KR100742323B1 - Faximily for using non-normalized fax protocol and method thereof - Google Patents

Abstract

A fax data transceiver is disclosed. According to the fax data transmitting / receiving apparatus, a communication module for receiving information on a function capable of supporting the fax from an external fax on which a call is established, a scanning unit for generating fax image data to be sent to an external fax, and an external fax are provided. And determining a fax image data transmission mode in accordance with a supportable function, and controlling the communication module to transmit information about the transmission mode to an external fax using a predetermined non-standard frame. Accordingly, the risk of eavesdropping or eavesdropping by a third party can be reduced even without additional hardware.

Fax, NSF, NSS

Description

Fax data transceiver using non-normalized fax protocol and its method {Faximily for using non-normalized fax protocol and method}

1 is a flowchart illustrating a general method of transmitting a document using a fax data transmitting and receiving apparatus;

2 is a block diagram showing the configuration of a fax data transmitting and receiving apparatus according to the present invention;

3 is a flowchart for explaining a method of transmitting data using a fax data transmitting and receiving apparatus according to the present invention;

4 is a flowchart illustrating a fax protocol for data transmission in a data transmission system according to the present invention.

Explanation of symbols on the main parts of the drawing

110: control unit 120: communication module

130: printing unit 140: scanning unit

150: sensor unit 160: storage unit

170: operation panel 180: speaker

190: LCD

The present invention relates to a fax data transmitting and receiving apparatus, and more particularly, to maintain security by notifying an external fax of a transmission mode for data to be transmitted using a predetermined non-standard frame without providing a separate security device. A fax data transceiver and a data transmission / reception method thereof.

With the recent increase in the use of fax data transceivers such as fax machines, the performance and additional functions of fax data transceivers have been gradually improved. The fax data transmitting and receiving device is a device for sending and receiving information data to be transmitted in the form of a document, and it is not only an existing method of transmitting and receiving fax data using a conventional public switch telephone network (PSTN) but also the currently developed internet communication technology. It is also possible to send and receive fax data through the Internet network.

In general, a fax data transceiver, that is, a facsimile is a scanning unit capable of reading a predetermined document, a printing unit capable of outputting received data and data scanned through a scanner, and a telephone line connected to a telephone public network. It refers to a device in which a remote facsimile and a communication means capable of transmitting / receiving data are integrated.

A user who wants to send a document to another user can enter the other party's phone number in the fax and then take the document on the fax stand and press the send button to send the document data.

In this case, the facsimile scans the document using a scanner, and then transmits the scanned data through a call established with the other facsimile. In the other party's facsimile, the transmitted data is stored and then printed on a sheet using a printing unit.

1 is a flowchart for explaining a method of transmitting and receiving data between facsimile machines. According to FIG. 1, once a user inputs a transmission button of a facsimile, the facsimile checks the input telephone number to form a call line with the corresponding counterpart facsimile (S10). In order to establish a call, the sending and receiving faxes must first exchange certain tones to inform each other that they are faxes. That is, when a communication line with the receiving fax machine is connected, the sending fax periodically transmits a 0.5 second 1100 Hz Calling Tone (CNG) tone every three seconds, and the receiving fax sends a 2100 Hz CED (3 seconds long). Answer with a Called Station Identification tone. If the sending fax recognizes the CED tone of the receiving fax, the CNG tone is interrupted and the call setup procedure is completed.

Next, the sending side fax checks the function of the receiving side fax, determines a mode to transmit, and prepares to transmit the fax image data (S20). First, the sending and receiving fax machine confirms each other's functions by exchanging binary data, and selects common ones to determine a transmission direction and a method. This procedure begins by sending a Digital Identification Signal (DIS) on the receiving fax machine. The DIS is a packet indicating the function of the receiving side fax and includes information such as group, transmission speed, vertical resolution, image encoding, paper width, maximum paper length, handshaking speed, and error correction mode. The receiving side fax receiving the DIS selects the functions of the receiving side fax recorded in the DIS to determine the data transmission mode, and then informs the receiving side fax through the DCS (Digital Command Signal). If the receiving fax machine agrees, it responds with CFR (Confirmation to Receive) and terminates the procedure.

Incoming and outgoing faxes can transmit one or two optional frames as well as the required control frames such as DIS and DCS.

That is, characteristics not included in T.30 but only by the fax sending this frame can be notified by sending and receiving Non Standard Facilities (NSF) and Non Standard Facilities Setup (NSS) frames. At this time, the receiving side fax transmits to the sending side through the NSF (Non Standard Facilities) frame which notifies the functions that can be supported. Is transmitted using NSS (Non Standard Facilities Setup) frame.

In addition, the receiving side fax notifies the sending side fax of the receiving side fax ID (Fax number) through the CSI (Called Subscriber Identification), and the sending side fax has the ID of the sending side fax through the Transmitting Subscriber Identification (TSI) frame. You can notify.

An irregular frame, such as an NSF or NSS frame, consists of the fax manufacturer's country code, manufacturer code, and additional ASCII information, which is limited to three seconds in length. This frame is processed only if the country code and manufacturer code of the receiving fax is equal to the first 3 bytes of the frame.

If the transmission mode is determined because the exchange of the required control frames has been completed successfully, the sending fax machine sends a '0' for 1.5 seconds to the receiving fax machine to check the status of the link. This is called training, and training continues at lower transmission speeds until the receiving fax sends a CFR.

When the transmission mode is determined and the transmission preparation is completed, the sending fax machine transmits the fax image data to the receiving fax (S30). When sending a message by coding a document image in the manner specified in T.4 or T.6, the end of one page is always marked as Return To Control (RTC) so that control frames can be exchanged again. The control frame after the RTC determines whether further transmission of another page in the sending fax or completion of the transmission.

In other words, when the transmission of one page is finished, the sending side fax checks whether additional pages remain to be transmitted (S40). If there are no more pages to send, EOP (End Of Procedure) is sent, and if there are additional pages to send, it sends MPS (Multi-Page Signal) or EOM (End Of Message) and transmits the next page.

The receiving side fax checks the quality of the received fax image data when the EOP is transmitted, and responds with an MCF frame if there is no problem. When the sending side fax receives the MCF frame, the transmission and reception process is terminated by transmitting the DCN frame to release the line connection (S50).

On the other hand, according to the conventional fax data transmission and reception method, the fax data communication information is transmitted using standard fax protocols (DIS, DCS) defined in ITU-T T.30. Since the contents of the DIS and DCS frames are defined in the T.30 fax protocol, it is easy to know the fax communication mode if a third party taps / taps the communication line, so that the transmitted fax image data can be easily reproduced. . Therefore, when transmitting and receiving data in the conventional manner, there was a problem in that such a security vulnerability should be taken or an additional security device should be additionally installed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a transmission mode for data to be transmitted to a receiving side fax using a non-standard frame so that even if no additional security equipment is added. The present invention provides a fax data transceiver and method for maintaining security for three parties.

In order to achieve the above object, a fax data transmitting and receiving apparatus according to the present invention, a communication module for receiving information on a function capable of supporting the fax from an external fax in which a call is established, a fax to be transmitted to the external fax A scanning unit for generating image data, and after determining the fax image data transmission mode according to a function capable of supporting the fax, the communication module to transmit information about the transmission mode to the external fax using a predetermined non-standard frame. It includes a control unit for controlling.

Preferably, the communication module may receive the function information transmitted using a non-standard facilities (NSF) frame, and the control unit transmits information on the transmission mode to a non-standard facilities setup (NSS) frame. Can be sent using.

More preferably, the apparatus for transmitting / receiving fax data according to the present invention includes a control panel for allowing a user to input a predetermined control signal, a printing unit for printing fax data received from an external fax data transmitting / receiving apparatus, and storing received fax data. It may include a storage unit, a sensor unit for sensing whether there is a document to be transmitted in the fax data, an LCD for displaying the current state and operation of the fax data transceiver.

On the other hand, the data transmission and reception method according to the present invention between the sending fax and the receiving fax, (a) the sending fax determines the transmission mode by checking the function of the receiving fax, (b) the determined transmission mode Transmitting information about the to the receiving side fax using a predetermined non-standard frame, and (c) the transmitting side fax transmitting the fax image data according to the transmission mode.

In this case, step (a) comprises: (a1) establishing a call between the sending side fax and the receiving side fax, and (a2) the function information provided by the receiving side fax with a predetermined non-standard frame. It is preferable to include the step of transmitting to the sender using the fax.

Further, step (a2) may be performed by the receiving side fax transmitting the function information using a non-standard facilities (NSF) frame.

Meanwhile, in step (b), the sending side fax may transmit information on the transmission mode using a non-standard facilities setup (NSS) frame.

In this case, the information on the transmission mode transmitted through non-standard frames such as NSF and NSS may include information on modem speed, image data resolution, error compensation mode, color mode, and image data compression mode.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the present invention.

2 is a block diagram showing the configuration of a facsimile 100 according to an embodiment of the present invention. 2, the facsimile 100 includes a control unit 110, a communication module 120, a printing unit 130, a scanning unit 140, a sensor unit 150, a storage unit 160, and an operation panel 170. ), A speaker 180, and an LCD 190.

The operation panel 170 has a plurality of operation buttons for the user to operate the facsimile 100. The user takes a document to be sent to a paper input port (not shown) of the facsimile 100, enters a phone number of the other party's facsimile using the operation panel 170, and transmits the document data by inputting a transmission button. do.

The sensor unit 150 is provided at a paper input port through which a document to be transferred is inserted, and serves to detect whether a document is to be transferred, and the LCD 190 stores data such as system information and information on the overall operation of the facsimile apparatus. Display it so that the user can recognize it.

The controller 110 controls overall operations of the facsimile according to a system program for operating the facsimile set in the storage 160. That is, when the transmission command is input through the operation panel 170 and the sensor unit 150 recognizes that the document to be transmitted is received, the image unit in digital form is controlled by scanning the image recorded in the document to be transmitted by controlling the scanning unit 140. Convert to The converted image is stored in the storage 160.

The storage 160 stores not only the scanned fax image data but also received fax image data, a registered telephone number, a system program for operating the fax, protocol data, and the like.

The printing unit 130 prints image data received from an external fax and stored in the storage unit 160 on a sheet of paper.

When the reception request signal is input from the public telephone network, when the operation command of the operation panel 120 is input, when the transmission / reception of fax data is terminated, and the printing operation of the printing unit 170 is terminated. If a case occurs, a preset alarm sounds.

The communication module 120 forms a call loop of a public switching telephone network (PSTN), and transmits various data frames (NSF, NSS, DIS, DCS, etc.) for fax data and fax data to a counterpart fax. It will send and receive to each other.

Looking at the data transmission and reception process performed in the facsimile 100 according to the present invention, first, when a transmission command is input from the user, the facsimile 100 generates a dialing signal for the receiving side fax and the terminal that is now calling the receiving side fax The CNG tone is transmitted periodically to indicate that it is a fax. In the receiving fax machine, a call to the facsimile 100 can be established by transmitting a CED tone in a manner of indicating that the terminal that is responding is a fax.

Next, the transmit and receive faxes exchange a series of binary signals to determine a mode for transmitting the fax image. As described above, the receiving side fax transmits the NSF, CSI, and DIS signals to the transmitting side fax 100, and the receiving side fax 100 confirms the information that the receiving side fax can support from the received signals, and then views the fax. The transmission mode for the data is determined, and the NSS, TSI, and DCS signals are transmitted to the receiving side fax.

At this time, DIS signal and DCS signal are the standard fax protocol defined in ITU-T T.30 as a signal transmitted to inform all functions of receiving fax. Therefore, such a standard fax protocol has a risk of eavesdropping or eavesdropping when a third party intercepts a communication line and immediately understands the meaning of the signal.

According to the present invention, the communication module 120 exchanges data to be exchanged using the receiving side fax, the DIS frame, and the DCS frame using non-standard frames such as the NSF frame and the NSS frame. Since such non-standard frames are used differently for each fax manufacturer or fax model, information on the transmission mode cannot be recognized even if the same product is not used, even when tapping and tapping. Therefore, printing the intercepted and eavesdropped fax image data results in an unrecognizable document.

Accordingly, the facsimile 100 can enhance the security of the contents of the fax image data transmitted and received even without any hardware.

3 is a flowchart illustrating a method of transmitting / receiving fax image data using the facsimile 100 according to the present invention. According to FIG. 3, once a data transmission command is input, the facsimile 100 establishes a call with the receiving side fax (S310).

The receiving side fax transmits a function capable of being supported to the transmitting side facsimile 100 using a non-standard frame (S320). In this case, security can be enhanced by transmitting using a non-standard frame, that is, a protocol other than a standardized protocol such as a DIS frame. Preferably, it can be transmitted using an NSF frame.

On the other hand, the transmitting side facsimile 100 determines the transmission mode by checking the function of the receiving side facsimile from the received non-standard frame (S330). That is, the transmitting side facsimile 100 determines whether to transmit the fax image data in a function such as an error correction mode, a color mode, an image data compression mode, as well as a modem speed and image data resolution to be transmitted.

After determining the transmission mode of the data, the transmitting side facsimile 100 transmits the information about the determined transmission mode to the receiving side facsimile using a predetermined non-standard frame (S340). In this case, the transmitting side facsimile 100 may transmit using the NSS frame in response to the NSF signal. That is, by checking the fax information of the NSF signal, if the sender's fax 100 is the same as the sender's fax 100, not only the function of the sender's fax is used for the fax transmission but also the information to be transmitted through the standardized DCS frame using the NSS signal. It will be sent to the receiving fax.

On the other hand, the transmit / receive fax can mutually notify the sender's fax ID and the receiver's fax ID by exchanging Called Subscriber Identification (CSI), Transmitting Subscriber Identification (TSI) signals, etc. as an optional frame. In general, the data exchanges thus far are transmitted at approximately 300bps.

When the mode for transmitting the fax image data is determined in this way, the sending side facsimile 100 transmits the fax image data (S350). For data transmission, first, the sending fax machine sends a TRAINING signal for 1.5 seconds at the maximum speed that can be sent (14.4 Kbps or 9.6 Kbps) and a TCF (Training Check Flag) signal. Receiving side fax properly receiving the TCF signal sends a CFR signal to the sending side fax 100 to indicate that there is no abnormality, otherwise it sends a FTT (Failure To Train) signal. Receiving the FTT signal, the sending side fax 100 lowers the transmission rate of the training signal by one step and tries again. If it fails several times, it is considered a failure and the user is notified of the transmission failure. When the CFR signal is received, the sending fax machine starts sending the fax image data.

In the receiving FAX, by checking whether the EOP signal is received, it is determined whether there are more messages to be transmitted (S360). As described above, the EOP signal is a signal indicating that all pages have been transmitted. If there are more pages to send or if there is a change in the transmission mode, EOM signal or MPS signal is sent.

The receiving side fax receiving the fax image data checks whether there is an error in the received data, and if there is no error, the call is released (S370). In other words, the receiving fax, which has received all the fax image data well, sends the MCF signal to the sending fax, and if the receiving fax detects an error in the document image data, the receiving fax receives an RTN (Retrain Negative) signal or RTP (Retrain) if it exceeds the tolerance. Positive) Sends a signal to the sending fax. The sending fax machine receiving the MCF signal sends a DCN signal to the receiving fax machine to notify disconnection. At this moment, the sending and receiving faxes complete the transmission and reception of fax data by disconnecting the telephone lines.

4 is a protocol flowchart illustrating a process of data transmission and reception between a sending side fax and a receiving side fax according to a chronological order. According to Fig. 4, once, the sending fax and the receiving fax establish a call by exchanging CNG and CED.

When the call is established, the receiving side fax transmits information about the supportable function that was transmitted in the existing DIS frame using the NSF frame. Therefore, only the common functions and the corresponding faxes will be notified. In this case, by selectively transmitting the CSI, the receiving side fax ID can be notified.

On the other hand, the sender fax sets the modem speed, data resolution, error compensation mode, color mode, data compression mode, etc. to transmit data according to the confirmed function information. The configured information is sent to the receiving fax via NSS. That is, by transmitting information transmitted in the existing DCS frame using the NSS frame, security can be enhanced from the third.

Then, after exchanging TCF and CFR to test whether there is no problem on the circuit, the image data is transmitted, and when the transmission is successfully completed, call release is performed.

According to this, non-standard frames such as NSF and NSS are different according to facsimile manufacturers and facsimile models, so even if a third party intercepts or intercepts, a normal fax document cannot be obtained unless the non-standard frames are recognized.

As described above, according to the present invention, by transmitting data to be transmitted using a standardized protocol through non-standard protocols such as NSF and NSS, security of a third party can be maintained without additional hardware.

In addition, although the preferred embodiment of the present invention has been shown and described above, the present invention is not limited to the specific embodiments described above, but the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Claims (8)

A communication module for receiving a non-standard facilities (NSF) frame in which function information capable of supporting the external fax is recorded from an external fax on which a call is established; A scanning unit generating fax image data to be transmitted to the external fax; and After selecting a function corresponding to its own function among the function information to determine the transmission mode of the fax image data, the communication module to record the transmission mode information in the Non-Standard Facilities Setup (NSS) frame to transmit to the external fax And a control unit for controlling the  And the function information and the transmission mode information are each information defined to be transmitted through a standard frame on a predetermined fax standard. The method of claim 1, The non-standard facilities (NSF) frame is a fax data transmission and reception device, characterized in that recorded in the T.30 standard function information defined to be transmitted through the DIS (Digital Identification Signal). The method according to claim 1 or 2, The non-standard facilities setup (NSS) frame is a fax data transmitting and receiving device, characterized in that the information defined to transmit through the Digital Command Signal (DCS) in the T.30 standard is recorded. In the method of transmitting and receiving data between the sending fax and the receiving fax, (a) the sending fax establishes a call with the receiving fax; (b) the sending-fax receiving a Non-Standard Facilities (NSF) frame in which the function information capable of supporting the receiving-fax is recorded from the receiving-fax; (c) the sending-fax selecting a function corresponding to its own function from the function information to determine a transmission mode of the fax image data; (d) the sending side fax recording the transmission mode information in a Non-Standard Facilities Setup (NSS) frame and transmitting the same to the receiving side fax; and (e) sending, by the sending fax, the fax image data according to the transmission mode;  And the function information and the transmission mode information are each information defined to be transmitted through a standard frame on a predetermined fax standard. delete The method of claim 4, wherein The non-standard facilities (NSF) frame is a method of transmitting and receiving data, characterized in that the functional information defined to be transmitted through the Digital Identification Signal (DIS) in the T.30 standard is recorded. The method of claim 4, wherein The non-standard facilities setup (NSS) frame is a method of transmitting and receiving data, characterized in that the information defined to transmit through the Digital Command Signal (DCS) in the T.30 standard is recorded. The method of claim 4, wherein The transmission mode information includes information on at least one of information on modem speed, image data resolution, error compensation mode, color mode, and image data compression mode.

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