JP2002368832A - Protocol converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protocol converter that can prevent a response between facsimile terminals from being delayed and carry out stable facsimile transmission. SOLUTION: The protocol converter has a reception section 100 including a header termination section 101, a type information analysis section 102 that analyzes type information, a buffer 104 that stores IFP(Internet Facsimile Protocol) data, a buffer control section 103 that controls a storage amount of the IFP data in the buffer 104 on the basis of the analysis result by the type information analysis section 102, a data conversion section 105 that extracts the IFP data from the buffer 104 and converts the data into data in compliance with the T.30 protocol, and a modem 106 modulates the T.30 protocol data into a modem signal and transmits the signal to a facsimile terminal. The reception section 100 analyzes the type information of the IFP data and controls the storage amount of the buffer on the basis of the analysis result so as to decrease a delay time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protocol conversion apparatus, and more particularly, to a group 3 facsimile apparatus and an ITU.
-T Recommendation T. A function of transmitting and receiving image information by executing 30 procedures, and an Internet Protocol
ITU-T via a network (hereinafter simply referred to as “IP network”)
Recommendation T. The present invention relates to a protocol conversion device having a function of transmitting and receiving image information by executing 38 procedures.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 1, in performing facsimile communication using an IP network 50, ITU-T
Recommendation T. Facsimile apparatuses 30 and 40 of the T.38 procedure (hereinafter, simply referred to as “T.38 procedure”) and the T.38 procedure. 38 procedure to ITU-T Recommendation T.38. 30 procedures (hereinafter simply referred to as “T.30
In order to absorb the transmission fluctuation of the IP network 50, the protocol converters 10 and 20 that perform the protocol conversion to “procedure”) store IP packets from the IP network 50 in a reception buffer, and then perform facsimile reception processing. I was

That is, the protocol converters 10 and 20
As shown in FIG. 6, an IP packet is received, an IP header and a UDP / TCP header are terminated at a header terminating unit 601, and an Internet Facsimile Protocol (IFP) packet is accumulated in a buffer 602. The data conversion unit 603 converts Internet facsimile protocol data (hereinafter, simply referred to as “IFP data”) into T.P. Converted to 30 procedure data. Then, the modem 604 has a The data is modulated and sent to the receiving facsimile machine.

[0004]

However, in the above-mentioned conventional protocol converter, the output of data to the facsimile apparatus is stored by storing the packets in response to the fluctuation of the packet transmission interval of the IP network 50. It is always possible. When the fluctuation of the IP network 50 increases, the amount of packet storage increases, so that the delay time required for storage increases. Thereby, the signal transmitted by the image transmitting facsimile apparatus is received by the image receiving facsimile apparatus, a response signal to the signal is transmitted by the image receiving facsimile apparatus, the response time until the image transmitting facsimile apparatus receives, The response time in the reverse direction becomes longer. The response time T. If the limit of the response time of the control signal between the facsimile machines defined by the 30 procedures is exceeded, the communication procedure is interrupted.

For this reason, T.P. 38
Procedure facsimile machine and T.C. When performing image information communication with a 30-step facsimile apparatus, if the delay time of the IP relay section fluctuates greatly, the procedure cannot be established before the communication of image data, resulting in a communication error and facsimile transmission. There was a problem that can not be performed.

In particular, conventionally, as shown in FIG. 4 (a), the amount of IFP data stored in a buffer 602 (see FIG. 6) is determined when a high-speed signal of a facsimile apparatus is received regardless of the type of data stored. Receive buffer 602
Has been controlled to a value a that does not cause underflow, so that even when a control signal is received, the same delay time as the delay due to the accumulation of the high-speed signal occurs, and communication abnormalities are more likely to occur.

Accordingly, the present invention has been made in view of the above-mentioned problems in the conventional protocol converter, and a protocol converter capable of preventing a response delay between facsimile apparatuses and performing stable facsimile transmission. The purpose is to provide.

[0008]

In order to achieve the above object, an invention according to claim 1 is a protocol conversion device, comprising a group 3 facsimile device and an ITU-T Recommendation T.3.
30 function for transmitting and receiving image information by executing the procedures described in ITU-T Recommendation T.30 via an IP network. A protocol conversion device having a function of transmitting and receiving image information by executing a procedure of ITU-T Recommendation T.38. 38 types of IFP data type information are analyzed, and the amount of IFP data stored in the buffer is controlled based on the analysis result.

According to the first aspect of the present invention,
Analyzes the type information of the FP data, determines whether it is a high-speed signal or a control signal, controls the amount of IFP data stored in the buffer by either the high-speed signal or the control signal, and has less delay effect than the high-speed signal The delay time can be reduced by reducing the amount of accumulation of the control signal. Thereby, a response delay between the facsimile apparatuses can be prevented, and stable facsimile transmission can be performed.

According to a second aspect of the present invention, as a preferred embodiment of the protocol conversion apparatus according to the first aspect, a header terminator for terminating an IP header, a TCP header and a UDP header, and a type information of the type information of the IFP data are provided. A type information analysis unit for performing analysis; a buffer for storing the IFP data; a buffer control unit for controlling the amount of the IFP data stored in the buffer based on an analysis result of the type information analysis unit; From I
Take out the FP data and A data conversion unit for converting the data into T.30 procedure data; And a modem for modulating the 30-procedure data into a modem signal and transmitting the modulated signal to the facsimile apparatus.

[0011]

Next, a specific example of an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 2, the protocol converter according to the present invention receives an IP packet from an IP network 50 (see FIG. 1), The reception processing unit 100 converts the protocol into a protocol of 30 procedures and outputs a modulated signal to the facsimile apparatus in real time. The transmission processing unit 200 generates an IP packet by converting it into a protocol of 38 procedures and sends it out to the IP network 50. Here, since the present invention relates to the reception processing of the IP packet, the configuration of the reception processing unit 100 will be described in detail below.

The reception processing unit 100, as shown in FIG.
A header terminating unit 101 for terminating an IP header, a TCP header and a UDP header, a type information analyzing unit 102 for analyzing type information of IFP data, a buffer 104 for accumulating IFP data, and a type information analyzing unit 1
02 in the buffer 104 based on the analysis result in
Buffer controller 103 for controlling the amount of accumulated FP data
And the IFP data from the buffer 104, and
A data conversion unit 105 for converting the data into T.30 procedure data;
And a modem 106 for modulating the 30-procedure data into a modem signal and transmitting it to the facsimile apparatus.

The header terminating unit 101 performs terminating processing of an IP packet received by the protocol converter 10 (see FIG. 1) from the IP network 50, and extracts IFP data.

The type information analyzer 102 determines a high-speed signal and a control signal from the type information of the IFP data, and notifies the buffer controller 103 of the high-speed signal and the control signal.

The buffer controller 103 controls the amount of data stored in the buffer 104 with the high-speed signal and the control signal in response to the notification from the type information analyzer 102.

The buffer 104 includes a buffer control unit 103
The IFP data is stored under the control of.

The data conversion unit 105 extracts the IFP data from the buffer 104, Converted to 30 procedure data.

The modem 106 uses the T.D. The data converted into the 30-procedure data is modulated into a modem signal and transmitted to the facsimile machine.

Next, the operation of the protocol converter having the above configuration will be described with reference to FIG.

After receiving an IP packet from the IP network 50 and subjecting the IP packet to a header terminating unit 101 to terminate the header, the extracted IFP data is transmitted to a type information analyzing unit 102.
The IFP data sent and analyzed by the control signal 1
, Control signal 2 or a high-speed signal.

If the result of the analysis by the type information analyzing unit 102 is a high-speed signal, the buffer control unit 103 guarantees transmission to the facsimile apparatus even if packet reception is delayed due to fluctuations of IP packets. Is set to a shown in FIG. 4A. When the analysis result is the control signal 1, the buffer 1
04 is set to b shown in FIG. Further, in the case of the control signal 2, the accumulation amount of the buffer 104 is set to c shown in FIG.

The data converter 105 waits until the buffer 104 accumulates data up to the accumulation amount designated by the buffer controller 103, and then takes out the data. T.38 procedure data The data is converted into 30-step data, and the data is transferred to the modem 106. The modem 106 has a Modulation of the data is performed for 30 steps, and the modulated signal is transmitted to the receiving facsimile apparatus. At this time, the delay time until the data conversion unit 105 reads data changes depending on the accumulation amount of the buffer 104.

Therefore, in the present apparatus, the amount of data stored in the buffer 104 is controlled by the type of signal by analyzing the type information of the IFP data, and the delay time generated when a control signal is received is shortened.

Next, an embodiment of the protocol converter according to the present invention will be described.

According to the T.A. 30-T. 38 protocol converter 10, as shown in FIGS.
When an IP packet is received from the The reception processing unit 300 converts the protocol into a protocol of 30 procedures and outputs a modulated signal to the facsimile apparatus in real time. The transmission processing unit 400 generates an IP packet by converting it into a protocol of 38 procedures and sends it to the IP network 50. Here, since the present invention relates to the reception processing of the IP packet, the configuration of the reception processing unit 300 will be described in detail below.

The reception processing unit 300, as shown in FIG.
A header terminating unit 301 for terminating an IP header, a TCP header, and a UDP header; a type information analyzing unit 302 for analyzing type information;
Buffer control unit 303 that controls the amount of accumulated FP data
From the IFP data A data conversion unit 305 for converting the data into V.30 procedure data; 17 modem 306.

Next, the T.W. 30-T. 3
The operation of the eight protocol converter 10 will be described.

After receiving an IP packet from the IP network 50 and subjecting the IP packet to a header terminating unit 301, the extracted IFP data is transmitted to a type information analyzing unit 302.
IFP data sent is CNG, CE
D, V. Control signal 1 such as 21-preamble,
V. Control signal 2 such as V.21 channel 2; 27
ter. 29, V.I. It is determined whether the signal is a high-speed signal such as 17 or the like.

The result of the analysis by the type information analysis unit 302 is V. 17, the buffer control unit 3
At 03, the accumulation amount of the buffer 304 for guaranteeing the transmission to the facsimile apparatus even if the packet reception is delayed due to the fluctuation of the IP packet is set to 200 ms as shown in FIG. I do.

The analysis result indicates that 21-preamb
In the case of the control signal 1 of the le Flags, the packets are not continuous and the short packet
Since it is t, the accumulation amount of the buffer 304 is set to 20 ms as shown in FIG.

Further, V.I. In the case of the control signal 2 of 21 channel 2, since the packets do not continue, the accumulation amount of the buffer 304 is set to 4 as shown in FIG.
Set to 0 ms.

FIG. 11 shows an example of the buffer amount set for each type when the fluctuation amount of the IP network 50 is 200 ms.

The data conversion unit 305 waits until the buffer 304 accumulates up to the accumulation amount designated by the buffer control unit 303, and then takes out the data. T.38 procedure data 30 data, and 17 to the modem 306. V. 17 modem 306 is a T.17 modem.
Modulation of the data is performed in step 30, and the modulated signal is transmitted to the receiving facsimile apparatus.

As described above, in this embodiment, the IF
By analyzing the type information of the P data and setting the storage amount of the reception buffer, it is possible to always receive a high-speed signal.
Even if it is not set to 0 ms, 20 m for control signal 1
s, in the case of the control signal 2, control information can be received with a short delay time of 40 ms.

[0036]

As described above, according to the present invention,
It is possible to provide a protocol converter capable of preventing a response delay between facsimile apparatuses and performing stable facsimile transmission.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a facsimile communication system using an IP network to which the present invention is applied.

FIG. 2 is a diagram showing a configuration of a protocol conversion device according to the present invention.

FIG. 3 is a diagram illustrating a configuration of a reception processing unit of the protocol conversion device of FIG. 2;

FIG. 4 is a diagram illustrating an example of control of a reception buffer in a protocol conversion device.

FIG. 5 is a diagram illustrating an example of analysis of a data configuration and type information of an IP packet.

FIG. 6 is a diagram illustrating a configuration example of a conventional protocol conversion device.

FIG. 38-T. 1 is a diagram illustrating a configuration example of a facsimile communication system using a 30-protocol converter.

FIG. 8 is a configuration diagram showing one embodiment of a protocol conversion device according to the present invention.

9 is a diagram illustrating a configuration of a reception processing unit of the protocol conversion device of FIG. 8;

FIG. 10 is a diagram illustrating a control example of a reception buffer of the reception processing unit in FIG. 9;

11 is a diagram illustrating an example of type information, a type, and a reception buffer setting value of the protocol conversion device in FIG. 8;

[Explanation of symbols]

 10 protocol converter 20 protocol converter 30 T. 38 facsimile machine 40 T. 38 facsimile machine 50 IP network 60 T. 30 facsimile machine 70 T. 30 facsimile apparatus 100 reception processing unit 200 transmission processing unit 101 header termination unit 102 type information analysis unit 103 buffer control unit 104 buffer 105 data conversion unit 106 modem 300 reception processing unit 400 transmission processing unit 301 header termination unit 302 type information analysis unit 303 Buffer controller 304 buffer 305 data converter 306 17 modem 601 header termination unit 602 buffer 603 data conversion unit 604 modem

Claims (2)

[Claims] 1. Group 3 facsimile machine and ITU-
Recommendation T. 30 function to execute image data transmission and reception by executing the procedures described in ITU-T Recommendation T.30 via an Internet protocol network. A protocol conversion device having a function of transmitting and receiving image information by executing a procedure of ITU-T Recommendation T.38. A protocol conversion apparatus for analyzing type information of Internet facsimile protocol data of 38 procedures, and controlling an accumulation amount of the Internet facsimile protocol data in a buffer based on the analysis result. 2. A header terminator for terminating an IP header, a TCP header, and a UDP header; a type information analyzer for analyzing type information of the Internet facsimile protocol data; and storing the Internet facsimile protocol data. A buffer, a buffer controller that controls the amount of the Internet facsimile protocol data stored in the buffer based on the analysis result of the type information analyzer, A data conversion unit for converting the data into T.30 procedure data; 2. The protocol conversion device according to claim 1, further comprising a reception processing unit including a modem for modulating the 30-procedure data into a modem signal and transmitting the data to a facsimile apparatus.