JP2977088B2 - ISDN communication device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to ISDN communication devices, and more particularly to integrated services digital networks (ISDs).
N: Integrated Services Digital Network)-BRI (Basi
c Rate Interface) and ISDN-PRI (Primary Rate Inte
rface) as a communication device. For example, G4 facsimile, facsimile mail system, ISDN telephone, ISDN answering machine, computer terminal, PBX (Private Branch Exchange), personal computer
It is applied to a LAN (Local Area Network) connection selection technology.

Conventional technology In recent years, ISDN (Integrated Services Digital Network)
, And data terminal devices for exchanging data using this ISDN are gradually being put to practical use.

This ISDN will replace the conventional PSTN (Public Telephone Network) in the future, but both will be used until the replacement is completely completed.
Also, in this case, mutual entry of ISDN and PSTN is considered, and a data terminal device connected to ISDN and a PSTN are considered.
Can exchange data with the same type of data terminal device connected to.

By the way, when a data terminal device is connected to an open public network such as ISDN or PSTN, it may be damaged in response to an unnecessary incoming call.

For example, a telephone may be bothered or annoyed by a prank call or an unnecessary sales call, or an unnecessary direct mail or frustrated image may be sent to a facsimile machine. In some cases, inconveniences such as wasted resources may occur.

On the other hand, in ISDN, the call setting message received by the receiving terminal at the time of receiving a call includes a calling number information element representing the telephone number of the calling terminal. It is possible to limit the partner terminal that responds.

That is, all the calling numbers of the partner terminals that respond to the incoming call are registered in advance, and when a call setting message having an unregistered calling number is received, the incoming call is ignored.

However, in such a conventional method, since the calling numbers of all the partner terminals that respond to the incoming call are registered, if the number of partner terminals increases, the registration work becomes inconvenient. Also, if the number of calling numbers to be registered increases,
As a result, the risk of misregistration of the calling number increases, which may cause a problem of responding to an incoming call from the misregistered destination. Further, when the calling number of the partner terminal is changed, there is a disadvantage that the work of updating is required.

To solve these problems, see, for example,
-78353 is proposed. The control method of the ISDN terminal device proposed in this publication realizes a selective reception mode in which a destination terminal that responds to an incoming call is limited by a calling subaddress included in a call setting message.

On the other hand, in the case of an analog telephone, a device for selecting a calling party inserted between a line and a telephone has been commercialized. In response to the incoming call from the analog telephone line, the device automatically receives the incoming call, responds to the response message by voice, and then requests the caller for a password using a touch-tone tone. Only when this password matches the one registered in advance, the ringing bell of the analog telephone rings and the incoming call is displayed. This is the case for analog telephones and has not been proposed in ISDN.

Since the service of ISDN was started in April 1988, its use has not been sufficiently studied.
In addition, although data communication such as a connection gateway between LANs and communication between computers are advantageous in terms of cost, they do not have sufficient functions for security measures. There are also ways to keep your ISDN subscriber number private so that it can be protected from hackers, but the private method is not permanent. In addition, when used as a telephone, data such as call charges and time is sent from the network at the end of a call, so services such as displaying the data to the user can be performed. There is no ability to provide freedom. In addition, a protocol for defining ISDN access for a function of selecting a response to an incoming call has not been sufficiently studied. If the receiving device does not answer, the ringing tone will continue to ring forever, but during this time the line will be occupied and the inconvenience that it cannot be used by other callers or by itself will occur. In addition, the ringing sound and any ringing display itself are unpleasant. A digital high-performance telephone is required to have a function capable of selecting an advanced incoming call.

Also, if a large number of ISDN-compatible G4 facsimile machines that can transmit at least 6 times faster than G3 facsimile machines will be installed, direct mail or flyers will be sent to unspecified large numbers of parties, such as G4 facsimile machines on the receiving side. There is also a problem that the information may be sent ignoring the wishes of the installation manager or owner.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and has an ISDN communication device for securing a degree of freedom in responding to an incoming call and for solving problems such as protection from mischief represented by a hacker. The purpose of this is to provide.

Configuration In order to achieve the above object, the present invention provides an ISDN board connected to an ISDN line and executing a layer 1, layer 2, and layer 3 communication procedure to a personal computer (PC).
The ISDN communication device connected to
Call control primitives mounted on the ISDN board, referring to the requested data, performing line connection, response, call control means for executing a predetermined connection restriction processing such as disconnection, connected to the PC, the initial of the ISDN board A first table for storing an operation program and for registering a destination calling number for which the ISDN board rejects a response to an incoming call; and a destination table for allowing the ISDN board to respond to an incoming call. External storage means for storing a second table to be registered; number recognizing means for recognizing a calling party number from a calling number information element of a call setting message of an incoming call; and a counterpart call from the first and second tables A number search means for reading a number and comparing it with the caller number recognized by the number recognition means; and a connection restriction processing of the call control means for the incoming call based on a search result of the number search means. Select the call control means is obtained by means executes a process of sending the calling party addressed a message indicating a communication rejection in performing the connection restriction process of line disconnection. Hereinafter, a description will be given based on examples of the present invention.

First, the position of the present invention in the integrated service digital network (ISDN) procedure will be described.

For the specific operation of the service interface when communicating according to the ISDN procedure and the communication procedure performed by the ISDN communication device, see, for example, “INS Network Service Interfaces 1, 2 and 3” (NTT Edition).
1989.6. Published by the Telecommunications Association).

FIG. 3 is an overall configuration diagram of the ISDN communication device, in which 31 is a call control unit (CC), 32 is a resource management unit,
33 is a layer 3 protocol control unit, 34 is layer 2, layer 1, and 35 is a network. The layer function in the figure has a layer 1 function for making an electrical connection between terminals via a physical communication path (metallic, optical cable) and a transmission procedure for correctly transmitting and receiving information between terminals. It is composed of a Layer 2 function and a Layer 3 function for controlling and managing network connections such as setting and release of a communication path to a requested communication partner, interpretation of service contents, and test of a communication path. The present invention relates to the call control unit 31 shown in FIG. 3, and is positioned in call control (call control) such as connection, response, and disconnection of ISDN.
It should be noted that the layer 3 protocol control unit 33 uses the SDL (Specificati
on and Dcscription Language) block.

FIG. 4 is a diagram showing a process of the call control unit in FIG. 3, and is an explanatory diagram of an SDL diagram of a terminating connection and a connection of ISDN layer 3 protocol control according to the present invention.

FIG. 5 illustrates the description method (user side) of the SDL diagram in FIG.

In FIG. 4, when the third call setting display from the upper left is requested as a primitive to the call control unit (CC), the incoming call selection response communication partner registration table and the incoming response selection rejection communication partner registration table of the present invention exist. The reference data area to be referred to is determined by referring to the call control unit 31 including the search / collating means for searching and collating the number digit and the communication partner number and the determination means for performing the predetermined connection restriction determination. Case) Thereafter, in cooperation with the resource management unit 32, the attribute determination is performed between the partner device that makes the connection request and the own device, and the layer 3 protocol control unit is finally allowed to accept the incoming request or reject the incoming request as a primitive.
Take the series of steps required to 33.

In the call setting display of FIG. 4, the call control unit searches and compares the number digit with the communication partner number registered in advance, and sends a “call request” of A or a “rejection request” of B to the primitive. Do. That is, in the case of a selective response in the incoming call in the figure, the line under communication is executed from the call request of the line A, and in the case of a selective response rejection in the incoming call, an empty line is rejected from the rejection request of the line B. Execute the line.

FIG. 1 and FIG. 2 are configuration diagrams for explaining one embodiment of the ISDN communication apparatus of the present invention.
Fig. 2 is an overall configuration diagram of the ISDN communication device.
FIG. 2 is a configuration diagram of a PC (personal computer) main body and an ISDN board. In the figure, 1 is an ISDN board mounted on a PC, 2 is a PC
Main unit, 3 speaker, 4 telephone handset, 5 digital service unit (DSU), 6 ISDN-PBX or network, 7 display, 8 keyboard, 11 stack, 12 PC application, 13 Is the ISDN board driver in the PC body, 14 is the external storage device (DISK),
15 is a system bus (memory interface), 16 is a reference data area, 17 is a connection status table,
18 is a channel table, 19 is a connection control table, 20 is a function instruction flag and a registration table, 21 is a call control unit, 22 is a layer 3 protocol control unit, and 23 is a layer 2
Protocol control unit, 24 is a layer 1 protocol control unit, 25
Is a primitive buffer storage area, and 26 is a buffer.

According to the present invention, a device having a communication procedure execution function of layers 1, 2, and 3, ie, an ISDN board 1 is mounted by a method of connecting the system bus of a personal computer PC to the ISDN board 1 for transmitting and receiving a call. The telephone 4 is connected, and further connected to a DSU (Digital Service Unit) 5, which is an interface on the ISDN network side.

The program and the reference data and the primitive buffer in FIG. 2 are arranged in an address structure, and the program having the address structure is stored in an external storage device (DIS) in the PC main body.
K) is stored in 14 and the specified P
Performs the initial operation of the C main body, then performs the initial operation of the ISDN board, and transfers (LOADING) from the external storage device 14 to the ISDN board by a predetermined method. Executed after initializing the process. Here, the search / matching means for searching / matching the incoming call selection / response communication partner registration table, the incoming call response / selection rejection communication partner registration table, the number digit and the communication partner number of the present invention, and the judgment means for making a predetermined connection restriction judgment are provided by another program. Along with other programs to the ISDN board via the system bus 15 at the time of initialization (loading: LOADIN
G) Being run on an ISDN board. However, the procedure from the temporary storage to the external storage device of the PC main body until the loading is shown in the embodiment. Other methods, for example, storing the program in the read-only memory (ROM) of the ISDN board and storing the program in the registration table Needless to say, a method of loading and executing only the function instruction flag can be considered.

FIG. 6 shows an example of changing the contents of the reference data area on the ISDN board side from the PC main body. First, there are the application functions of the PC itself such as addition, change, and deletion operations and rewriting of the function instruction plug. After these operations, the PC
In the external storage device (DISK). Next, a transfer instruction is issued to the ISDN board, and stored in the reference data area on the ISDN board side.

In the start of the present invention, the call setting display in FIG. 4 is copied from the layer 3 protocol control unit 22 in FIG. The call control unit 21 executes processing of the present invention, which will be described later, and returns the result to the layer 3 protocol control unit 22 in the form of a primitive request. If the content of the primitive request determines that the processing of the present invention does not limit the connection and if the contents of other information elements such as low-layer compatibility and high-layer compatibility are permitted, the call state number in FIG. The process proceeds to the process A of a certain 6 incoming call, 7 calling, 8 response, 10 communicating, and the connection process starts to be "communicating".

If the determining means for performing the predetermined connection restriction determination of the present invention determines that the connection is restricted, the process proceeds to the processing of the call state number 6 in FIG. .

The lower layer function is for setting a communication path between the calling terminal and the destination terminal in the ISDN service and for correctly transmitting information to the partner terminal, and the circuit switching function and the packet switching function correspond to this. In addition, the higher layer function is based on the OSI hierarchical model (Model for Open Systems Intercon
nection) layer, and has functions such as communication procedures between terminals, storage and conversion of information, and a communication processing function in a network. The teleservice will be realized by combining the lower layer function and the higher layer function. In ordinary telephone and facsimile,
Through the communication path set by the lower layer function,
Communication is performed by the higher layer function of each terminal. In this case, the network is not involved in higher layers. On the other hand, in the facsimile communication network service, a facsimile storage / conversion function is provided in the network, and communication between terminals is performed through the function. In this case, the network is involved in both the lower and higher layers. .

The high-layer function is not necessarily required for ISDN like the low-layer function, and it is considered that the communication processing or information processing center outside the ISDN or the terminal itself often has the function.

In the reference data area of the ISDN board,
Two reference tables such as selective incoming call and incoming call rejection as shown in the configuration example of (b) are provided, and the subscriber number of the communication device to which connection is permitted is stored in the incoming call selection response communication partner registration table and the communication device of the communication device whose connection is to be rejected. The subscriber number is registered in the incoming call response selection rejection communication partner registration table in advance. In this example, two sets of subscriber numbers “727-3463” and “872-3364” are registered in hexadecimal code in the table area indicated by the incoming call selection response communication partner registration table name. The hexadecimal "A" code is used to display the registered subscriber number. The end of the registration table ends with EOP (End of File). Similarly, “03-593-3411” and “3743” are registered in hexadecimal code in the table area indicated by the incoming call response selection rejection communication partner registration table name. Here, the following four types of methods for matching the number of the registration table with the number digit can be considered.

It detects that the number digit and a set of registered subscriber numbers completely match.

It detects that the number specified by the system from the first number of the set of the number digit and the registered subscriber number or the number equal to or less than the number of the number digit partially matches from the beginning.

It is detected that the number specified by the system from the last number of the set of the number digit and the registered subscriber number or the number less than the number of the number digit partially matches from the end.

It is detected that the number specified by the system or the number equal to or less than the number of the number digits partially matches from the number at an arbitrary position in the pair of the number digit and the registered subscriber number.

Further, in FIG. 7 (c), the function instruction flag is provided in the reference data area in the same manner as "executing", "match" and "error" indications are allocated by 1 bit.

Here, the function instruction flag is composed of one byte in the storage means and has two functions. That is, it has information indicating whether to search the table. By rewriting with a keyboard or the like, an instruction to answer an incoming call without performing search / collation or an instruction to reject communication is issued. The instruction information such as the primary stop of the selective call receiving function of the present invention is held.

The result of the search and collation is temporarily stored, and the value of the display type of the communication refusal is determined.

FIG. 8 is a diagram showing a flowchart of the search collation processing, and the above-mentioned method is used for a method of matching with a number digit. Hereinafter, the steps will be sequentially described.

step1: First, the calling number content length, the display identifier, and the network verification identifier of the calling number information element are read. Note that the calling number information element is shown in FIG. The calling number information element is used to identify the originator of the call, and is coded. For the display identifier, bit “00” can be displayed, “0”
“1” cannot be displayed, “10” can be identified by the number that can be displayed according to the interconnection conditions, “11” is reserved,
In the network interface, the display identifier is used to indicate the calling user's intention to display the calling number to the called user. If the display identification is “01” or “10” at the called user's network interface, the number digit is not notified.

Further, the network verification identifier can be identified by the bit “00” being reserved, “01” being user input, network verification, success, “10” being reserved, “11” being network input, and It is ignored and the transfer of the calling number to the called user is performed only in the case of “01” and “11”.

step 2: It is determined whether the display identifier is "01", that is, whether display is not possible, whether a number digit exists, and whether the network verification identifier is "11".

step3: If YES in step2, the number digit (IA5 code: code for setting the ISDN number, one byte is one dial) is converted to a hexadecimal code.

step4: Reset the internal counter.

step5: The index pointer points to EOP (End
of File).

step6: If not EOF, search for a delimiter code "A" in the table pointed to by the index pointer and the internal counter.

step7: Add an internal counter.

step8: Determine whether the segment search is successful.

step9: If not successful, return to step5. If there is success, the registration table is reversely read according to the value of the internal counter, and the number is searched.

step10: Determine whether the number digit matches (or partially matches).

step11: If matched, set "match" of the function instruction flag to 1
To end.

step12: If they do not match, add the index pointer.

step13: Reset the internal counter and return to step5.

step14: If NO in step2, determine whether the "identification" bit of the function instruction flag is "0".

step15: If "0", set the "error" bit of the function instruction flag to 1.

step16: Copy the display identifier and the network verification identifier to the logging area.

FIG. 10 is a flow chart for explaining a judgment means for making a predetermined connection restriction judgment of the present invention. Hereinafter, the steps will be sequentially described.

step1: First, the executing bit of the function instruction flag is set to “1”, and the match bit of the function instruction flag is set to “0”.

step2: Determine whether the response bit of the function instruction flag is "0". If not “0”, go to step 8 described later.

step3: If "0", set the index address of the incoming call selection response communication partner registration table name to the index pointer.

step 4: Perform the search / collation processing shown in FIG. 8 step 5: Next, it is determined whether or not the error bit of the function instruction flag is "1".

step6: If the error bit is "1", the number digit has not been set, so the reason display (reason type value) is set, and the procedure goes to step 14 described later.

step7: If the error bit is not "1", it is determined whether the match bit of the function instruction flag is "1". If the match bit is “1”, the response is a selection response, so the flow proceeds to step 14 described later.

step8: If the match bit is not "1", it is determined whether the reject bit of the function instruction flag is "0". Also step2
If the response bit of the function instruction flag is not "0", it is similarly determined whether or not the rejection bit is "0".

step9: If the reject bit is "0", set the index address of the incoming call response selection rejection communication partner registration table name to the index pointer. If the reject bit is not "0", the procedure goes to step 11 described later.

step10: Next, the search and collation processing shown in FIG. 8 is performed.

step11: If the rejection bit is not "0" in step 8, it is determined whether the identification bit of the function indication flag is "0". If the identification bit is "0", go to step 10. If the identification bit is not "0", the flow proceeds to step 14 described later.

Step 12: After performing the registration and collation processing in step 10, it is determined whether both the match bit and the error bit of the function instruction flag are not “0”.

step13: If both the match bit and the error bit are not “0”, a reason display (reason type value) is set, and the process proceeds to the next step.

step14: If both the match bit and the error bit are "0", the error set of the function instruction flag is set to "0", and the executing bit of the function instruction flag is set to "0".

FIG. 11 is a diagram showing a result of the judgment of the predetermined connection restriction process. In the figure, the response bit refers to the incoming call selection response communication partner table, and the reject bit refers to the incoming response selection rejection communication partner table. The identification bit is limited by 0/1.

As can be understood from FIGS. 10 and 11, the search and collation of the incoming response selection rejection communication partner registration table are performed prior to the search and collation of the incoming response selection rejection communication partner registration table. It should be noted that there are a fixed process in which the response bit, the rejection bit, and the identification bit in FIG. 11 are all "0", and a fixed process, and other processes. Also, as shown in FIG. 7 (C), each bit is assigned to the identification of the response selection response and the rejection of the response selection of the function instruction flag in the function instruction flag. It goes without saying that each data in the reference data area can be arbitrarily changed by the main body application of the PC as shown in FIG.

FIG. 12 is a diagram for explaining the flow of layer 3 messages in the ISDN layer 3 standard (normal) sequence and the operation of the communication device of the present invention.

Here, a basic data transmission procedure performed by an ISDN terminal device such as the G4 facsimile device will be described.

The calling terminal first sends a call setup message SETUPA to ISDN to request a call setup with the called terminal, and the ISDN sends a call setup message SETUPB to the designated called terminal to request call setup. ISDN sends a call setting acceptance message CALL_PROC for notifying the call setting status to the calling terminal.

When the called terminal detects an incoming call, the call message ARER is sent to ISDN.
T sends IS and the ISDN sends a call message ARERT to the calling terminal to notify that calling of the called terminal has started.

When the called terminal answers the incoming call, the response message CONN is sent to ISDN.
ISDN sends a response message CONN to the calling terminal to notify that the called terminal has accepted the call.

Also, ISDN sends a response confirmation message CONN_ACK to the called terminal.
To confirm the response of the called terminal, at which point an information channel for data transmission is established between the calling terminal and the called terminal.

Thus, data transmission between the calling terminal and the called terminal is performed according to the transmission control procedure set for each transmission function. For example, in a G4 facsimile apparatus, data transmission is performed based on a G4 facsimile transmission control procedure.

When the data transmission is completed, the originating terminal sends a disconnection message DISC to the ISDN to request release of the information channel, and the ISDN sends a disconnection message DISC to the destination terminal to notify the destination of the restoration of the information channel.

As a result, when the destination terminal responds to the ISDN with a release message REL for notifying the completion of the channel disconnection, the release message REL is transmitted from the ISDN to the calling terminal. When the channel release is completed, the calling terminal issues a release completion message REL_COMP to the ISDN.
To notify that fact, ISDN sends a release completion message REL_COMP to the destination terminal, the release of the information channel is established, and the information channel set between the calling terminal and the destination terminal Is completely released.

In this way, an information channel is set between the calling terminal and the called terminal, data transmission is performed, and the information channel is released.

In the embodiment of the present invention, a call setup request message (SETUPA) is transmitted to the network to make a call setup request from the calling communication device to the called communication device. In (SETUPA), the display identifier of the calling number information element is "00", indicating that display is possible. In the called exchange of the network, SETUPB is transmitted to make a call setting request to the called communication device. In SETUPB, the calling number information element has a calling number content length of 9 octets, and the network verification identification is "11", indicating that the network is activated. The number digit is, for example, “83092
20 ". That is, when SETUPB is transmitted,
The processing is started from the empty call state shown in FIG. 4, and in the case of a selective response in the incoming call state, processing of the A line is performed, and in the case of rejection of the selective response, processing of the B line is performed. A and B in FIG. 4 correspond to A and B in FIG.
In the figure, the call setting is accepted by a solid line A in the case of a selection response, and is released by a dotted line B in the case of a selection response rejection. Each processing of layer 1 and layer 2 receiving SETUPB from the network is transmitted to the layer 3 protocol control unit as a layer 3 message. It is specified that the calling number information element included in SETUPB conforms to the format shown in FIG. As a result, the copied number digit data, which is the subscriber number of the caller, can be recognized.

The layer 3 protocol control unit 33 in FIG. 3 requests a call setting display primitive from the layer 3 message call control unit 31, and the call control unit 31 processes the primitive by a revised program, as shown in FIG. The pre-registered communication partner number can be searched and compared with the duplicated number digit which is the subscriber number of the recognized caller. This search / collation processing refers to the registration table corresponding to the bits corresponding to the “reject” and “response” of the function instruction flag in FIG. These “reject” and “response” bits are rewritten by the application of the PC main unit shown in FIG.
Alternatively, it can be changed with a dip switch mounted on the ISDN board. Needless to say, the reference to the registration table corresponding to the corresponding bit is executed / skipped when the value is changed. Note that all or part of the registered subscriber number group is collated by system data (not shown), but the incoming call selection response communication partner registration table allows a connection request from a calling communication device whose number matches. If the numbers do not match, a request is sent from the called exchange (network) to transmit a layer 3 disconnection (DISCONNECT) message including a communication refusal in the cause indication to the calling communication device. The rejection of the call can be recognized, and, for example, a display such as "Aitechak Shinkyohi" can be displayed. Step in FIG.
CAUSE is CALL_REJ shown in 6 and step13). Similarly, the incoming call response selection rejection communication partner registration table is referred to for rejecting a connection request from a calling communication device having a matching number. When the reference is made and the numbers match, the processing for disconnection (DISCON
NECT) Requests the called exchange (network) to transmit the message to the calling communication device. In the order of reference, reference to the incoming call selection response communication partner registration table has priority.

Also, if the calling communication device transmits SETUPA to the network in response to a request not notifying its subscriber number, for example, manually, or in the case of a connection call (audio service call) from a conventional subscriber telephone, SETU in Fig. 12
Since the display identifier of the calling number information element of the PB is displayed as "01", if this part is preferentially recognized, connection restriction can be efficiently performed without executing invalid number digit recognition.

Effects As is clear from the above description, the present invention has the following effects.

(1) Accept a call setting request from a specific communication partner number (selection response) or reject a call setting request from a specific communication partner number (selection rejection), and useless ring tone and display on the communication device Without causing
And an advanced security function is obtained.

(2) In the communication device requesting the call,
It is possible to know the reason for the connection rejection, to prevent the network from generating another invalid call again, and to make effective use of network resources.

(3) The possibility of misrecognizing the subscriber number of the calling communication device hidden (SCREENING) by the network can be prevented.

(4) When a communication party number that allows a call setup request from a specific communication party number (call selection response) or rejects a call setup request from a specific communication party number (call answer selection rejection) is registered to some extent Therefore, the flexibility of easily and temporarily stopping functions without adding or deleting numbers is increased.

(5) Incoming calls from non-ISDN phones such as general subscriber phones are acceptable.

(6) The storage area of the ISDN board can be saved, cost can be reduced, and minimum security can be ensured.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram for explaining an embodiment of a communication device according to the present invention, FIG. 2 is a configuration diagram of a PC main body and an ISDN board of the communication device according to the present invention, and FIG. FIG. 4 is a diagram showing the processing of the call control unit in FIG. 3, FIG. 5 is a diagram showing the description method (user side) of the SDL diagram in FIG. 4, and FIG. FIG. 7 is a diagram showing an example of changing the contents of the reference data area on the ISDN board side from the PC main body, FIG. 7 is a diagram showing an example of the reference data structure, FIG. FIG. 10 is a diagram showing a calling number information element. FIG. 10 is a flowchart of a connection restriction process.
FIG. 11 is a diagram showing a judgment result of a predetermined connection restriction process, and FIG.
The figure is a diagram for explaining the flow of messages in the ISDN layer 3 standard (normal) sequence and the operation of the communication device of the present invention. 1 ... ISDN board mounted on PC 2 ... PC body 3 ...
Speaker, 4 telephone handset, 5 digital service unit (DSU), 6 ISDN-PBX or network, 7 display, 8 keyboard, 11
... Stack, 12 PC application, 13 PC
ISDN board driver in the main unit, 14 External storage device (DISK), 15 System bus (memory interface), 16 Reference data area, 17 Connection status table, 18 Channel table, 19 Connection control table, 20: Function instruction flag and registration table, 21: Call control unit, 22: Layer 3 protocol control unit, 23: Layer 2 protocol control unit, 24 ...
... Layer 1 protocol control unit 25... Primitive buffer storage area.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04M 1/66 H04M 1/00 H04M 11/00-11/10

Claims (1)

(57) [Claims] 1. An ISDN communication apparatus which is connected to an ISDN line and executes a layer 1, layer 2, and layer 3 communication procedure to a personal computer (PC). With reference to the primitive requested data, connection of the line, response, call control means for executing a predetermined connection limiting processing such as disconnection, and connected to the PC, storing an initial operation program of the ISDN board, A first table in which an ISDN board registers a destination calling number that rejects a response to an incoming call, and a second table in which the ISDN board registers a destination calling number that allows a response to an incoming call. External storage means for storing; a number recognizing means for recognizing a calling number from a calling number information element of a call setting message of an incoming call; A number searching means for reading out a calling number and comparing the number with the calling number recognized by the number recognizing means; and a connection restriction process of the call control means for the incoming call based on a search result of the number searching means. An ISDN communication apparatus for performing a process of selecting and transmitting a message indicating a communication rejection to a caller when the call control means performs a connection restriction process of disconnecting a line.