JP3310339B2 - ISDN terminal equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ISDN terminals, and more particularly to ISDN terminals using non-automatic TEI allocation.

[0002]

2. Description of the Related Art Conventionally, an integrated service digital network (ISD)
N: An ISDN terminal device connected to an Integrated Services Digital Network and performing digital communication with each other is frequently used. Various signals are exchanged between the ISDN user and the network to set up and release communication, and are defined as a protocol between the user and the network. This ISDN user-network protocol is based on OSI
(Open system interconnection) The layers are divided into layers 1 to 3 based on the reference model. Above all, Layer 2
Is known as the D-channel link access procedure (LAP
D: Link Access Procedure on the D-channel), and has a function of transmitting information between the user and the network in units of frames to perform highly reliable signal transfer by overcoming transmission errors and the like.

[0003] In the basic interface, in order to guarantee portability such that a certain terminal device (TE) can be used anywhere, each terminal device has a terminal termination point identifier (T).
An EI (Terminal Endpoint Identifier) is assigned. In other words, this TEI value is not registered in the network in advance, but is assigned according to a predetermined procedure when necessary.

[0004] There are automatic TEI allocation and non-automatic TEI allocation in this TEI value allocation, and the TEI value of the automatic TEI allocation given by the network based on the request of the terminal device is 64 to 12
6, and the TEI value of the non-automatic TEI assignment is assigned in the range of 0 to 63. And non-automatic TEI
The allocation is used when the terminal itself is set in advance by a DIP switch or ROM, and unlike the automatic TEI allocation, the terminal device does not issue a TEI allocation request to the network.

[0005] As described above, in the conventional ISDN terminal device that performs non-automatic TEI allocation, the user is responsible for all the TEI values to be used, and the terminal device uses the TEI value.
The processing when detecting multiple assignment of values or after the network releases the TEI value has merely been to notify the user that the TEI value has been released.

[0006]

As described above, in the conventional ISDN terminal device, the processing in the case where the TEI value is released merely stops the notification to the user that the TEI value has been released. When a condition for canceling the TEI value occurs, there is a problem in that the user cannot perform a calling / calling operation until the user sets a new TEI value.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. In an ISDN terminal using non-automatic TEI assignment, even if a condition for canceling a TEI value occurs, the ISDN terminal uses an ISDN terminal.
An object of the present invention is to provide an ISDN terminal device in which a DN terminal can automatically set a new TEI value and avoid a communication disabled state.

[0008]

According to the first aspect of the present invention,
Having interface means connectable to ISDN;
Q. of CITT Recommendation. In the ISDN terminal device which performs the LAPD procedure according to R.921 and performs the non-automatic TEI allocation, the network uses the TEI when the non-automatic TEI allocation is used.
If the multiple assigned value is detected, characterized by comprising a TEI value canceling means for canceling the TEI value in use, and a TEI value setting means for setting a new TEI value automatically.

[0009] The invention according to claim 2 has interface means connectable to ISDN, and Q.1 of CCITT recommendation. A TEI value release condition detecting means for detecting that a condition for releasing a TEI value from a network has occurred in an ISDN terminal device which performs a LAPD procedure according to R.921 and performs non-automatic TEI allocation; Sometimes, when a condition for releasing the TEI value from the network is detected, a TEI value releasing means for releasing the TEI value being used is stored in advance.
And a TEI value setting unit for automatically setting a new TEI value different from the previously set TEI value, and a TEI value setting unit for automatically setting a new TEI value.

[0010] The third aspect of the present invention is the first or second aspect.
In the ISDN terminal device described above, the TEI value that is newly automatically set is set to a random value within a specified range. According to a fourth aspect of the present invention, in the ISDN terminal device of the first or second aspect, the released TEI value is set so that the newly automatically set TEI value is adjacent to the released TEI value within a specified range.
A value obtained by adding or subtracting a predetermined constant from the value is set as the TEI value.

According to a fifth aspect of the present invention, there is provided the ISDN terminal device according to any one of the first to fourth aspects, further comprising display means for displaying a predetermined message to a user, wherein the TEI value is canceled when the non-automatic TEI assignment is used. A new TEI value is set and displayed to notify the user.

[0012]

According to the first or second aspect of the present invention, the non-automatic TE
In the ISDN terminal device that performs I assignment, even if the TEI is released, the ISDN terminal automatically generates a new TEI.
Is set, it is possible to avoid a communication disabled state due to the release of the TEI.

According to the third aspect of the present invention, since a random number (random value) is used as the TEI value that is newly automatically set, the possibility of occurrence of multiple allocation of TEI values can be reduced. According to the fourth aspect of the present invention, adjacent values before and after the canceled TEI value are used as the newly automatically set TEI value. Therefore, the TEI value is allocated and managed in a specific range for each ISDN terminal. T in such a situation
The possibility of occurrence of multiple allocation of EI values can be reduced.

According to the fifth aspect of the present invention, the user can easily manage the TEI by displaying the setting of the new TEI value on the display means and notifying the user.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. First, the configuration will be described. FIG. 1 is a view showing an I-type according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of an SDN terminal device.

In FIG. 1, reference numeral 1 denotes a system control unit (SC).
U: System Control Unit) controls the entire ISDN terminal device. Reference numeral 2 denotes a storage unit for storing transmission / reception data and parameters related to system control. Reference numeral 3 denotes an input unit, such as a scanner for reading a transmission original or the like and creating transmission data.

Reference numeral 4 denotes an output unit such as a plotter for recording and outputting received data on recording paper or the like. Reference numeral 5 denotes an operation port unit, which is a keyboard for performing a system control operation by the user and an L for notifying the user of a predetermined message.
A display such as a CD is provided.

Reference numeral 6 denotes a communication control unit (CCU: Communication).
Control Unit) controls communication between ISDN terminals via ISDN (Integrated Services Digital Network). 7 is a line termination unit (DSU: Digital Service Uni)
At t), the digital signal transmitted / received by the terminal device and the digital signal suitable for the transmission path are converted. Reference numeral 8 denotes a bus to which the respective units of the ISDN terminal device are connected, and which are mutually accessible.

FIG. 2 is a diagram showing a configuration of a communication control unit according to one embodiment of the present invention. In the figure, a communication control unit (CC
U) 6 has a D-ch call control unit 9 and a B-ch control unit 10, and the D-ch call control unit 9
It provides a physical / electrical interface for connecting to the channel call control (layer 1 to layer 3) and ISDN. The B-ch control unit 10 performs ISDN B-ch communication control.

FIG. 3 is a diagram showing a configuration example of the LAPD frame of the D channel layer 2. In the figure, each frame is defined in units of octets (8 bits), and although not shown, a service access point identifier (SA)
PI) is followed by a start flag indicating the start of the frame. Next, there is an address field for identifying the logical link, and a control field indicating what kind of frame this is, followed by an information field (not shown) for an information frame. After that, a frame check sequence (FCS: Frame Check Sequence) for detecting a reception error such as a transmission line error is performed.
ce) followed by an end flag (not shown) indicating the end of the frame.

The transmission order of bits on the D channel of this LAPD frame is as follows: bit 1 (b1), bit 2 (b2),... Of octet 1 shown in FIG. 3, and finally octet n (final octet). ) Bit 8 is sent. The address field is composed of two octets. Bit 1 of the first octet is an extension bit (EA), and bit 2 of the command / response bit (CR) is, for example, a non-automatic TEI assigned synchronous extended balanced mode setting (SABME: Set Asynchronous Balanced).
Mode Extended) A command for requesting a specific operation to the receiving side of the frame, such as a request for setting a logical link by a frame, or an unnumbered A (UA).
cknow-ledge) Indicates a response that reports an operation or a state executed as confirmation of a logical link setting by a frame. Also, bits 3 to 8 of the first octet constitute a SAPI indicating the type of service port provided by layer 2. Further, in bits 2 to 8 of the second octet, a TEI for identifying the terminal device is configured.

The TEI allocation procedure includes an automatic TE
There are I allocation and non-automatic TEI allocation, and values from 64 to 126 can be used as TEI values for automatic TEI allocation, and values from 0 to 63 can be used as TEI values for non-automatic TEI allocation. Therefore, the conventional ISDN terminal device normally uses an automatic TEI allocation procedure, and when the TEI is released, the IDN is transmitted to the network.
Activate the D acquisition procedure and perform communication using the TEI value given from the network. Thus, all TEIs were managed by the network.

However, when the non-automatic TEI allocation procedure is used in the conventional ISDN terminal device, the management of the TEI value is the responsibility of the user, and when the TEI is released by the ISDN terminal, the TEI value is notified to the user. The ISD until the user sets a new TEI value.
N terminal cannot activate D channel layer 2,
Transmission and reception were impossible.

Next, the operation will be described. The network is the TEI actually used by the terminal equipment connected to the interface.
It is checked periodically whether multiple allocation of values or TEI values has occurred. Specifically, a TEI value check request message is sent from the network to each terminal, and the action indicator (Ai: Action Indicator) and reference number (Ri: Reference Number) at this time are Ai = 127, R
Let i = 0. Upon receiving this, each terminal device sends the TEI value used by itself to Ai and the random number generated by each terminal device to Ri, and sends it to the network as a check response message. Here, each terminal device puts a random number in Ri in order to facilitate detection of multiple assignment in which a plurality of terminal devices use the same TEI value. When the network receives the check response message from all the terminal devices, the network updates the TEI management information based on this. Thus, TEI
Multiple assignment of values can be detected.

Therefore, in the embodiment according to the first aspect of the present invention, when the above-mentioned multiple allocation of the TEI value is detected at the time of using the non-automatic TEI allocation, the used TEI value is released and a new TEI value is released. Value is set automatically. For this reason, conventionally, only the cancellation of the TEI value is notified to the user, but in the case of the present embodiment, a new TEI value is immediately set, so that the state without the TEI value does not continue and the TEI value is not continued.
It is possible to avoid a communication disabled state due to the release of the I value.

FIG. 4 is a flow chart for explaining the operation of the ISDN terminal device according to the second to fifth aspects of the present invention. As shown in FIG.
The occurrence of the I release condition is detected. As the TEI release conditions, here, when an ID release message is received from the network, when an unsolicited UA response frame is received, a retransmission error of n200 times of the SABME command, n20 of a DISC (Disconnect: disconnect) command
There are 0 retransmission errors and the like. When the occurrence of any of the above-mentioned release conditions is detected, the TEI value in use is released in the same manner as in claim 1 (step 101), and a new TEI value is set.
Start the procedure for automatically setting the EI value (step 1
02).

As shown in the flow of step 102 in FIG. 4, as the TEI value to be newly set, 1) the released TE
Add any appropriate constant "X" to the I value, or conversely,
2) Any appropriate constant "X" is subtracted from the released TEI value, or 3) A random number generation system is used to set a random value within a range used for non-automatic TEI allocation. It is.

As described above, when an adjacent value before and after the released TEI value is set as a new TEI value,
In a situation where TEI values are allocated and managed within a specific range for each DN terminal, the possibility of occurrence of multiple allocation of TEI values can be reduced (the embodiment according to claim 4), and new automatic setting is performed. Even when a random value is used as the TEI value to be used, the possibility of occurrence of multiple allocation of the TEI value can be reduced (the third embodiment).

As described above, when the new TEI value is automatically reset after releasing the used TEI value, the user is informed of that (step 103). As means for notifying the user, as shown in the flow of step 103 in FIG. 4, 1) when displaying on an LCD, 2) when outputting from a plotter as a report, 3) as other means, for example, audio It can also be notified by a buzzer or the like. As a result, the user can easily manage the TEI.

[0030]

According to the first or second aspect of the present invention,
Even when the TEI is released by the ISDN terminal device that performs the non-automatic TEI assignment, the ISDN terminal automatically sets a new TEI, so that a communication disabled state due to the release of the TEI can be avoided. According to the third aspect of the present invention, since a random number is used for a TEI value that is newly set automatically, the possibility of multiple allocation of TEI values can be reduced.

According to the fourth aspect of the present invention, adjacent values before and after the TEI value are used for the TEI value to be newly set automatically, so that the TEI value is set within a specific range for each ISDN terminal.
T under the situation where I value is assigned and managed
The possibility of multiple allocation of EI values can be reduced.
According to the fifth aspect of the present invention, the fact that the new TEI value is set is displayed on the display means to notify the user, so that the user can easily manage the TEI.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an ISDN terminal device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a communication control unit according to one embodiment of the present invention.

FIG. 3 is a diagram illustrating a configuration example of an LAPD frame of a D channel layer 2.

FIG. 4 is a flowchart illustrating the operation of the ISDN terminal device according to the second to fifth aspects of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 System control part 2 Storage part 3 Input part 4 Output part 5 Operation port part 6 Communication control part (CCU) 7 Line termination unit (DSU)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-62003 (JP, A) JP-A-5-56188 (JP, A) JP-A-4-344740 (JP, A) 199264 (JP, A) JP-A-4-362842 (JP, A) JP-A-4-212439 (JP, A) JP-A-4-302235 (JP, A) JP-A-5-122295 (JP, A) JP-A-4-3548 (JP, A) JP-A-3-55995 (JP, A) JP-A-2-2783 (JP, A) JP-A-2-111133 (JP, A) (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 29/10 H04L 29/08 H04L 12/02 H04M 11/00 303 H04Q 5/00 H04M 3/00 H04M 3/22

Claims (5)

(57) [Claims] 1. An apparatus having interface means connectable to an ISDN, comprising: LAP according to 921
ISDN performing D procedure and non-automatic TEI allocation
In the terminal apparatus, if it is pre-Symbol multiplex assignment detection of TEI values by non-automatic TEI assignment using the network during the TEI value canceling means for canceling the TEI value in use, to set a new TEI value automatically An ISDN terminal device comprising: a TEI value setting unit. 2. It has an interface means connectable to an ISDN, and has Q.T. LAP according to 921
ISDN performing D procedure and non-automatic TEI allocation
In the terminal device, a TEI value release condition detecting means for detecting that a condition for releasing the TEI value from the network has occurred, and if the condition for releasing the TEI value from the network has been detected when the non-automatic TEI allocation is used, the terminal is in use. T to release the TEI value of
An ISDN terminal device comprising: an EI value release unit; and a TEI value setting unit that automatically sets a new TEI value different from the TEI value held in advance . 3. The ISDN terminal device according to claim 1, wherein the TEI value automatically set newly is set to a random value within a specified range. apparatus. 4. The ISDN terminal device according to claim 1, wherein the newly automatically set TEI value is adjacent to the released TEI value within a prescribed range. An ISDN terminal device wherein a value added or subtracted by a predetermined constant is set as a TEI value. 5. The ISDN terminal device according to claim 1, further comprising display means for displaying a predetermined message to a user, wherein the TEI value is canceled when the non-automatic TEI allocation is used, and a new TEI value is automatically set. An ISDN terminal device characterized in that the setting is displayed to notify the user.