JPH04183148A - Terminal adapter - Google Patents

Abstract

PURPOSE:To obtain a terminal adapter that can realize the security of cipher when one wishes to open communication with a particular party by switching communication rate matching system from the standard system to its own system for data communication. CONSTITUTION:When carrying out ordinary communication, a control section 16 switches switch circuits 15a and 15b so as to select a format circuit section 14a that carries out the TTC standard rate matching. On the other hand, when communicating with a particular terminal, the control section 16 switches the switches 15a and 15b so as to select a format circuit section 14b that carries out communication rate matching using its own system that is different from the TTC standard rate matching. With this, a particular party can be specified easily securing cipher talking.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) This invention relates to a terminal adapter for connecting existing data terminals to a digital network.

(Prior Art) A terminal adapter used to connect an existing data terminal to a digital network, such as an I5DN (Integrated Digital Service Network), performs speed matching of data communication between the I5DN and the existing data terminal.

By the way, the conventional terminal adapter is this l5DN
JT will match the speed of data communication between
-V, 110, and other TTC standards. For this reason,
It is extremely convenient because it can be connected to all terminals that comply with the TTC standard.

However, when a certain data terminal device wishes to communicate only with a specific data terminal device, conventional terminal adapters have the problem of not being able to specify the other party's terminal device.

One way to solve this problem is to register the telephone number of the calling party and identify the other party using this telephone number. However, with this method, if the calling terminal device is set not to display the telephone number, the called party cannot identify the other party, and therefore the call cannot be received.

Also, the characteristics of l5DN (here, there is a method of using the subaddress to identify the tth party, but in this case, it is necessary to set the same subaddress on both the calling and called terminals). There was also a problem that if the terminal was on the same bus, it would not be possible to transmit, or it would be possible to monitor the other party's signal, which could be confidential.

(Problem to be solved by the invention) With conventional terminal adapters, when trying to communicate only with a specific party, it is necessary to set the same address and subaddress on both terminal adapters. It was inconvenient, and there was also the problem that people in the same house were being monitored.

Therefore, an object of the present invention is to provide a terminal adapter that can eliminate this problem and easily maintain confidentiality.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a means for connecting to a digital network, a means for connecting to an existing data terminal device, and a speed matching method using a standard speed matching method between the digital network and the existing data terminal device. A means for realizing data communication by performing matching, a means for realizing data communication between the digital network and existing data terminal equipment using a unique speed matching method different from the standard speed matching method, and If data communication is to be performed using the speed matching method and it is desired to communicate with a specific partner, the system is configured to include a control means for switching from the standard speed matching method to a unique speed matching method and performing data communication.

(Function) Normally, communication is performed using a standard speed matching method, and when it is desired to communicate only with a specific terminal, communication is performed by switching to a unique speed matching method that is different from the standard speed matching method.

This allows you to easily identify the other party and maintain confidentiality.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic configuration of an embodiment of a terminal adapter of the present invention. In FIG. 1, the terminal adapter is an I5DN line interface section that is connected between an I5DN subscriber line 11 connected to an I5DN and a data line 17 connected to a data terminal equipment (DTE), and forms an interface with the I5DN. 12. DTE interface unit 1 that interfaces with the data terminal device
3. Format circuit section 1 that performs TTC standard speed matching
4a, a format circuit section 14b that performs speed matching using a unique method different from the TTC standard speed matching method, switch circuits 15a and 15b that switch between the TTC standard speed matching method and an original speed matching method, switch circuits 15a and 15b;
The control section 16 controls nine switching operations.

In this embodiment, in the case of normal communication, the control unit 16
The switch circuits 15a and 15b are switched to select the format circuit section 14a that performs TTC standard speed matching, and when communicating with a specific terminal, the control section 16 switches the switch circuits 15a and 15b to select the TTC standard speed matching. The format circuit section 14 performs speed matching using a different unique method.
Switch to select b.

FIG. 2 shows the detailed configuration of the terminal adapter of this embodiment. In FIG. 2, the receiver circuit 20 is
The digital signal sent from the 15DN and transmitted through the home bus 21 is received. The frame synchronization circuit 22 detects a frame from the digital signal received by the reception circuit 20 and provides a timing signal to the frame decomposition circuit 23.

The frame decomposition circuit 23 decomposes the frame of the digital signal into a B channel and a D channel based on the timing signal. The D channel control circuit 24 detects each data, flag, and control signal in the D channel input from the frame decomposition circuit 23 during reception, and forms a D channel for the control signal to be transmitted during transmission. . The format circuit section 25a is a TTC standard JT-
DTE2 connected externally to the device according to V.110
6 and the B channel of the I5DN.

The format circuit section 25b is the format circuit section 25b.
Performs unique speed matching different from a. Switch circuit section 2
7a and 27b selectively switch the format circuit sections 25a and 25b that perform the above-mentioned two speed matching.

The DTE interface section 28 connects the DTE 26 and the speed matching section, and controls the DTE. Frame assembly circuit 29
Assembles the B channel given from the switch circuit section 27a and the D channel manually inputted from the D channel control circuit 24 into a frame. The transmitting circuit 30 sends a signal given from the frame assembling circuit 29 to the home bus 21 to be transmitted to the other party's terminal. A central processing unit (CPU) 31 controls the entire device, and includes the control section 16 shown in FIG. 1. The instruction input unit 32
It is composed of keys and the like for giving instructions corresponding to various operations to the U31i. The display 33 is an LC
A display device consisting of D, etc., used to display required information.

The memory 34 includes a ROM that stores an operating program for the CPU 31 and a RAM that is used as a working register.

In the terminal adapter configured as above,
The CPU 31 executes the programs shown in the flowcharts shown in FIGS. 3 and 4. Here, the flowcharts shown in FIGS. 3 and 4 both show the operation of the terminal adapter provided on the destination side.

First, the flowchart shown in No. 3M will be explained.

Now, by using the setting switch or setting sequence of the instruction input section 32, the speed matching procedure is set according to the TTC standard JT-V, 1.
10 to a unique format (step 401).

Here, when there is an incoming call (step 402), Bch is connected.

For example, if the frame for which speed splicing is to be performed is a frame as shown in Figure 5, if the same frame is transmitted (step 403), frame synchronization is performed (step 404) to realize data communication. (Step 405).

If the other party transmits the TTC standard V, 110 frame, the first bit of octet 5 is different, so frame synchronization becomes impossible and the transmission is disconnected (step 406).

Therefore, frames that can be transmitted in the TTC standard format are cut off, and communication can only be performed with the other party that has been transmitted in the proprietary format.

In the example above. Only the 1st bit of RAI octet 5,
Examples different from the standard are shown in Figure 6 (A), (B), (
Even if the bit position when converting to 64 kbps is changed as shown in C), it can be implemented in exactly the same way.

The speed matching function of the terminal adapter is based on the TTC standard JT-
Standardized by vtio, thick 19.2kb
It is divided into below ps and above.

As an example, a case of 19.2 kbps or less is shown.

As shown in FIG.
This is done in three stages: AI and RA2. Function block RA
O has a conversion function from asynchronous to synchronous function,
Perform stop bit operation and set 2 x600bl)s
Create a bit string defined by (no ~ 5). The functional block RAI sets the user speed to 2kx8kbps (k-0
, 1, 2) called the next faster intermediate speed. For example, if the user speed is 9600 bp
The intermediate speed in the case of s is 16 kbps. The conversion is performed by assembling the frame structures shown in FIGS. 8 and 9 (A) to (F).

RA2 also has a function to convert to 64kbps.

The method of conversion is shown in FIG.

In the frame of FIG. 8, "0" in octet number O and "1" in bit number 1 of octets 1 to 9 are a frame synchronization pattern. The format circuit section 25a, which performs speed matching of V.V.110, detects this frame pattern and performs frame synchronization.

Next, the flowchart shown in FIG. 4 will be explained.

First, incoming call step 411), normal V.

Assume that 110 frame synchronizations have been performed. Here, as shown in FIG. 11, Sl, S3. S6. S8 is 0N10
Assume that the switching request signal is a pattern in which the FF is repeated for three frames, for example. When the above patterns are mutually received (step 412), the frame of V, 110 is switched to a unique frame (step 413).

Then, when unique frame synchronization is established (step 4
14), data communication is started (step 415).

Further, if frame synchronization is not established in step 4]4, the connection is disconnected (step 416).

Note that the request signal for switching the speed matching frame can be implemented in various forms other than the above-mentioned measuring instruments, and if the unique frame is also modified in various ways by the switching signal, it is possible to maintain even more secrecy. becomes.

Further, in this embodiment, only the called side is shown, but it can be implemented in exactly the same way for the calling side.

Additionally, the rate matching method can be similarly implemented by simply sampling the signal from the DTE.

〔Effect of the invention〕

As explained above, according to the present invention, TTC8lt
It is equipped with a standard speed matching method and a unique speed matching method, and data communication is normally performed using the TTC standard speed matching method, and when communicating with a specific partner, it is possible to switch to use the unique speed matching method. It has the advantage that it is easy to distinguish between a specific party and a general party, and it also maintains confidentiality.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram showing an embodiment of the present invention;
Figure 2 is a block diagram showing one embodiment of this invention, Figures 3 and 4 are flowcharts to explain the operation of this embodiment, and Figures 5 and 6 explain the unique speed matching method. The diagrams, Figures 7 to 10, are based on the TTC standard JT-V.
, 110, and FIG. 11 is a diagram showing an example of a control signal requesting switching of the speed matching method. 11...I SDN subscriber line, 12...15DN line interface unit, 13...DTE interface unit, 14a...format circuit unit that performs TTC standard speed matching, 14b...speed matching using original method Format circuit unit for matching, 15a, 15b...Sinch circuit, 16...Control unit, 17...Data line, 20...Reception circuit, 21...Internal bus, 22...Frame synchronization circuit, 23... Frame decomposition circuit, 24... D channel control circuit, 25a, 25b... Format circuit section, 2
7a, 27b...Switch circuit section, 28...DTE
Interface section, 29... Frame assembly circuit, 30
. . . Transmission circuit, 31 . Kiripano #I-J two-former, G (9600bps) 3-way yodomabetsukai Figure 7 JT-Vloo 7-A structure drop RAl (CCITT V, 11
0) Figure 9 N=2 sentence is 4th sentence Figure 9 N=1.2 or 1. t4 eaves, Figure 9, RA2 (Dormitory 2ρ Mar!! Intermediate) BCh 64kbps, middle seat, luxury 8kbps, Figure 10, Figure 11

Claims (4)

[Claims] (1) A means for connecting to a digital network, a means for connecting to a data terminal device, a means for performing speed matching using a standard speed matching method between the digital network and the data terminal device, and realizing data communication; A means for realizing data communication between a network and a data terminal device using a unique speed matching method different from the standard speed matching method mentioned above, and a method for communicating with a specific party by normally performing data communication using a standard speed matching method. A terminal adapter characterized in that it comprises a control means for switching data communication from the standard speed matching method to a unique speed matching method when desired. (2) The standard rate matching method is the TTC standard JT-
V. 110 or JT-X. 30. The terminal adapter according to claim 1, wherein the terminal adapter is 30. (3) The terminal adapter according to claim 1, wherein the control means switches the speed matching method when receiving a specific control signal during communication or incoming call. (4) The terminal adapter according to claim 1, wherein the control means includes instruction means for instructing switching of the speed matching method by a setting switch or a setting sequence.