract information DB server 40 connected to the ENUM authority server 10. It is comprised including.
The ENUM authoritative server 10 receives an inquiry (connection destination information inquiry message) from the ENUM cache server 20, and receives connection destination information corresponding to the telephone number of the destination terminal stored by itself and a set time of the TTL (hereinafter referred to as “TTL”). Information including the “value” (sometimes referred to as “ENUM data”) is transmitted to the ENUM cache server 20 as response information (connection destination information inquiry response message). The ENUM cache server 20 stores the ENUM data as cache data, and deletes the ENUM data when a TTL setting time elapses according to the setting of the TTL value attached to the ENUM data.
The ENUM authority server 10 determines the setting of the TTL value corresponding to each telephone number based on the contract information 400 stored in the contract information DB server 40.

<< Contract Information DB Server 40 >>
The contract information DB server 40 according to the first embodiment of the present invention is a computer including an input / output unit, a storage unit, and a control unit (all not shown). The input / output unit includes a communication interface that transmits and receives information to and from the ENUM authority server 10 and the like. The storage unit includes storage means such as a hard disk or a flash memory, and stores user contract information 400 set in association with the registered telephone number (see FIG. 2). The control unit receives a reference request for the contract information 400 from the ENUM authority server 10 and transmits each piece of information of the contract information 400 stored in the storage unit to the ENUM authority server 10.

FIG. 2 is a diagram illustrating a data configuration example of the contract information 400 according to the first embodiment of the present invention.
The contract information 400 stores contract contents that are indicators of whether the number of incoming calls is large or small, in association with the telephone number of the destination terminal. Specifically, as shown in FIG. 2, the contract information 400 stores a user type 402 in association with at least the telephone number 401. As the user type 402, for example, “1” is registered when the contract user is an individual, and “2” is registered when the contract user is a corporation.

Further, in the contract information 400, contract contents such as an additional service 403, a usage application 404, and related information 405 may be registered in association with the telephone number 401.
The additional service 403 stores information such that the telephone number 401 is contracted with a “representative number” as an additional service, “incoming charge” as an additional service, and the like.
The usage 404 stores that the telephone number 401 is used as a “mail order” reception number, a “call center” reception number, and the like.
In the related information 405, information related to the user who has registered the telephone number 401 is registered. For example, the number of inquiry calls is expected to increase, such as news (recall information and service stop information) related to products sold by the user and services provided by the user, sales information of new products, ticket release date / time information, etc. Information is stored in this related information 405.

  The contract information DB server 40 receives a reference request for the contract information 400 from the ENUM authority server 10 at a predetermined time interval and refers to each information. Further, each time a record corresponding to one row of each telephone number 401 is newly registered, the contract information DB server 40 may transmit information on the record to the ENUM authority server 10.

Note that when registering each piece of information in the contract information 400, the network manager may also store weighting information corresponding to the contents of each contract. In this weighting information, a high value weight is set for information that is expected to have many connection requests to the telephone number 401.
For example, a weight “0” is set as an initial value for “individual” of the user type 402, and a weight “1” is set for “corporate”. A weight “3” is set for the “representative number” of the additional service 403, and a weight “5” is set for the incoming call charge. A weight “5” is set for “mail order” of usage 404, and a weight “5” is also set for the call center. A weight of “10” is set in the “required product collection news” in the related information 405. These weight values can be arbitrarily set by a network administrator or the like.

The contract information DB server 40 transmits each record of the contract information 400 to which the weighting information is attached to the ENUM authority server 10 as an initial value. Further, when the contents of the contract information 400 are changed, the contract information DB server 40 transmits a record of the contract information 400 including the changed contents to the ENUM authority server 10 .

≪ENUM authority server 10≫
Next, the ENUM authority server 10 of the ENUM cache setting system 100 will be described.
FIG. 3 is a functional block diagram showing a configuration example of the ENUM authority server 10 according to the first embodiment of the present invention.
The ENUM authority server 10 according to the first embodiment includes a connection destination information table 130 (see FIG. 4 to be described later), and receives call destination information (connection destination information inquiry message) from the ENUM cache server 20 ( ENUM data including the connection destination information and TTL corresponding to the telephone number of the destination terminal) is returned to the ENUM cache server 20 as a connection destination information inquiry response message. The ENUM authority server 10 is characterized by setting and storing an optimum TTL value based on the contract information 400 in association with each destination information in the connection destination information table 130.

Note that the ENUM authoritative server 10 is managed in a hierarchical structure (Tier0 to Tier2) as in the case of DNS. When performing name resolution for destination information, it manages Tier0 or Tier1 which is an upper layer. A query is recursively made from the ENUM authority server to the ENUM authority server that manages Tier2. In ENUM, each communication carrier manages an ENUM authority server belonging to Tier 2, and stores connection destination information corresponding to each terminal 1 in each number band (for example, area code). In the present embodiment, in order to simplify the description, an ENUM authority server belonging to Tier 2 managed by a communication carrier will be illustrated and described.
The ENUM authority server 10 includes an input / output unit 11, a control unit 12, and a storage unit 13, as shown in FIG.

  The input / output unit 11 inputs and outputs information with other devices and the like. For example, the input / output unit 11 transmits and receives information to and from the ENUM cache server 20 and the contract information DB server 40. The input / output unit 11 includes a communication interface that transmits and receives information via a communication line, and an input / output interface that inputs and outputs information between an input device such as a keyboard (not shown) and an output device such as a monitor. Composed.

The storage unit 13 is configured by a hard disk, a flash memory, a RAM (Random Access Memory), or the like.
The storage unit 13 stores a connection destination information table 130 and the like.

FIG. 4 is a diagram illustrating a data configuration example of the connection destination information table 130 according to the first embodiment of the present invention.
As illustrated in FIG. 4, the connection destination information table 130 stores connection destination information 132 and TTL 133 in association with the destination information 131.
The destination information 131 includes, for example, E.D. based on the telephone number of the destination terminal 1. Information obtained by converting the 164 number into the domain format of the ENUM protocol is stored. For example, the E.D. of the telephone number of the destination terminal (for example, 0422-99-1234). 164 numbers (+ 81-422-99-1234) are reversed, separated by dots, and added with “e164.arpa”, “e164.net”, etc. (in FIG. 4, “4.3.2.1.9.9.2.2 .4.1.8.e164.arpa ”) is stored as the destination information 131.

  The connection destination information 132 includes, for example, the E.D. A URI including the 164 number and the domain name (carrier_a) of the connection carrier is stored. Here, the domain indicated by “carrier_a” in the domain name means connection destination information of the own IP network. In addition, the domain indicated by “carrier_b” and “carrier_c” means the connection destination information of the IP network of another carrier, and that the telephone number of the destination terminal has been transferred (ported out) to the other network. (Refer to the record indicated by the symbol α in FIG. 4).

The TTL 133 stores a TTL value (cache retention period) associated with each destination information 131. The TTL 133 stores information determined based on the contract information 400 and the like by the TTL setting unit 121 in the control unit 12 described later.
Each record (for one line) corresponding to the destination information 131 in the connection destination information table 130 is the ENUM data described above.

  Returning to FIG. 3, the control unit 12 governs the overall processing executed by the ENUM authority server 10, and includes a TTL setting unit 121, a connection destination information search unit 122, and a connection destination information inquiry response unit 123 (inquiry response unit). Composed. The control unit 12 is realized, for example, when the CPU expands and executes a program stored in the storage unit 13 of the ENUM authority server 10 on the RAM.

  The TTL setting unit 121 refers to the contract information 400 stored in the contract information DB server 40, calculates the value of the TTL 133 corresponding to each destination information 131, and sets it in the connection destination information table 130 in the storage unit 13. To do. The TTL setting unit 121 may refer to the contract information 400 stored in the contract information DB server 40 at a predetermined time interval, or the contract information 400 newly registered or changed may be referred to as the contract information DB. You may make it receive from the server 40. FIG.

The TTL setting unit 121 determines a TTL value according to a predetermined logic. This predetermined logic is set based on the following policy, for example.
For the telephone number (destination information) of a corporate user who frequently receives calls, the TTL is set longer than a predetermined reference value. In addition, the TTL is set shorter than a predetermined reference value for the telephone number (destination information) of the individual user.
The telephone number (destination information) of the user who subscribes to the additional service of “representative number” is assumed to have a high incoming frequency, so the TTL is set to be long.
The telephone number (destination information) of the user who uses the additional service of “incoming call charge” is assumed to have a high incoming frequency, so the TTL is set to be long.
-Regarding usage, telephone numbers (destination information) such as "mail order", "call center", and "ticket sale" are assumed to have a high incoming frequency, so a long TTL is set.
Regarding the related information, when there is news related to the contract user (for example, news of product collection), the incoming frequency is assumed to be high, so the TTL is set long.

For example, the following predetermined logic is set in the TTL setting unit 121 based on the above policy.
The TTL setting unit 121 sets the TTL value for the telephone number of the corporate user type 402 to “60” seconds longer than a predetermined reference value (for example, “45” seconds). Also, the TTL for the telephone number of the user type 402 is set to “30” seconds, which is shorter than a predetermined reference value. Then, referring to the contract information 400, when the user has subscribed to “representative number” or “incoming call charge” of the additional service 403, “+60” seconds are added respectively. If the usage 404 is “mail order”, “call center” or the like, “+60” seconds are further added. Even when the related information 405 is registered, logic such as adding “+60” seconds is determined in advance. The TTL setting unit 121 calculates and determines the value of the TTL 133 based on the contents of the contract information 400 for each telephone number, and registers the value in the connection destination information table 130.

In addition, when the above-described weighting information is added to each piece of information in the contract information 400, the TTL setting unit 121 sets, for example, “+30” seconds as the TTL value for the weight “1”. Also good.
In this case, since the initial value of the individual user is the weight “0”, the value of TTL 133 is set to “30” seconds, “+30” is added to the corporate user with the weight “1”, and the value of TTL 133 is set to “ 60 ”seconds. When “representative number” is set as the additional service 403 and the weight is “3”, “+30” (seconds) × “3” is added, and “90” seconds are added to the initial value “30” seconds. The value “120” seconds is set as the value of TTL 133.
In this way, the TTL setting unit 121 can calculate the value of the TTL 133 based on the weighting information attached to the contract information 400.

  The TTL setting unit 121 cooperates with the contract information DB provided in the other network for ENUM data in which the telephone number of the destination terminal (the destination information) has been transferred (ported out) to the other network, The TTL value may be set with reference to the contract information. The same applies to the statistical information DB described later.

  In addition, the TTL setting unit 121 may receive input information of the contract information 400 directly from the network administrator, for example, via the input / output unit 11 and calculate the value of the TTL 133, or the TTL 133 from the network administrator. The input information of the set value (TTL value) may be received and set in the connection destination information table 130.

  When receiving the connection destination information inquiry message from the ENUM cache server 20 via the input / output unit 11, the connection destination information search unit 122 extracts the destination information attached to the connection destination information inquiry message. Then, the connection destination information search unit 122 refers to the connection destination information table 130 in the storage unit 13 and searches for the connection destination information 132 and the TTL 133 corresponding to the destination information 131. The connection destination information search unit 122 extracts ENUM data (connection destination information 132 and TTL 133) obtained as a result of the search, and outputs a processing instruction to the connection destination information inquiry response unit 123.

  The connection destination information inquiry response unit 123 (inquiry response unit) generates a connection destination information inquiry response message with the ENUM data (connection destination information 132 and TTL 133) extracted by the connection destination information search unit 122. Then, the connection destination information inquiry response unit 123 transmits the generated connection destination information inquiry response message to the ENUM cache server 20.

  As described above, according to the ENUM cache setting system 100 including the ENUM authority server 10 according to the first embodiment of the present invention, each incoming call is referred to by referring to the contract information 400 stored in the contract information DB server 40. An appropriate TTL value corresponding to the destination information can be set in the connection destination information table 130. The ENUM authority server 10 can transmit the appropriate TTL value together with the connection destination information to the ENUM cache server 20 for storage (cache). As a result, the cache hit rate of the ENUM cache server 20 can be improved, and the load on the ENUM authority server 10 can be reduced.

<Second Embodiment>
Next, the ENUM cache setting system 100a including the ENUM authority server 10a according to the second embodiment will be described.
FIG. 5 is a diagram showing an overall configuration of the ENUM cache setting system 100a including the ENUM authority server 10a according to the second embodiment of the present invention.
Compared to the ENUM cache setting system 100 according to the first embodiment shown in FIG. 1, the ENUM cache setting system 100 a is characterized by including a statistical information DB server 50 as shown in FIG. 5.

  The ENUM authority server 10a according to the second embodiment includes the TTL value for the connection destination information to be stored (cached) in the ENUM cache server 20, the contract information 400 of the telephone number (destination information), and the statistical information DB. It is set based on the statistical information 500 acquired from the server 50. The configuration and processing contents of the contract information DB server 40 are the same as those in the first embodiment, and a description thereof will be omitted here. The ENUM authority server 10a refers to the contract information 400 stored in the contract information DB server 40 and sets a TTL for each destination information, and then the statistical information 500 stored in the statistical information DB server 50. Based on the above, the TTL setting time is changed more optimally.

≪Statistical information DB server 50≫
The statistical information DB server 50 according to the second embodiment of the present invention is a computer configured to include an input / output unit, a storage unit, and a control unit (all not shown). The input / output unit includes a communication interface for transmitting / receiving information to / from the ENUM authority server 10a and the like. The storage unit includes storage means such as a hard disk or a flash memory, and stores statistical information 500 associated with each registered telephone number or telephone number band. The control unit collects the statistical information 500 and stores it in the storage unit. And a control part receives the reference request | requirement of the statistical information 500 from the ENUM authority server 10a, and transmits each information of the statistical information 500 memorize | stored in the memory | storage part to the ENUM authority server 10a.

The statistical information stored in the storage unit of the statistical information DB server 50 stores, for example, the following information.
・ Number of connection requests for each incoming phone number (number of calls)
-Frequency information for a predetermined period of the number of connection requests (number of calls) for each incoming phone number For example, information on the number of incoming calls, time zone, time (day of the week, month, season, event)-For each incoming phone number, Call volume information for each region (each phone number)

The statistical information DB server 50 collects information set by the network administrator in advance among these statistical information. The statistical information DB server 50 can acquire such information from, for example, each SIP server 30 or a network management device (not shown) that manages the entire network. Note that the inquiry about the connection destination information to the ENUM authority server 10a is not only from the SIP server 30 in the own network as shown in FIG. 5, but also the inquiry about the connection destination information from another IP network. Information such as the number of inquiries from other networks can also be acquired from a network management device (not shown) or the like.
The statistical information DB server 50 receives a reference request from the ENUM authority server 10a at predetermined time intervals, and transmits the collected statistical information to the ENUM authority server 10a.

<< ENUM authority server 10a >>
Next, the ENUM authority server 10a of the ENUM cache setting system 100a will be described.
FIG. 6 is a functional block diagram showing a configuration example of the ENUM authority server 10a according to the second embodiment of the present invention.
The difference from the configuration of the ENUM authority server 10 according to the first embodiment shown in FIG. 3 is that a TTL changing unit 124 is provided in the control unit 12a. Other configurations have the same functions, and thus the same names and the same reference numerals are given, and descriptions thereof are omitted.

  The TTL changing unit 124 changes the TTL value set in the connection destination information table 130 by the TTL setting unit 121 with reference to the statistical information 500 received from the statistical information DB server 50 based on a predetermined logic.

  For example, when the TTL changing unit 124 receives the statistical information of “number of connection requests for each incoming telephone number (number of telephone calls)”, the TTL is increased for the telephone number (destination information) with a large number of telephone calls. Change to For example, a value obtained by adding “+60” seconds to the current TTL value is calculated and set. In addition, based on the statistical information, the TTL is set to be long (for example, “+60” seconds are added) for the time when the frequency of telephone calls is high and the time zone when there are many calls. On the other hand, the TTL is set short (for example, it is reduced as “−30 seconds”) in the time / time zone when the frequency of the telephone call is low.

  The TTL changing unit 124 may increase or decrease the TTL value for each region (area), that is, for each telephone number band. For example, in the event that a catastrophic disaster occurs, the number of incoming calls in the area (area) (for example, the 0422-99 telephone number band) increases rapidly. Extend significantly (for example, set to “3600” seconds). Also, the TTL changing unit 124 sets a long TTL for an incoming telephone number or telephone number band exceeding a predetermined call volume based on the statistical information 500 received from the statistical information DB server 50.

  As described above, according to the ENUM cache setting system 100a including the ENUM authority server 10a according to the second embodiment of the present invention, each incoming call is referred to by referring to the contract information 400 stored in the contract information DB server 40. It is possible to appropriately change (adjust) the TTL based on the statistical information 500 of the telephone number that is the destination after appropriately setting the TTL setting time of the destination information. Therefore, the cache hit rate of the ENUM cache server 20 can be further improved, and the load on the ENUM authority server 10a can be appropriately reduced.

<Modification>
Next, a modification of the ENUM cache setting system 100a including the ENUM authority server 10a according to the second embodiment will be described.
FIG. 7 is a diagram showing an overall configuration of an ENUM cache setting system 100b including an ENUM authority server 10b according to a modification of the second embodiment of the present invention.
Compared to the ENUM cache setting system 100a of the second embodiment shown in FIG. 5, the ENUM cache setting system 100b according to the modification is different in that the contract information DB server 40 is not provided as shown in FIG.
In this case, the TTL setting unit 121 of the ENUM authority server 10b previously sets, for example, “60” seconds as the TTL value (initial value of all TTLs) of the connection destination information table 130. Then, the TTL changing unit 124 acquires (refers to) the statistical information 500 from the statistical information DB server 50 to change the value of the TTL 133 in the connection destination information table 130.

  Also in this way, according to the ENUM cache setting system 100b including the ENUM authoritative server 10b according to the modification of the second embodiment of the present invention, each of the destination numbers is based on the statistical information 500 of the telephone number as a destination. It is possible to appropriately change (adjust) the TTL setting time of the destination information. Therefore, the cache hit rate of the ENUM cache server 20 can be improved, and the load on the ENUM authority server 10b can be appropriately reduced.

  In the description of each embodiment of the present invention, as shown in FIGS. 1 and 5, the contract information 400 is stored in the contract information DB server 40 which is a separate device from the ENUM authority servers 10 and 10a. As explained. However, the contract information 400 may be provided in the ENUM authority servers 10 and 10a. In addition, as illustrated in FIGS. 5 and 7, the statistical information 500 has been described as being stored in the statistical information DB server 50, which is a separate device from the ENUM authority servers 10 a and 10 b. However, the ENUM authority servers 10a and 10b may include the statistical information 500.

  Furthermore, in the present embodiment, the ENUM authority servers 10, 10a, and 10b and the ENUM cache server 20 have been described as separate devices. However, by providing the ENUM authority servers 10, 10a, and 10b with a cache function, the ENUM authority server 10 , 10a, 10b may be configured with one housing.

1 terminal 10, 10a, 10b ENUM authority server 11 input / output unit 12 control unit 13 storage unit 20 ENUM cache server 30 SIP server 40 contract information DB server 50 statistical information DB server 100, 100a, 100b ENUM cache setting system 121 TTL setting unit 122 connection destination information search unit 123 connection destination information inquiry response unit (inquiry response unit)
124 TTL changing unit 130 connection destination information table 400 contract information 500 statistical information

Claims (6)

An ENUM configured to include an ENUM authority server that receives an inquiry about connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server, and a contract information DB server that stores contract information regarding the telephone number of the destination terminal. A cache setting system, wherein the contract information DB server is
A storage unit that stores contract information in which contract contents that are an indicator of whether the number of incoming calls is large or small are stored in association with the telephone number of the destination terminal.
A control unit that transmits the contract information for each telephone number of the destination terminal to the ENUM authority server,
The ENUM authority server
A period during which the ENUM cache server retains the connection destination information when the contract information that receives the contract information and a contract content that indicates that the number of incoming calls is large is registered in the telephone number of the destination terminal. When a TTL (Time To Live) value is set to be longer than a predetermined reference value, and the contract content serving as an index indicating that the number of incoming calls is small is registered, the TTL value is set higher than the predetermined reference value. TTL setting unit for setting so as to be shorter,
A storage unit that stores connection destination information corresponding to the telephone number of the destination terminal and the set TTL value related to the connection destination information;
When receiving an inquiry about connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server, the connection destination information corresponding to the telephone number of the destination terminal and the set TTL value are obtained. An inquiry response unit responding to the ENUM cache server;
An ENUM cache setting system comprising: An ENUM authority server that receives an inquiry about connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server, a contract information DB server that stores contract information regarding the telephone number of the destination terminal, and a connection to each destination terminal A statistics information DB server for storing statistics information on the number of requests, and an ENUM cache setting system comprising:
The contract information DB server
A storage unit that stores contract information in which contract contents that are an indicator of whether the number of incoming calls is large or small are stored in association with the telephone number of the destination terminal.
A control unit that transmits the contract information for each telephone number of the destination terminal to the ENUM authority server,
The statistical information DB server
A storage unit for storing statistical information regarding the number of connection requests of each of the destination terminals;
A control unit that transmits the statistical information to the ENUM authority server in association with the telephone number of the destination terminal;
The ENUM authority server
A period during which the ENUM cache server retains the connection destination information when the contract information that receives the contract information and a contract content that indicates that the number of incoming calls is large is registered in the telephone number of the destination terminal. When the TTL value is set to be longer than a predetermined reference value, and the contract contents serving as an index indicating that the number of incoming calls is small, the TTL value is set to be shorter than the predetermined reference value. A TTL setting unit to be set;
A storage unit that stores connection destination information corresponding to the telephone number of the destination terminal and the set TTL value related to the connection destination information;
A TTL changing unit that receives the statistical information and changes the set TTL value according to whether the number of connection requests is large or small;
When receiving an inquiry about connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server, the connection destination information corresponding to the telephone number of the destination terminal and the changed TTL value, An inquiry response unit responding to the ENUM cache server;
An ENUM cache setting system comprising: An ENUM authority server that receives an inquiry about connection destination information corresponding to a telephone number of a destination terminal from an ENUM cache server,
It receives contract information storing contract details that is an indicator of whether the number of incoming calls is large or small in association with the telephone number of the destination terminal, and the telephone number of the destination terminal has a large number of incoming calls When a contract content serving as an index of the registration is registered, a TTL value indicating a period during which the ENUM cache server holds the connection destination information is set to be longer than a predetermined reference value, and the number of incoming calls is small. A TTL setting unit configured to set the TTL value to be shorter than a predetermined reference value when contract contents serving as an index of the registration are registered;
A storage unit that stores connection destination information corresponding to the telephone number of the destination terminal and the set TTL value related to the connection destination information;
When receiving an inquiry about connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server, the connection destination information corresponding to the telephone number of the destination terminal and the set TTL value are obtained. An inquiry response unit responding to the ENUM cache server;
An ENUM authoritative server characterized by comprising: An ENUM authority server that receives an inquiry about connection destination information corresponding to a telephone number of a destination terminal from an ENUM cache server,
Corresponding contract information that is an indicator of whether the number of incoming calls is large or not in the telephone number of the destination terminal, receiving contract information that is an indicator of whether the number of incoming calls is large or small in association with the telephone number of the destination terminal Is registered such that the ENUM cache server sets a TTL value indicating a period during which the connection destination information is held to be longer than a predetermined reference value, and serves as an indicator that the number of incoming calls is small. A TTL setting unit configured to set the TTL value to be shorter than a predetermined reference value when content is registered;
A storage unit that stores connection destination information corresponding to the telephone number of the destination terminal and the set TTL value related to the connection destination information;
A TTL changing unit that receives statistical information regarding the number of connection requests of each destination terminal and changes the set TTL value depending on whether the number of connection requests is large or small;
When receiving an inquiry about connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server, the connection destination information corresponding to the telephone number of the destination terminal and the changed TTL value, An inquiry response unit responding to the ENUM cache server;
An ENUM authoritative server characterized by comprising: An ENUM cache setting method for an ENUM authority server that receives an inquiry about connection destination information corresponding to a telephone number of a destination terminal from an ENUM cache server,
The ENUM authority server
It receives contract information storing contract details that is an indicator of whether the number of incoming calls is large or small in association with the telephone number of the destination terminal, and the telephone number of the destination terminal has a large number of incoming calls When a contract content serving as an index of the registration is registered, a TTL value indicating a period during which the ENUM cache server holds the connection destination information is set to be longer than a predetermined reference value, and the number of incoming calls is small. When the contract content serving as an index is registered, the TTL value is set to be shorter than a predetermined reference value;
Storing in a storage means connection destination information corresponding to the telephone number of the destination terminal and the set TTL value relating to the connection destination information;
When receiving an inquiry about connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server, the connection destination information corresponding to the telephone number of the destination terminal and the set TTL value are obtained. Responding to the ENUM cache server;
ENUM cache setting method, characterized in that An ENUM cache setting method for an ENUM authority server that receives an inquiry about connection destination information corresponding to a telephone number of a destination terminal from an ENUM cache server,
The ENUM authority server
Corresponding contract information that is an indicator of whether the number of incoming calls is large or not in the telephone number of the destination terminal, receiving contract information that is an indicator of whether the number of incoming calls is large or small in association with the telephone number of the destination terminal Is registered such that the ENUM cache server sets a TTL value indicating a period during which the connection destination information is held to be longer than a predetermined reference value, and serves as an indicator that the number of incoming calls is small. When the content is registered, setting the TTL value to be shorter than a predetermined reference value;
Storing in a storage means connection destination information corresponding to the telephone number of the destination terminal and the set TTL value relating to the connection destination information;
Receiving statistical information regarding the number of connection requests of each of the destination terminals, and changing the set TTL value according to whether the number of connection requests is large or small;
When receiving an inquiry about connection destination information corresponding to the telephone number of the destination terminal from the ENUM cache server, the connection destination information corresponding to the telephone number of the destination terminal and the changed TTL value, Responding to the ENUM cache server;
ENUM cache setting method, characterized in that

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