JP2013115530A - Ras device and line closing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a remote access service (RAS) device and a line closing method that achieve lower power consumption and longer life in data communication using a primary group speed interface accommodating a plurality of subscribers by physically multiplexing one line.SOLUTION: A remote access service (RAS) device 1 comprises: a plurality of T1 interface units 20 respectively corresponding to N T1 interfaces (primary group speed interface) 5 connected with an ISDN exchange; an IP interface unit 30 connecting with an IP network; a control unit 10 which manages the call connection state between the ISDN and the IP network and performs power supply control of a line; and line management information 100 for storing the utilization state of each line. The control unit 10 of the RAS device 1 refers to the line management information 100, moves a call on a line having a large execution performance of data communication to a line having a smaller execution performance among the lines of the N T1 interfaces 5, and stops power supply to the line when all calls are moved.

Description

  The present invention uses a primary group speed interface line of an exchange constituting a conventional telephone network (legacy network) to supply power to the line circuit according to the usage status of the interface line circuit of the RAS (Remote Access Service) device. The present invention relates to a device for stopping or starting.

  Conventionally, in an optical communication system, when data transmission / reception between a subscriber unit and a carrier device is stopped, power supply to the optical transmission / reception circuit of the subscriber unit is stopped to save power and extend the life of the unit. The technique which implement | achieves is disclosed (refer patent document 1).

JP 2010-278524 A

  The communication network used for telephone and Internet connection is a situation where networks of different protocols from analog telephone network, ISDN (Integrated Services Digital Network), and IP (Internet Protocol) network are mixed. In the direction to be integrated into. Therefore, a device that intervenes between a legacy network that has been used for a long time and has been used aging, and an IP network that has been actively used in recent years is indispensable as an indispensable product for the time being.

  On the other hand, ecological guidelines in the ICT (Information and Communication Technology) field have been formulated by the Telecommunications Industry Association, and in the future, greenhouse gas emissions are being reduced as one of the measures to prevent global warming. In producing the product, power consumption is required to be as low as possible. In particular, communication devices are electronic devices with large power consumption, and it is necessary to incorporate positive power saving measures.

  In such a situation, there is a problem of power saving feasibility of individual legacy components that constitute the interface of the legacy network. Legacy parts were designed before ecology was required, and were not made from the viewpoint of reducing power consumption. It is extremely difficult to start adding new functions such as power reduction.

  Therefore, considering the technology described in Patent Document 1, the communication device realized in Patent Document 1 performs power saving in units of one subscriber line. The communication line that is the subject of the present invention is one in which a plurality of subscribers such as a primary group speed interface in ISDN are physically multiplexed on a single metal line for continuous connection communication. It is efficient for a communication device on the telecommunications carrier side that accommodates the primary group speed interface to use one circuit for one primary group speed interface. The standard design was to assign one circuit. Therefore, even if data communication of one subscriber is stopped, the line cannot be stopped if data communication of other subscribers is continued.

  The present invention has been made in view of such a background, and in the data communication using the primary group speed interface that accommodates a plurality of subscribers by physically multiplexing one line, It is an object of the present invention to provide a RAS apparatus and a line blocking method that realize low power consumption and long life.

  In order to solve the above-described problem, the RAS apparatus of the present invention includes a plurality of primary group speed interface units (T1 interface units) respectively corresponding to N primary group speed interfaces (T1 interfaces) connected to the ISDN switch. , An IP interface unit connected to the IP network, a control unit that manages a call connection state between the ISDN and the IP network, and controls power supply of the line, and line management information that stores a use status of each line. Then, the control unit of the RAS apparatus refers to the line management information, and among the N primary group speed interface (T1 interface) lines, calls for lines with a large data communication performance record are used for lines with a small operation record. It is characterized in that the power supply to the line is stopped when all calls have been moved.

  According to the present invention, in data communication using a primary group speed interface that accommodates a plurality of subscribers by physically multiplexing one line, RAS that realizes low power consumption and long life. An apparatus and a line blocking method can be provided.

It is a figure which shows the structural example of the network system containing the RAS apparatus which concerns on this embodiment. It is a block diagram which shows the structural example of the RAS apparatus which concerns on this embodiment. It is a figure which shows an example of the data structure of the line management information which concerns on this embodiment. It is a figure which shows an example of a data structure of the time slot management information which concerns on this embodiment. It is a figure which shows an example of the data structure of the line | wire (call) movement information which concerns on this embodiment. It is a figure which shows an example of the data structure of the connection relation management information which concerns on this embodiment. It is a figure which shows the call control sequence in the case of a terminal calling and connecting to a server in the network system containing the RAS apparatus which concerns on this embodiment. It is a flowchart which shows the flow of the line | wire block | closing process of the RAS apparatus which concerns on this embodiment. In this embodiment, it is a figure which shows the control sequence in case a call is made in the middle of the block | close of a line. In this embodiment, it is a flowchart which shows the connection destination determination process performed when a call is made in the middle of block | closing of a line | wire. It is a figure for demonstrating the connection sequence of B channel (Bch) communication and IP communication in FIG. In this embodiment, it is a figure which shows the control sequence when a re-call is made about the call disconnected by the line | wire block | closing process.

Next, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described in detail with reference to the drawings as appropriate.
In the present embodiment, an example of a method for reducing power consumption and extending the life of a RAS (Remote Access Service) device 1 that converts TDM (Time Division Multiplexing) data into IP packets in always-on ISDN communication. explain.

FIG. 1 is a diagram illustrating a configuration example of a network system including a RAS apparatus 1 according to the present embodiment.
As shown in FIG. 1, in this network system, a RAS device 1 is connected to an ISDN switch 4 via N T1 interfaces (primary group speed interfaces) 5, and on the other hand, a LAN (Local Area Network) cable or the like. Is connected to the IP network 50 via the IP interface 6 realized in the above. The ISDN exchange 4 is one of the elements constituting the telephone network 40 and accommodates a terminal 2 such as a personal computer via a TA (Terminal Adapter) 3. The IP network 50 is provided with a server 7 that provides various services. For example, information content can be browsed. The RAS device 1 is also connected to a RADIUS (Remote Authentication Dial In User Server) server and an LNS (L2TP Network Server) (both not shown) for establishing a connection with the IP network 50 (details are given below). Refer to FIG. 11 to be described later).

  The RAS device 1 performs mutual conversion between TDM data and IP packets in order to provide Internet services to the terminal 2. In the present invention, the RAS device 1 according to the present embodiment described below reduces power consumption by temporarily disconnecting a call connection with a terminal 2 that is always connected. When a reconnection request from 2 is generated, the RAS device 1 holds connection information of the disconnected call, so that reconnection can be performed smoothly and an IP service can be provided.

  The primary group speed interface includes various types of lines such as a T1 interface and an E1 interface. In the present embodiment, the line is described as the T1 interface 5. When the present invention is applied to other types of primary group speed interfaces, it can be realized by changing the number of time slots corresponding to each.

Next, the RAS device 1 according to the present embodiment will be described.
FIG. 2 is a block diagram illustrating a configuration example of the RAS apparatus 1 according to the present embodiment.

As shown in FIG. 2, the RAS device 1 includes a T1 interface unit 20 connected to each of N T1 interfaces (primary group speed interfaces) 5, an IP interface unit 30 connected to the IP interface 6, and a control. And a storage unit (not shown) for storing line management information 100, time slot management information 200, line (call) movement information 300, and connection relationship management information 400.
The RAS apparatus 1 moves a call of a line with a large data communication operation record to a line with a small operation record among the N T1 interface 5 lines, and when all calls finish moving, Stop energization. In addition, the RAS device 1 can easily perform connection when a re-call is made by holding connection information about a call that is temporarily disconnected to move a line.
Each configuration will be specifically described below.

  The T1 interface units 20 (# 1 to #N) correspond to N T1 interfaces (primary group speed interfaces) 5 (# 1 to #N) connected to the ISDN switch 4 respectively. An interface unit 20 (# 1 to #N) is provided.

  The IP interface unit 30 includes an interface for connecting to the IP network 50 through the IP interface 6.

The storage unit (not shown) of the RAS device 1 stores line management information 100, time slot management information 200, line (call) movement information 300, and connection relationship management information 400.
Note that the storage unit includes storage means such as a RAM (Random Access Memory), a hard disk, and a flash memory.

When the control unit 10 of the RAS device 1 reduces power consumption, the line management information 100 can be energized and stopped on which line of the T1 interface 5 (hereinafter sometimes referred to as “T1 interface line”). This is information to be referred to when determining.
FIG. 3 is a diagram illustrating an example of a data configuration of the line management information 100 according to the present embodiment.

As shown in FIG. 3, the line management information 100 includes, as its data items, information on use or nonuse for each time slot (TS) number 120, the number of used TSs 130, the number of remaining TSs, in association with the line number 110. 131, accumulated energization time 140, final energization accumulation time 141, mean square 150, rank 151 based on mean square, line status 160, and energization status 161 are stored. These pieces of information are updated by a management information updating unit 13 (see FIG. 2) described later of the control unit 10 at predetermined time intervals or when any one of calls is disconnected.
In the description after FIG. 3, the number of lines (N) of the T1 interface 5 will be described as N = 8 in consideration of simplification of the description and ease of understanding.

  In the time slot (TS) number 120, “1” is stored in the currently used time slot and “0” is stored in the currently unused time slot for each time slot (TS1 to TS23) of each line. Remembered.

The number of used TS 130 stores the number of currently used time slots (TS) based on the information of TS1 to TS23 of the TS number 120.
The remaining TS number 131 stores the number of currently unused time slots (TS) based on the information of TS1 to TS23 of the TS number 120.
The usage state of the time slot in the claims is a concept including information on use or non-use for each time slot (TS) number 120, information on the number of used TSs 130, and the number of remaining TSs 131.

  In the cumulative energization time 140, the energization time from the start of energization to the present is stored for each line. For example, the energization time after the energization of the line with the line number 110 of “1” is currently “4200” seconds, indicating that energization is ongoing. When the line number 110 is “2”, the energization state 161 described later is “OFF”, indicating that the current energization time 140 is “OFF” and the accumulated energization time 140 has stopped at “2700” seconds. Yes.

The last energization accumulated time 141 stores, for each line, the accumulated energization time of that line when the energization was last stopped. For example, for the line with the line number 110 of “2”, in addition to “2700” seconds, which is the accumulated energization time 140 when the energization was last stopped, “300” stored in the last energization accumulated time 141 before the update is stored. “3000” seconds including “second” (not shown) are stored as the final energization accumulated time 141. That is, the final energization accumulated time 141 is updated every time the energization of the line is stopped, and indicates the total energization time of the line.
The energizing time in the claims is a concept including the accumulated energizing time 140 and the final energizing accumulated time 141.

In the mean square 150, a mean square 150 having the remaining TS number 131 and the cumulative energization time 140 as parameters is stored. In the present embodiment, the mean square 150 is used as an index of the operation performance of the line, and in the rank 151 which is the next data item, the calculated value of the mean square 150 is small from the line (the operation result is small). The order is determined in the order of the line with the largest calculated value (the largest operation record).
Note that the calculation to the root mean square 150 will be described in the management information update unit 13 to be described later of the control unit 10.

  In the rank 151, ranks that are ranked higher in order from the smallest calculated value of the root mean square 150 are stored. For example, since the line number 110 is “7”, the root mean square 150 is the smallest, so “1” is stored in the rank 151. Also, the line number 110 is “6”, and the root mean square 150 is the largest, so “8” is stored in the rank 151. The order 151 is referred to when the line block processing unit 11 described later of the control unit 10 selects a line to be blocked.

The line status 160 stores whether the current line status is “active”, “blocked”, or “in the process of blocking”. Note that “in the middle of blocking” indicates that the line blocking processing unit 11 described later after the control unit 10 is executing the line blocking process (details will be described later).
In the energization state 161, “ON” is stored when the line is energized, and “OFF” is stored when the energization is stopped.

Returning to FIG. 2, the time slot management information 200 is information for managing a unique telephone number assigned to each time slot (TS), a current use state of the time slot, and the like.
FIG. 4 is a diagram illustrating an example of a data configuration of the time slot management information 200 according to the present embodiment. As shown in FIG. 4, the time slot management information 200 includes a unique telephone number 203, a data reception last time 204, and a current time in association with the time slot (TS) number 202 of the line number 201 of the T1 interface 5. Each information of the difference 205 and the TS state 206 is stored.

  The unique telephone number 203 stores a unique telephone number set in advance in the telephone network 40 for each time slot of each line.

The data reception last time 204 stores the last time when the reception of data was detected for each time slot. For example, a time slot in which the line number 201 is “1” and the TS number 202 is “2” indicates that the data reception last time 204 is November 01, 20:51:50.
Note that this data reception final time 204 stores “-” when the TS state 206 described later is “communication”, and stores “0” when the TS state 206 is “free”.

The difference 205 between the current time stores the difference between the data reception last time 204 and the current time. For example, “2500” seconds are stored as the difference between the data reception last time 204 and the current time in the difference 205 from the current time of the time slot whose line number 201 is “1” and the TS number 202 is “2”. Is done.
The difference 205 from the current time is stored as “-” when the TS state 206 described later is “communication”, and is stored as “0” when the TS state 206 is “free”. .

The TS state 206 stores whether each time slot is in a “communication”, “empty”, or “no communication data” state. Here, “no communication data” means a state where communication is being performed but no data is exchanged. Specifically, the management information update unit 13 described later of the control unit 10 sets a predetermined threshold, for example, “5000” seconds, refers to the value of the difference 205 from the current time, and compares the difference 205 with the current time. When the value is less than “5000” seconds, the TS state 206 is set to “no communication data (communication is performed but no data is exchanged)”, and there is no data exchange exceeding the threshold of “5000” seconds. In this case, the TS state 206 is set to “free”.
This TS state 206 is referred to when the line block processing unit 11 to be described later of the control unit 10 performs the line block process, and the TS state 206 is “no communication data (during communication but no data exchange)”. For the call in the time slot, the line block processing unit 11 performs a process of temporarily disconnecting the call in order to move the call to another line.

  The data reception final time 204, the difference 205 from the current time, and the TS state 206 are monitored by the management information updating unit 13 described later of the control unit 10 by monitoring each T1 interface unit 20 (# 1 to #N). Update.

Returning to FIG. 2, in the line (call) movement information 300, when the energization of the line of the T1 interface 5 is stopped, the call of the time slot of the line to be de-energized is changed to the time slot of the line where the energization is continued. Information to be moved is stored.
FIG. 5 is a diagram showing an example of a data configuration of the line (call) movement information 300 according to the present embodiment. As shown in FIG. 5, the line (call) movement information 300 includes “time slot (TS) usage status” (information shown in the upper row) and “movement” for each line number and each time slot (TS) of the line. "Destination or source" (information shown in the lower row).

  For example, as in the first time slot (TS01) of the sixth line, “1” (in use) is stored in the “time slot (TS) usage status” column in the upper row, and “movement destination or movement” in the lower row. When “7/1” is stored in the “original” column, this indicates that the call of the time slot is moved to the first time slot (TS01) of the seventh line. Also, as in the first time slot (TS01) of the seventh line, “0” (unused) is stored in the “time slot (TS) usage status” column in the upper stage, and “movement destination or movement” in the lower stage. When “6/1” is stored in the “original” column, it indicates that the call of the time slot moves from the first time slot of the sixth line. That is, when information is entered in the lower part of the time slot of each line, it is in a reserved state and no other call connection processing is performed.

  Note that this line (call) movement information 300 is stored in the other line as the destination of the call in the time slot of the line being blocked when the line block processing unit 11 described later on the control unit 10 performs the line block process. Referenced when determining the time slot. Then, the line block processing unit 11 updates the information of this line (call) movement information 300 by determining the time slot of the line to which the call of the time slot of the line to be blocked is moved (details will be described later). .

Returning to FIG. 2, in the connection relationship management information 400, when stopping energization of the line of the T1 interface 5, the connection required when the call of the time slot is moved to the time slot of another energized line. Information is stored.
FIG. 6 is a diagram illustrating an example of a data configuration of the connection relationship management information 400 according to the present embodiment. As shown in FIG. 6, the connection relation management information 400 includes a connection source telephone number 401 of a connection source (calling terminal 2), a connection source IP address 402, a connection destination IP address 403, and a re-calling time. The line number / TS number 404 (described as “line / TS” in FIG. 6) is stored.

  The connection relation management information 400 is connection information indicating which terminal 2 was connected to which server 7 (see FIG. 1) when moving the call of the time slot to another line to stop energization of the line. Is for holding. Then, the calling telephone number (connection source telephone number 401) and the IP address of the server used by the call by the telephone number are stored in association with each other, and the telephone number is connected at the next connection ( By storing the line number and time slot (TS) number of the T1 interface 5 used at the time of re-calling, the IP between the terminal 2 and the server 7 at the time of re-calling from the terminal 2 after stopping energization Protocol processing such as address exchange is simplified or omitted.

  The connection relationship management information 400 is generated when the line block processing unit 11 of the control unit 10 disconnects the call in the time slot of the line to be blocked during the line block process. Then, the management information update unit 13 performs a deletion process on information that is not used again and is not used even after a predetermined time. Further, when there is a re-call from the terminal 2, the line control unit 12 of the control unit 10 refers to the connection relation management information 400, thereby omitting the protocol processing between the terminal 2 and the server 7. This makes it possible to quickly resume communication (details will be described later).

Returning to FIG. 2, the control unit 10 controls the entire RAS apparatus 1 and includes a line block processing unit 11, a line control unit 12, and a management information update unit 13.
The function of the control unit 10 of the RAS device 1 is, for example, that a CPU (Central Processing Unit) develops and executes a program stored in a storage unit (not shown) of the RAS device 1 in a memory such as a RAM. It is realized with.

The line blockage processing unit 11 refers to the line management information 100 (FIG. 3), and calls that are connected in order from the line with the larger operation record (the line with the lowest mean square rank 151) is the line with the smaller operation record. When the call disconnection is completed for all the calls accommodated by the line having a large operation record, the line blocking process for stopping energization of the line is executed.
The line blockage processing unit 11 refers to the root mean square rank 151 of the line management information 100, sets the line with the smallest operation record as the first line and the line with the largest operation record as the Nth (here Then, the process of moving the call of the Nth line to a line with a small operation record is performed. At this time, the line block processing unit 11 refers to the line (call) movement information 300 (FIG. 5) and determines the time slot of the line to which the call to be disconnected is moved. Then, the line block processing unit 11 refers to the time slot management information 200 (FIG. 4), and among the corresponding lines, the time slot whose TS state 206 is “no communication data (communication but no data exchange)” The process of disconnecting the call is sequentially performed. Subsequently, the line block processing unit 11 generates data of the connection relationship management information 400 (FIG. 6) for the disconnected call in preparation for a re-call from the terminal 2. Similarly, the line block processing unit 11 continues the process so as to move a call on a lower line having a higher operation record to a higher line having a lower operation record.
Specifically, it will be described in detail with reference to FIG.

The line control unit 12 is responsible for overall processing of receiving a call signal from the terminal 2 via the ISDN exchange 4 and connecting to the server 7 via the IP network 50. Further, the line control unit 12 performs a process of reconnecting the call that has been temporarily disconnected and moved by the line block processing unit 11 with reference to the connection relation management information 400 (FIG. 6). Further, the line control unit 12 starts the line blocking process by the line blocking processing unit 11 and makes a call to the line whose line status 160 in the line management information 100 (FIG. 3) is “blocking”. In this case, control is performed so that the call is assigned and communicated to a time slot of another line whose line state 160 is “active”.
In addition, the line control unit 12 performs control to transmit a keep alive signal at a predetermined interval from the connection source IP address 402 registered in the connection relationship management information 400 (FIG. 6) to the connection destination IP address 403 ( For details, see FIG. 12 to be described later).

The management information update unit 13 performs a process of updating each information stored in a storage unit (not shown).
For example, the management information update unit 13 uses the use status of each time slot of the TS number 120 of the line management information 100 (FIG. 3) at predetermined time intervals or when any one call disconnection occurs. ("1" or "0") and each information from the used TS number 130 to the energized state 161 is updated.

  The management information update unit 13 calculates the root mean square 150 of the line management information 100 (FIG. 3) based on the remaining TS number 131 and the accumulated energization time 140 using the following (Equation 1).

Here, i is a weighting factor for the remaining TS number 131, and j is a weighting factor for the cumulative energization time 140. However, in this embodiment, i = 1 and j = 1.
Alternatively, the mean square 150 may be calculated using only one of the remaining TS number 131 and the accumulated energization time 140 as a parameter. In this case, “0” may be inserted in either i or j. .

  Also, the management information update unit 13 updates the data reception last time 204, the difference 205 from the current time, and the TS state 206 information of the time slot management information 200 (FIG. 4). Furthermore, the management information updating unit 13 performs processing for deleting information that is not used because there is no re-call from the terminal 2 even after a predetermined time has elapsed in the connection relationship management information 400 (FIG. 6).

Next, processing executed by the network system including the RAS apparatus 1 according to the present embodiment will be specifically described with reference to FIGS.
First, with reference to FIG. 7, a basic call control process in which the terminal 2 makes a call and connects to the server 7 in this network system will be described. Next, the line blocking process of the RAS device 1 will be described with reference to FIG. Next, with reference to FIG. 9 and FIG. 10, processing when the RAS device 1 makes a call from the terminal 2 while the line is being blocked will be described. Then, with reference to FIG. 11 and FIG. 12, a process when a call with a blocked line is called again will be described.

<Connection process between terminal and server>
FIG. 7 is a diagram showing a basic call control sequence when the terminal 2 makes a call and connects to the server 7 in the network system shown in FIG. 1 including the RAS apparatus 1 according to the present embodiment. In FIG. 7, the illustration of the terminal 2 is omitted, and the description will be made as communication from the TA 3 that is connected to the terminal 2 and corresponds to the always-on ISDN communication.

  First, TA 3 makes a call using a special telephone number (hereinafter referred to as “special number”) dedicated to always-on communication, and transmits a “SET UP” signal to ISDN switch 4 (step S101).

Next, the ISDN exchange 4 recognizes that the call is always connected communication based on the “SET UP” signal and the special number included in the signal. Then, the ISDN exchange 4 requests a connection by transmitting a “SET UP” signal to a certain channel of the RAS device 1 serving as a connection interface toward the IP network 50 (see FIG. 1) (step) S102).
Here, the channel means one of the time slots in one line among the T1 interface lines indicated by the T1 interface 5 (# 1 to #N) in FIG. Normally, the TDM data of the primary group speed interface of ISDN is defined in the form of “23B + D” consisting of 23 B channels and one D channel. In this embodiment, since it has N T1 interface lines, it has a time slot of “23B × N + D × N”. Therefore, the RAS device 1 according to the present embodiment has 23 × N channels that can be used for data communication.

  Subsequently, the ISDN exchange 4 returns a “CALL PROC” signal to TA3 (step S103).

  The RAS device 1 transmits a “CONN” signal indicating that connection is possible to the “SET UP” from the ISDN switch 4 to the ISDN switch 4 (step S104), and the “CONN ACK” signal returned by the ISDN switch 4 By receiving the call, the call can be connected (step S105).

  Further, the ISDN exchange 4 transmits a “CONN” signal to the TA 3 (step S106), and notifies that the communication between the TA 3 and the RAS device 1 is possible, and the B channel (Bch) communication between the two is established. The process is started (step S107). The RAS device 1 connects (IP communication) to the server 7 deployed on the IP network 50 in accordance with an instruction from the terminal 2 (step S108).

  By doing so, the terminal 2 (TA3) and the server 7 are connected, and data communication becomes possible. The connection sequence for B channel (Bch) communication and IP communication will be described later with reference to FIG.

<Line block processing>
Next, a description will be given of a process in which the RAS device 1 performs line blocking of the T1 interface 5 (FIG. 1) in the network system in which the always-connected data communication is enabled by the connection process shown in FIG.
FIG. 8 is a flowchart showing the flow of the line blocking process of the RAS device 1 according to this embodiment. Here, an example will be described in which the RAS device 1 acquires the status of each line every predetermined time, updates the information stored in the storage unit, performs line blocking processing, and stops energization of the corresponding line. To do.

First, the line block processing unit 11 of the RAS apparatus 1 scans the rank 151 of the line management information 100 (FIG. 3) every predetermined time. At this time, the line block processing unit 11 defines the variables a and b and sets a = 1 (rank) and b = N (rank) (N = 8 in the example of FIG. 3) as initial values. (Step S10).
In the example shown in the line management information 100 of FIG. 3, the root mean square rank 151 indicates that the 7th line, the 2nd line, the 3rd line, the 8th line, the 8th line from the 1st line to the 8th line. The order is 1 line, 4th line, 5th line, 6th line. Therefore, the first line is the seventh line, and the eighth line is the sixth line.

Next, the line block processing unit 11 changes the line state 160 of the line management information 100 (FIG. 3) from “operating” to “blocking in progress” for the line set at the b-th place in step S10 (step S11). ).
Here, the line blockage processing unit 11 changes the line state 160 of the eighth line, the sixth line, to “in the middle of blockage” (see FIG. 3).

Next, the line blockage processing unit 11 sets the number of TSs remaining in the line with the rank 151 of the line management information 100 (FIG. 3) as vacant (the number of remaining TSs 131) as a variable A, The number of TSs in communication on the b-th line in the management information 100 (number of TSs used 130) is set to the variable B (step S12).
Here, “11”, which is the remaining TS number 131 of the first 7th line, is set in the variable A. Then, “16”, which is the number of used TSs 130 of the eighth line of the sixth line, is set in the variable B.

Subsequently, the line blockage processing unit 11 performs subtraction (AB) on the variables A and B (step S13), and if the value is smaller than 0 (step S13 → No), the process proceeds to step S14. If the value is 0 or more (step S13 → Yes), the process proceeds to step S20.
Here, since variable (A−B) = 11−16 = −5 <0, step S13 → No, and the process proceeds to next step S14.

Next, in steps S14 to S16, the line block processing unit 11 performs a call movement process of moving A of the time slots (TS) in use of the b-th line to the a-th line.
Here, the line block processing unit 11 moves “11” out of “16” time slots (TS) in use of the eighth sixth line to the first seventh line. Performs call movement processing.

Specifically, first, the line blockage processing unit 11 sets the a-th position as the movement destination for each A of the time slots of the b-th line based on the line (call) movement information 300 (FIG. 5). The time slot of the line is determined (step S14).
In this case, the line block processing unit 11 performs the movement of the first 7th position as the destination for each of A (“11”) out of the time slots (“16”) of the 8th sixth line. Determine the time slot for the line. For example, as shown in FIG. 5, the line block processing unit 11 uses the empty time of the time slot number (TS01) of the seventh line as the destination of the time slot in use of the time slot number (TS01) of the sixth line. It is decided to move to the slot, “7/1” is registered in the time slot number (TS01) of the sixth line, and “6/1” is registered in the time slot number (TS01) of the seventh line. Similarly, the time slot of the time slot number (TS02) of the sixth line is set to the time slot number (TS04) of the seventh line, and the 11 time slots in use of the sixth line are changed to the seventh line. Assign to a free time slot.

Subsequently, the line block processing unit 11 uses the time slot management information 200 (FIG. 4) of the b-th line to be moved, and the TS state 206 is “no communication data (communication is performed but data exchange is not performed). No time slot ”is extracted, and the call is disconnected to move the call of the corresponding time slot.
Here, in the example shown in FIG. 4, since the TS state 206 of the time slot “2” of the sixth line is “no communication data”, the line blockage processing unit 11 performs the line (call) movement information 300 (FIG. 5). ), The call is disconnected in order to move the time slot “2” of the sixth line to the time slot “4” of the seventh line.
Then, the line blockage processing unit 11 performs call disconnection for all A when the TS state 206 of the time slot of each of the A calls becomes “no communication data” (step S15). In other words, the line blockage processing unit 11 performs call disconnection for all “11” pieces when all the time slots A (“11” pieces) of the sixth line become “no communication data”.

Next, the line block processing unit 11 adds the connection source telephone number 401, the connection source IP address 402, the connection destination IP address 403, to the connection relation management information 400 (FIG. 6) for the A calls that have been disconnected. Then, a line and a time slot (line / TS 404) to be used when the terminal 2 is called again are registered (step S16).
The line blockage processing unit 11 transmits a keep-alive signal at a predetermined interval from the connection source IP address 402 registered in the connection relationship management information 400 to the connection destination IP address 403 via the line control unit 12. (Refer to FIG. 12 for details).

Subsequently, the line block processing unit 11 sets the subtraction value (B−A) to the variable B as the number of communicating time slots remaining on the b-th line (step S17). Here, 16-11 = 5 is set in the variable B.
Further, the line block processing unit 11 sets (a + 1) to the variable a in order to process the line with the next rank of the a-th rank in which there is no time slot available (step S18). Here, since the time slot of the first line (seventh line) is filled, 1 + 1 = 2 is set to the variable a.

Then, the line block processing unit 11 compares the variable a with the variable b, and if the variable a is equal to or greater than the variable b (step S19 → Yes), the process is terminated. On the other hand, if the variable a is smaller than the variable b (step S19 → No), the line block processing unit 11 returns to step S11 and continues the process.
Here, since variable a = 2 and variable b = 8, variable a is smaller than variable b (step S19 → No), and the process returns to step S11 and continues.
In step S11, if the b-th line has already been changed to "blocking" in the previous routing process, the process proceeds to the next step without performing this process again.

  In step S12 of the next routing process, the line blockage processing unit 11 refers to the line management information 100 (FIG. 3), and sets “23”, which is the remaining TS number 131 of the second highest second line, to the variable A. Set. Then, “5” is set in the variable B as the number of used TSs 130 of the eighth line of the sixth line.

Subsequently, the line blockage processing unit 11 performs subtraction (AB) on the variables A and B (step S13), and if the value is smaller than 0 (step S13 → No), the process proceeds to step S14. If the value is 0 or more (step S13 → Yes), the process proceeds to step S20.
Here, since variable (A−B) = 23−5 = 18 ≧ 0, the process proceeds from step S13 to Yes to the next step S20.

Next, in steps S20 to S22, the line block processing unit 11 performs a call movement process of moving B of the time slots (TS) in use of the b-th line to the a-th line.
Here, the line block processing unit 11 performs a call transfer process of moving the remaining “5” time slots (TS) in use of the eighth sixth line to the second second line.

Specifically, the line blockage processing unit 11 sets the a-th line to be the movement destination for each of B time slots of the b-th line based on the line (call) movement information 300 (see FIG. 5). Is determined (step S20).
Here, the line block processing unit 11 determines the time slot of the second second line as the movement destination for each of the B times ("5") of the time slots of the eighth line of the sixth line. For example, as shown in FIG. 5, the line block processing unit 11 uses the empty time of the time slot number (TS01) of the second line as the destination of the time slot in use of the time slot number (TS16) of the sixth line. It is decided to move to the slot, “2/1” is registered in the time slot number (TS16) of the sixth line, and “6/16” is registered in the time slot number (TS01) of the second line. Similarly, the time slot of the time slot number (TS17) of the sixth line is set to the time slot number (TS02) of the second line, and so on. Assign to two free time slots.

  Subsequently, the line block processing unit 11 sets the TS state 206 to “no communication data (communication in progress) in the time slot management information 200 (FIG. 4) among the b-th (8th) lines to be moved. ”Is not exchanged)”, and the call is disconnected to move the call of the corresponding time slot. Then, when the TS state 206 of each of the B calls becomes “no communication data”, the line blockage processing unit 11 performs call disconnection for all B calls (step S21).

  Next, the line block processing unit 11 adds the connection source telephone number 401, the connection source IP address 402, the connection destination IP address 403, to the connection relation management information 400 (FIG. 6) for the B calls that have been disconnected. In addition, a line and a time slot (line / TS 404) to be used when the terminal 2 is called again are registered (step S22).

Then, the line block processing unit 11 performs a line block process for the b-th line (step S23).
Specifically, the line block processing unit 11 stops energization of the b-th (eighth) line because all the call movement processes for the b-th (eighth) line have been completed. Then, the line block processing unit 11 changes the line state 160 of the line management information 100 (FIG. 3) from “in the middle of blocking” to “blocked” via the management information update unit 13, and sets the energization state 161 to “OFF”. And
Here, the line status 160 of the eighth line of the sixth line is changed to “blocked”, and the energized state 161 is set to “OFF”.

Subsequently, the line block processing unit 11 sets the subtraction value (AB) as the variable A as the number of empty time slots remaining in the a-th line (step S24). Here, 23-5 = 18 is set in the variable A.
Further, the line block processing unit 11 sets (b-1) to the variable b in order to set the line of the next rank after the b-th line subjected to the block process as a processing target (step S25). Here, 8-1 = 7 is set in the variable b.

Then, the line block processing unit 11 compares the variable a with the variable b, and if the variable a is equal to or greater than the variable b (step S19 → Yes), the process is terminated. On the other hand, if the variable a is smaller than the variable b (step S19 → No), the line block processing unit 11 returns to step S11 and continues the process.
Here, since variable a = 2 and variable b = 7, variable a is smaller than variable b (step S19 → No), and the process returns to step S11 and continues.

  In this example, by sequentially executing this processing, it is possible to stop energization of the third line, the sixth line, the fifth line, and the fourth line, and to reduce power consumption.

<Processing when a call is made during blocking>
Next, with reference to FIG. 9 and FIG. 10, a description will be given of line connection processing when a call is made from the terminal 2 while the RAS device 1 is closing the line.
FIG. 9 is a diagram showing a control sequence when a call is made while a line is being blocked in this embodiment.

  First, the ISDN switch 4 receives a call (“SET UP” signal) from the TA 3 (terminal 2) (step S30), and the ISDN switch 4 transfers to the control unit 10 (line control unit 12) of the RAS apparatus 1. A line connection is requested (step S31).

  Subsequently, the line control unit 12 of the RAS apparatus 1 refers to the line management information 100 (FIG. 3) and detects the line state 160 (step S32). Here, it is assumed that the line state 160 is detected as “in the middle of blocking”. Then, the line control unit 12 performs connection destination determination processing for newly determining a time slot of a line in which the line state 160 is “in operation” and the remaining TS number 131 is not “0” (step S33). The connection destination determination process will be described in detail with reference to FIG.

  Next, the line control unit 12 refers to the time slot management information 200 (FIG. 4) for the line and time slot newly determined in the connection destination determination process, and is unique from the corresponding line number 201 and TS number 202. The telephone number 203 is acquired (step S34). For example, if the line number 201 is “1” and the TS number 202 is “3”, the line control unit 12 refers to the time slot management information 200 and sets “00010003” as the unique telephone number 203. To get.

  Then, the line control unit 12 transmits an “INFO” signal including the unique telephone number 203 to the ISDN exchange 4 (step S35), and requests a connection destination change.

  Next, the ISDN exchange 4 requests a line connection (“SET UP”) using the new line number and time slot acquired from the received “INFO” signal (step S36).

  The line control unit 12 of the RAS device 1 refers to the line management information 100 (FIG. 3) and detects the line state 160 (step S37). Here, it is detected that the line state 160 is “in operation”. Then, the line control unit 12 transmits a “CONN” signal to the ISDN switch 4 (step S38), and the ISDN switch 4 transmits a “CONN” signal to the TA 3 (step S39), thereby starting data communication. The

Next, the connection destination determination process in step S33 of FIG. 9 will be described.
FIG. 10 is a flowchart showing a connection destination determination process performed when a call is made while a line is being blocked in this embodiment. In FIG. 10, the processing after the ISDN exchange 4 transmits a “SET UP” signal to the control unit 10 of the RAS apparatus 1 in step S31 of FIG. 9 will be described.

  First, the control unit 10 (line control unit 12) of the RAS apparatus 1 receives a line number (here, “Px”) and a time slot (TS) number (here, “Qx”) from the ISDN exchange 4. Is received (“SET UP” signal) (step S40).

  Next, the line control unit 12 refers to the line management information 100 (FIG. 3), detects the line state 160, and determines whether or not the line “Px” is “in operation” (step S41). If the line status 160 of the line “Px” is “in operation” (step S41 → Yes), the process proceeds to step S47. On the other hand, if the line “Px” is not “in operation” (step S41 → No), that is, if the line state 160 is “in the middle of blocking” or “blocked”, the process proceeds to the next step S42.

  In step S42, the line control unit 12 sets “0” as the initial value of the variable k. Next, the line control unit 12 adds “1” to the variable k (step S43).

  Subsequently, the line control unit 12 selects the line having the line number “Pk” in which the root mean square order 151 of the line management information 100 (FIG. 3) is the k-th place (starting from the first place here) (step S44). ).

Then, the line control unit 12 refers to the line (call) movement information 300 (FIG. 5) and determines whether there is a usable time slot among the time slots of the line with the line number “Pk” ( Step S45). Here, the usable time slot means a time slot that is unused and is not used for the subsequent movement of the time slot, that is, the time slot in the lower part of FIG. 5 is empty.
Then, when there is no usable time slot in the line with the line number “Pk” (step S45 → No), the line control unit 12 returns to step S43 and continues the processing.
On the other hand, when there is a usable time slot (step S45 → Yes), the line control unit 12 proceeds to the next step S46.

In step S46, the line control unit 12 refers to the line (call) movement information 300 (FIG. 5), and selects one of the available time slots of the line with the line number “Pk” as a connection time slot. Determine as.
Then, the line control unit 12 finishes the connection destination determination process, and continues the process after step S34 in FIG.

On the other hand, if the line status 160 of the line “Px” is “in operation” in step S41 (step S41 → Yes), the line control unit 12 determines the time slot of the time slot number “Qx” of the line “Px”. Is determined whether or not can be used (step S47).
If the time slot “Qx” is not usable (step S47 → No), the line control unit 12 proceeds to the processing after step S42.
On the other hand, if the time slot “Qx” can be used (step S47 → Yes), the line control unit 12 transmits a “CONN” signal to the ISDN switch 4 (step S48), and ends the process.

  In this way, even when the RAS apparatus 1 is in the middle of blocking a line and a call is made from the terminal 2, the line with a smaller operation record (the line with the mean square rank 151 being the higher rank line) is smaller. You can select a time slot and connect to the line.

<Processing when a line-blocked call is reissued>
Next, with reference to FIG. 11 and FIG. 12, a description will be given of a line connection process when a call that is disconnected by the line blocking process shown in FIG.
First, with reference to FIG. 11, the connection sequence of the Bch communication in step S107 and the IP communication in step S108 in the call control sequence when the terminal 2 shown in FIG. 7 makes a call and connects to the server 7 will be described. . Next, with reference to FIG. 12, a description will be given of processing for establishing IP communication by omitting IP negotiation when a re-call is made for a call that has been disconnected by the line blocking processing in the present embodiment.

  FIG. 11 is a diagram for explaining a connection sequence of B channel (Bch) communication in step S107 of FIG. 7 and IP communication in step S108.

  First, after the call connection between the TA 3 and the RAS apparatus 1 is established, the RAS apparatus 1 receives the “LCP Conf Request” signal from the TA 3 (step S201), and upon receiving the signal, the LCP negotiation (step S201). S201 to S204) are performed. Then, the LCP (Link Control Protocol: RFC1471) is once terminated, and the user ID is acquired using PAP (Passward Authentication Protocol: RFC1334) or CHAP (Challenge Handshake Authentication Protocol: RFC1994) according to the result (steps S205 and S206). ). Here, a case where CHAP is used is illustrated.

Next, the RAS device 1 performs authentication and negotiation in L2TP (Layer 2 Tunneling Protocol) shown in steps S207 to S216.
First, the RAS device 1 authenticates to a RADIUS (Remote Authentication Dial In User Server: RFC2138) server 8 using the acquired user ID, and acquires tunnel information (steps S207 and S208). Then, the RAS device 1 specifies an LNS (L2TP Network Server) 9 as a connection destination in order to establish an L2TP (RFC2261) tunnel using the acquired tunnel information.

  Subsequently, the RAS device 1 transmits a “SCCRQ” signal that is a control connection establishment request to the specified LNS 9 (step S209), and receives an “SCCRP” signal from the LNS 9 as a control connection establishment response (step S209). S210). Thus, the RAS device 1 transmits a “SCCCN” signal to the LNS 9 as connection establishment (step S211), and receives “ZLB Ack” from the LNS 9 (step S212).

Next, the RAS device 1 transmits an “ICRQ” signal as an incoming call request to the LNS 9 (step S213), and receives an “ICRP” signal as an incoming call response from the LNS 9 (step S214). As a result, the RAS device 1 transmits “ICCN” as an incoming call connection to the LNS 9 (step S215), and receives “ZLB Ack” from the LNS 9 (step S216).
When the authentication / negotiation in L2TP is completed, an L2TP tunnel is established (step S217), and the RAS device 1 transmits “CHAP Success” to TA3. (Step S218). Thereafter, IP communication (data communication) is enabled between TA 3 and LNS 9 through IPCP (Internet Protocol Control Protocol) negotiation.

Next, with reference to FIG. 12, a control sequence in the case where a re-call is made for a call disconnected by the line blocking process will be described.
In FIG. 12, the RAS device 1 (line control unit 12) holds an L2TP tunnel in place of the calling terminal 2 of the call for the call temporarily disconnected due to the line blockage, and the calling terminal 2 It is a figure which shows the control sequence which restarts IP communication when a re-call is made from.

  Here, the RAS apparatus 1 stores connection information regarding a call temporarily disconnected due to a line blockage as connection relation management information 400 (FIG. 6), and keep alive ( (Keep Alive) signal is transmitted to the LNS 9 at a predetermined interval, thereby authenticating the re-call of the calling terminal 2 with the LNS 9 and the RADIUS server 8 and negotiation in L2TP (steps S207 to S216 in FIG. 11). By omitting, IP communication can be resumed. This will be specifically described below.

  First, the line control unit 12 of the RAS device 1 transmits a keep alive signal to the LNS 9 at a predetermined interval in order to keep the L2TP tunnel (step S301). Note that this process ends if there is no call from the terminal 2 when a predetermined time has elapsed.

Then, when a re-call is made from the terminal 2 within a predetermined time during which the line control unit 12 of the RAS device 1 is transmitting a keep-alive signal to the LNS 9, a diagram is sent between the TA 3 and the RAS device 1. IP communication is resumed only by performing the same processing as in steps S201 to S206 shown in FIG. 11 (the description is omitted because it is the same as that in FIG. 11) (step S302).
That is, IP communication can be established without performing any authentication / negotiation in L2TP (steps S207 to S216 in FIG. 11) between the RAS apparatus 1 and the RADIUS server 8 and LNS9.

  As described above, according to the RAS apparatus 1 and the line blocking method according to the present embodiment, among the N T1 interface 5 lines, a call with a line with a large data communication operation record is used as a line with a small operation record. When all calls have been moved, the power supply to the line can be stopped. Therefore, in data communication using a primary group speed interface that accommodates a plurality of subscribers by physically multiplexing a single line, energization of a line with a larger operation record is stopped, thereby reducing power consumption. Longer service life can be realized.

  Note that the RAS device 1 according to the present embodiment can execute processing also in the following cases.

(Case A)
In the example shown in the present embodiment, one line is in the middle of blocking, 6 of the other lines use all 23 time slots, and the remaining 1 of the other lines is r. If you use multiple time slots.
In such a case, only (23-r) usable time slots remain, and connection becomes impossible when more call connections occur. Therefore, the RAS apparatus 1 sets a threshold value m1 regarding the number of time slots, and as a determination accompanying step S45 in FIG. 10, when r exceeds the threshold value m1, the line status 160 of the line management information 100 (FIG. 3). Is changed to “in operation”, and if a call connection request is generated for the line, a process for permitting call connection to the line is performed.

(Case B)
In the example shown in the present embodiment, some lines are blocked, some other lines are in operation, and all the 23 times except for one line are in operation. A slot is used and only one of its lines uses s time slots.
Even in such a case, the RAS device 1 sets the threshold value m2 regarding the number of time slots, and as described above, when s exceeds the threshold value m2 as the determination accompanying step S45 in FIG. Among the lines in which the line state 160 of the information 100 (FIG. 3) is “blocked”, energization of the line corresponding to the highest rank is started in the rank 151 so that a new call connection can be accepted.

  The RAS device 1 according to the present embodiment can also be implemented in the following modifications.

(Modification 1)
The specific telephone number 203 of the time slot management information 200 (FIG. 4) in the present embodiment is premised on prior registration. However, when the time slot management information 200 is created, based on the line number information, time slot (TS) number information, and connection destination telephone number included in the “SET UP” signal transmitted from the ISDN exchange 4, The connection destination telephone number may be stored in the unique telephone number 203 of the time slot management information 200 corresponding to the line number and the time slot (TS) number.

(Modification 2)
In the TS state 206 of the time slot management information 200 (FIG. 5) in the present embodiment, the determination of which state belongs is performed by measuring time as indicated by the difference 205 between the data reception last time 204 and the current time. . However, regardless of such time measurement, the data communication amount is measured, a certain threshold u is set in advance, and if the data communication amount is smaller than the threshold u during a unit time, “communication data” It may be “None”.

(Modification 3)
In the present embodiment, the process of moving to a time slot of another line and the process of stopping power supply to the line are executed every predetermined time. This process is executed when a call disconnection occurs. May be. In that case, memorize the number of lines and time slots (TS) in use, confirm that there is a call disconnection and that there are enough time slots (TS) to block one or more lines. Then, when it is determined that the line can be blocked, the call moving process may be executed.

(Modification 4)
In the present embodiment, as shown in FIG. 9, when the line is in the process of being blocked, an example of switching to connection to another channel using the “INFO” signal has been shown. However, when the ISDN switch 4 requests a call connection to a line that is in the process of being blocked, the ISDN switch 4 can send another signal that rejects other connections instead of the “INFO” signal, or can make another response to the ISDN switch 4. The channel may be requested to reconnect.

1 RAS device 2 Terminal 3 TA
4 ISDN switch 5 T1 interface (primary group speed interface)
6 IP interface 7 Server 10 Control unit 11 Line block processing unit 12 Line control unit 13 Management information update unit 20 T1 interface unit 30 IP interface unit 40 Telephone network 50 IP network 100 Line management information 200 Time slot management information 300 Line (call) Movement information 400 Connection management information

Claims (6)

IP packets connected to the ISDN switch through a plurality of lines of the primary group speed interface, connected to the IP network through the IP interface, and received and transmitted from the ISDN switch and TDM (Time Division Multiplexing) data in the IP network RAS (Remote Access Service) device for mutual call conversion and call connection,
A storage unit for storing line management information for storing a use state and energization time of a time slot for each of a plurality of lines of the primary group speed interface;
Based on the use state of the time slot and the energization time or any one of them, the operation result of each line of the primary group speed interface is calculated, the call of the line having the large calculated operation result is disconnected, and the call is disconnected A control unit that moves a call to a line with a small operation record and performs line blocking processing to stop energization of the line with a large operation record;
RAS apparatus characterized by comprising. The control unit of the RAS device is
When disconnecting a call of a line with a large operation record, determine a time slot of the line with a small operation record as a destination,
The connection source and connection destination address information that the call was connected to before disconnecting, the transfer destination line and the determined time slot are stored in the storage unit as connection relationship management information,
When there is a re-call request for the disconnected call from the ISDN switch, the connection relation management information is referred to, the address information is acquired, and the destination line and the determined time slot are used. The RAS apparatus according to claim 1, wherein reconnection is performed. The control unit of the RAS device is
When there is a call request from the ISDN switch to the line that is being blocked, the ISDN switch is notified of an unused time slot of a line with a small operation record. The RAS apparatus according to claim 1, wherein connection is performed. The control unit of the RAS device is
Blocking in which all time slots of each of the other lines except one line are in use among the plurality of lines of the primary group speed interface, and the one line is performing the line blocking process If the number of time slots in use for the one line exceeds a predetermined threshold when the line is in the middle, the line block processing for the one line is stopped and a call connection is made. The RAS apparatus according to claim 1 or 2, wherein the RAS apparatus is characterized. The control unit of the RAS device is
Several lines of the plurality of lines of the primary group speed interface are in a blocked state in which energization to the lines is stopped, and one line is excluded from the lines other than the several lines. When all the time slots of each of the other lines are in use, when the number of time slots in use of the one line exceeds a predetermined threshold, among the several lines in the blocked state, The RAS apparatus according to claim 1 or 2, wherein energization to a line having the smallest operation record is started and call connection is performed. It is connected to the ISDN switch through a plurality of lines of the primary group speed interface, and is connected to the IP network through the IP interface, and mutually converts TDM data received from the ISDN switch and IP packets transmitted and received through the IP network. A line blocking method of a RAS device for call connection,
The RAS device is
A storage unit for storing line management information for storing a use state and energization time of a time slot for each of a plurality of lines of the primary group speed interface;
Based on the use state of the time slot and the energization time or any one of them, the operation result of each line of the primary group speed interface is calculated, the call of the line having the large calculated operation result is disconnected, and the call is disconnected A line blocking method comprising: moving a call to a line with a small operation record, and executing line blocking processing for stopping energization of the line with a large operation record.

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