JP2009212998A - Facsimile gateway and data transfer method in facsimile gateway - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data transfer method in a facsimile gateway which is available during a communication with no ECM and is available without expanding a buffer size, and with which dummy data can be added without picture disordering, and to provide a facsimile gateway to which the method is applied. <P>SOLUTION: In a receiving-side FAX gateway, a reception data pool section 33 accumulates picture data and when it is confirmed that an EOL, that is a code indicating a position of a line end in line data for one line, is present within the accumulated picture data, it is decided that line data for one line are accumulated. When it is decided from the confirmation of the EOL that line data for one or more lines to be transferred are accumulated, after the EOL indicating a positions of line end in line data for one line preceding to, by one line, the line data for one or more lines to be transferred, data connecting the line data for one or more lines to be transferred are transferred to a line data processing section 34 as a transfer unit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a facsimile gateway (FAX gateway) provided between an Internet Protocol (IP) network and a G3 facsimile (G3FAX), which enables FAX communication between G3FAX via the IP network, and a data transfer method in the FAX gateway. It is about.

Information and Communication Technology Committee, TTC standard standard, JT-T30, "Document Facsimile Transmission Procedure on General Exchange Telephone Network", 14.0 Edition, established on May 30, 2002 Information Technology Committee, TTC standard standard, JT-T38, "Real-time Group 3 Facsimile Communication Procedure over IP Network", Third Edition, established on April 23, 2003 JP 2004-23514 A JP 2006-121176 A

  ITU-T recommendation Non-Patent Document 1 that conforms to US Pat. No. 6,057,831 performs FAX communication by a G3 FAX apparatus in phase A (call establishment), phase B (pre-message procedure), phase C (image data transmission), phase D (end processing), and phase E. (Call disconnection) transmission procedure is specified.

  In addition, ITU-T recommendation T.I. Non-Patent Document 2 conforming to No. 38 defines a transmission procedure of FAX communication between G3 FAX apparatuses connected to an IP network via a FAX gateway. When G3 FAX communication is performed via the IP network, an analog signal from the transmission side G3 FAX apparatus is digitized by the transmission side FAX gateway and transmitted to the IP network, and digital data from the IP network is converted to analog by the reception side FAX gateway. To the receiving G3 FAX apparatus.

  ITU-T recommendation The transmission-side FAX gateway compliant with No. 38 terminates an analog FAX signal by a FAX modem unit mounted therein, converts it to digital data, and transmits it to the reception-side FAX gateway. ITU-T recommendation In phase C (image data transmission) 30, the transmission-side FAX device continues to transmit image data continuously over several tens of seconds to several minutes, and the reception-side FAX device continues within several tens of seconds to several minutes. Continue to receive image data continuously. During this time, image data is continuously transmitted in a plurality of IP packets for several tens of seconds to several minutes between the transmission-side FAX gateway and the reception-side FAX gateway. At this time, due to the occurrence of IP network load (packet loss, fluctuation, etc.), the arrival of image data to the receiving FAX gateway is delayed, and the data to be transmitted to the G3 FAX apparatus connected to the receiving FAX gateway is exhausted. May end up. In general, when data is depleted, processing such as adding dummy data or stopping generation of a FAX analog signal at the time when the data runs out is performed.

  When dummy data is added, the FAX signal from the reception-side FAX gateway is not the same as the FAX signal transmitted from the transmission-side FAX device, and the reception-side FAX device causes image corruption of received image data (for example, image Or a part of the image is generated only halfway, or the reception-side FAX apparatus detects a data abnormality and disconnects. When the reception-side FAX gateway stops generating the FAX analog signal, the reception-side FAX device detects the carrier disconnection and terminates the FAX communication abnormally.

  Further, Patent Document 1 proposes a means for avoiding data depletion by uniquely inserting a flag between error correction mode (ECM) frames as dummy data in the receiving FAX gateway.

  Furthermore, in Patent Document 2, the reception side FAX gateway lengthens the preamble signal before the image data and delays the transmission start timing of the data to the reception side FAX apparatus connected to the reception side FAX gateway. Increase the buffer size for absorbing fluctuations (preserve data that can be used to compensate for the long period when the data does not arrive), making it difficult for data to run out when the network load increases is doing.

  However, the means proposed by Patent Document 1 is ITU-T Recommendation T.30. There is a problem that it can be used only in communication using the ECM defined in the standard 30, and cannot be used in communication without ECM.

  In Patent Document 2, the buffer size is increased by extending the preamble in front of image data. 30 and ITU-T Recommendation T.30. 4 (with ECM) is defined as 1 second ± 15% and 200 ms (= allowable value + 100 ms) as short times, and there is a problem that it is not possible to cope with data depletion for a longer time.

  Therefore, the present invention has been made to solve the above-described problems of the prior art, and its purpose is a dummy that can be used during communication without ECM, can be used without increasing the buffer size, and does not cause image collapse. It is an object of the present invention to provide a data transfer method in a facsimile gateway capable of adding data and a facsimile gateway to which this method is applied.

  The facsimile gateway of the present invention receives image data from an IP network, and when one or a plurality of line data is accumulated as the image data, a reception data pool unit that transfers the accumulated image data; A line data processing unit that receives and transfers the image data transferred from the reception data pool unit; and a facsimile modem unit that converts the image data transferred from the line data processing unit into an analog facsimile signal and transmits the analog facsimile signal. When the received data pool unit confirms that EOL which is a code indicating the end position of the line data of one line exists in the stored image data, the line data of one line is accumulated. The line data of one or more lines to be transferred is accumulated by the means for judging that the data is transferred and the EOL confirmation. The line data of one or more lines to be transferred after EOL indicating the position of the end of the line data of one line before one line of the line data of one or more lines to be transferred. And a means for transferring the image data connected to the line data processing unit as a transfer unit.

  In the data transfer method in the facsimile gateway according to the present invention, when the reception data pool unit receives image data from an IP network and one or more lines of line data are stored as the image data, the stored image data is stored. And a line data processing unit receiving and transferring the image data, and a facsimile modem unit converting the image data transferred from the line data processing unit into an analog facsimile signal and transmitting the analog facsimile signal. And the step of transferring the image data by the received data pool unit confirms that an EOL which is a code indicating a position at the end of the line data of one line exists in the stored image data. A step of determining that one line of line data is accumulated, and an EOL confirmation When it is determined that the line data of one or a plurality of lines to be transferred is accumulated, the position of the end of the line data of one line one line before the line data of the one or more lines to be transferred is indicated. And a step of transferring, after EOL, the data connecting one or more lines of line data to be transferred to the line data processing unit as a transfer unit.

  According to the present invention, the reception data pool unit is configured to transfer one or more lines to be transferred after EOL indicating the position of the end of one line of line data one line before one line data to be transferred. Since the data connecting the line data is transferred to the line data processing unit as a transfer unit, even if there is a period when the network load increases and the image data is not input during image data communication, the image collapses. Dummy data generated by the line data processing unit can be easily added to the line data not to be generated. For this reason, at the time of communication without ECM, dummy data that does not cause image corruption can be added without increasing the buffer size, and it is possible to prevent the image data from being depleted.

<< 1 >> Configuration of Embodiment FIG. 1 shows a system configuration to which a FAX gateway according to an embodiment of the present invention (that is, a FAX gateway to which a data transfer method according to an embodiment of the present invention is applied) is applied. FIG. The system shown in FIG. 1 includes a G3 FAX apparatus 1, a FAX gateway 2, a FAX gateway 3, and a G3 FAX apparatus 4. The FAX gateway 2 is connected between the G3 FAX apparatus 1 and the IP network 5, and the FAX gateway 3 is connected between the G3 FAX apparatus 4 and the IP network 5. In FIG. 1, the G3 FAX apparatus 1 is a transmission side G3 FAX apparatus, the FAX gateway 2 is a transmission side FAX gateway, the FAX gateway 3 is a reception side FAX gateway, and the G3 FAX apparatus 4 is a reception side G3 FAX apparatus. It is. Both the G3 FAX apparatus 1 and the G3 FAX apparatus 4 are, for example, ITU-T recommendation T.264. This is a FAX apparatus conforming to the No. 30 standard. Further, both of the transmission-side FAX gateway 2 and the reception-side FAX gateway 3 are, for example, ITU-T recommendation T.264. It is a gateway based on 38.

  FIG. 2 is a block diagram schematically showing the configuration of the reception-side FAX gateway 3 of FIG. As shown in FIG. 2, the receiving-side FAX gateway 3 includes an IP packet processing unit 31, an ITU-T recommendation T.264, and an ITU-T recommendation T.30. 38 for executing processing of received signals in accordance with T.38. 38 reception processing unit 32, reception data pool unit 33, line data processing unit 34, FAX modem unit 35, FAX transmission signal processing unit 36, ITU-T recommendation T.38. 38 for executing transmission signal processing in accordance with T.38. 38 transmission processing unit 37.

  The IP packet processing unit 31 receives an IP packet from the IP network 5 and transmits the IP packet to the ITU-T recommendation T.264. The data is converted into data conforming to 38. T.A. 38 The reception processing unit 32 receives the data from the IP packet processing unit 31. When the received data is image data, it passes the data to the reception data pool unit 33, and when the received data is a low-speed modem command. Passes the data to the FAX modem unit 35. T. As will be described later, the 38 reception processing unit 32 also performs processing for discarding one or a plurality of message signals (MPS, EOP, EOM) indicating the end of one page of image data.

  The reception data pool unit 33 is configured to transmit the T.P. 38 receives image data from the reception processing unit 32, holds it, and transfers it to the line data processing unit 34. The reception data pool unit 33 determines that one line of line data has been accumulated when it is confirmed that EOL (End Of Line), which is a code indicating the end of line data of one line of image data, is present. When it is determined that one or more lines of line data to be transferred have been accumulated, the reception data pool unit 33 indicates the end of the line data of one line one line before the one or more lines of line data to be transferred. After EOL, the combined data of one or more lines to be transferred is transferred to the line data processing unit 34 as a transfer unit.

  FIG. 3 shows that one line before the line data (for example, L2) to be transferred when the reception data pool unit 33 determines that one line of line data (for example, L2) to be transferred has been accumulated. As a transfer unit, data (for example, E1 + L2) in which line data (for example, L2) to be transferred is combined with EOL (for example, E1) indicating the end of the line data of one line (for example, L1) FIG. 10 is a diagram for explaining a process of transferring to the line data processing unit 34; The symbol “+” in “E1 + L2” means that EOL (E1) is followed by line data (L2), and EOL (E1) and line data (L2) are treated as one transfer unit. Yes. The reception data pool unit 33 confirms that the accumulation of the line data L1 for one line is completed by the existence of EOL (E1) indicating the end of the line, and confirms that the accumulation of the line data L2 for one line is completed. It is confirmed by the presence of EOL (E2) indicating the end of the line, and it is confirmed by the presence of EOL (E3) indicating the end of the line that the accumulation of the line data L3 for one line is completed. The unit of data transferred from the reception data pool unit 33 to the line data processing unit 34 is the line of one line to be transferred after the EOL of the line data of one line one line before the line data of one line to be transferred. This is a combination of data. In the example of FIG. 3, when transferring the line data L1 of one line, data (E0 + L1) in which the line data L1 of one line to be transferred is combined with the EOL (E0) of the line data of one line before the one line. ) Is transferred as a transfer unit, and when transferring one line of line data L2, one line data EOL (E1) of the previous line is combined with one line data L2 to be transferred ( E1 + L2) is transferred as a transfer unit, and when transferring one line of line data L3, data in which one line of line data L3 to be transferred is combined with EOL (E2) of one line of previous line data (E2 + L3) is transferred as a transfer unit, and thereafter the same transfer is performed.

  FIG. 4 shows that when the received data pool unit 33 determines that the line data (for example, L1, L2, and L3) to be transferred has been accumulated, the line data (for example, L1, L1) to be transferred. Data (for example, L1, L2, L3) combined with line data (for example, L1, L2, L3) to be transferred after EOL (for example, E0) indicating the end of the line data of one line before one line of (L2, L3) , E0 + L1 + E1 + L2 + E2 + L3) is a diagram for explaining a process of transferring to the line data processing unit 34 as a transfer unit. As shown in FIG. 3, the data transfer unit to the line data processing unit 34 does not necessarily have to be one line unit. If it can be determined that a predetermined number of lines of line data are stored, the storage is completed. The line data of a plurality of lines may be transferred together. In the example of FIG. 4, the reception data pool unit 33 indicates that the accumulation of line data of a plurality of lines (for example, line data L1, L2, and L3 of three lines) has been completed, EOL indicating the end of the line (for example, E1) , E2, E3). The unit of data transferred from the reception data pool unit 33 to the line data processing unit 34 is transferred after EOL (for example, E0) of the line data of one line before the line data of the plurality of lines to be transferred. This is data (for example, E0 + L1 + E1 + L2 + E2 + L3) combined with data of a predetermined number of lines. Note that the line data L4 in FIG. 4 is being received (indicated by symbol M in FIG. 4), and the data is not ready in the received data pool unit 33 (accumulation of the line data L4 has not been completed). When the line data L1, L2, L3 of a plurality of lines are transferred, they are not transferred. Also, the number of lines to be transferred is not limited to three lines.

The line data processing unit 34 shown in FIG. 2 adjusts the image data transferred from the reception data pool unit 33 and stored in the line data processing unit 34 to the transmission speed of the FAX modem unit 35, and at any time, the FAX modem unit. 35. If there is no data in the line data processing unit 34 at the timing of passing data to the FAX modem unit 35 (depletion), the line data processing unit 34 uses ITU-T recommendation T.264 as dummy data. Fill (0 variable-length signal sequence), which is dummy data defined in 4, is generated and passed to the FAX modem unit 35. The line data processing unit 34 transfers data from the received data pool unit 33 to the line data processing unit 34 until data depletion in the line data processing unit 34 is resolved, or until a predetermined upper limit time elapses. , Continue to generate Fill. In the present embodiment, the Fill can be generated for each page of FAX image data, for example, by an amount corresponding to a maximum of 2.5 seconds. When the upper limit value of 2.5 seconds is exceeded, the FAX gateway 3 stops data transmission. If the FAX modem unit 35 is communicating at 14400 bps, the data for one page of FAX image data is
14400 bits x 2.5 seconds = 36000 bits
It is data of. However, the upper limit of the fill generation time is not limited to 2.5 seconds.

  When the line generation processing by the line data processing unit 34 occurs, the line data processing unit 34 displays the generation information of the fill generation processing as T.D. 38 notification to the reception processing unit 32. T. 38 When the reception processing unit 32 receives the generation information of the fill generation processing from the line data processing unit 34, the reception processing unit 32 discards one or a plurality of message signals indicating the end of one page of the image data received thereafter. Processing may be performed to clear the information of the fill generation process received from the line data processing unit 34 (detailed in the description of FIGS. 6 and 7). The process of discarding one or a plurality of message signals indicating the end of FAX image data is a process of discarding the first MPS, EOP, EOM after receiving the generation information of the Fill generation process, or a plurality of times from the beginning ( For example, the first and second) MPS, EOP, and EOM can be discarded.

  The FAX modem unit 35 includes a line data processing unit 34 or a T.D. 38 The data delivered from the reception processing unit 32 is converted into a FAX analog signal and transmitted. The FAX modem unit 35 passes the received FAX analog signal to the FAX transmission signal processing unit 36 as transmission data.

  The FAX transmission signal processing unit 36 converts the data passed from the FAX modem unit 35 to T.264. 38 to the transmission processing unit 37. T.A. The transmission processing unit 37 converts the data transmitted from the FAX transmission signal processing unit 36 to ITU-T recommendation T.38. The data is transferred to the IP packet processing unit 31 as data compliant with the standard 38. The IP packet processing unit 31 converts the received data into an IP packet and transmits it to the IP network 5.

<< 2 >> Operation of Embodiment FIG. 5 is an example of FAX communication of a system including a reception-side FAX gateway 3 according to an embodiment of the present invention (in the case of normal communication and communication in which a Fill needs to be added). FIG. The symbol in the figure is the ITU-T recommendation T.30. CNG is a calling tone, CED is a called station identification signal, NSF is a non-standard function, CSI is a called terminal identification signal, DIS is a digital identification signal, and TSI is a transmitting terminal identification signal. , DCS is a digital command signal, TCF is a training check signal, CFR is a reception preparation confirmation signal, MPS is a multipage signal, EOP is a procedure end signal, MCF is a message confirmation signal, and DCN is a disconnection command.

  As shown in part 6 of FIG. 5, in normal communication, an IP packet received from the transmission-side FAX gateway 2 is received by the IP packet processing unit 31 of the reception-side FAX gateway 3, and the ITU-T recommendation T.264 is received. 38, data conforming to T.38. 38 to the reception processing unit 32. T.A. When the received data is a low-speed modem command, the 38 reception processing unit 32 transfers the data to the FAX modem unit 35, and the FAX modem unit 35 transmits the data to the receiving side G3 FAX apparatus 4 as a FAX analog signal. T. 38 When the received data is image data, the reception processing unit 32 transfers the data to the reception data pool unit 33. As soon as it is determined in the received data pool section 33 that one line of line data is available, it is determined that the accumulation of one line of line data is completed in the EOL indicating the end of the line data of the previous line. The transferred data (for example, EOL (E0) in FIG. 3 and line data L1 following this) is transferred to the line data processing unit 34. The confirmation that the accumulation of the line data of one line is completed is performed by confirming that the EOL indicating the position of the end of the line data of the accumulated one line exists in the reception data pool unit 33. . For example, this is performed by confirming that EOL (E1) after line data L1 in FIG. 3 exists.

  The operation when data depletion occurs in the line data processing unit 34 due to packet loss or the like is shown in a part 7 of FIG. When packet loss (reference numeral 50 in FIG. 5) or the like occurs in data transfer from the transmission FAX gateway 2 to the reception FAX gateway 3 and data reception is delayed (reference numeral 51 in FIG. 5), a reception data pool section The arrival of data at 33 is delayed, and it takes a long time to complete the accumulation of one line of line data. In the meantime, the data in the line data processing unit 34 is sequentially transferred to the FAX modem unit 35, and all the data in the line data processing unit 34 may be lost (depleted) as time elapses (FIG. 5 of 52). At this time, the line data processing unit 34 uses ITU-T recommendation T.30 as dummy data. Fill, which is dummy data defined in 4, is generated and transferred to the FAX modem unit 35 (reference numeral 53 in FIG. 5). This operation is performed until new image data arrives at the reception data pool unit 33, accumulation of one or more lines of line data is completed, and the line data is transferred to the line data processing unit 34, or a predetermined upper limit. Continue until time passes. The line data processing unit 34 transfers data from the reception data pool unit 33 by using, as a transfer unit, data composed of a combination of EOL of the previous line data and one or more lines of line data to be transferred. At this point, the fill generation process is stopped and the normal operation is resumed. In FIG. 5, reference numeral 54 indicates that image data reception time is increased by adding Fill (for example, a maximum of 2.5 seconds per page of image data). Further, in FIG. 5, reference numeral 55 denotes a process of discarding the MPS when Fill is added (details are described in FIG. 6). In FIG. 5, reference numeral 56 indicates that the transmission time of image data for one page is 3 seconds.

  FIG. 6 shows a process (reference numeral 63) for recovering the timing shift (reference numerals 61 and 62) caused by the fill generation process (reference numeral 60) by the line data processing unit 34 of the reception side FAX gateway 3 according to the embodiment of the present invention. ) Is a sequence diagram for explaining (when a Fill of 2.5 seconds or less is added and EOP is discarded). Here, the upper limit of the amount of fill generated by the line data processing unit 34 is set to 2.5 seconds per page of image data transmitted by FAX. Further, when the line data processing unit 34 executes the fill generation process, the line data processing unit 34 receives the T.P. 38 The generation information of the fill generation process is notified to the reception processing unit 32. T.A. 38. When receiving the generation information of the fill generation processing, the 38 reception processing unit 32 receives the received MPS, EOP during the first (first) MPS, EOP, EOM processing received after one page of image data. The EOM is discarded (reference numeral 63 in FIG. 6), and the transfer to the FAX modem 35 is not performed. Then, transfer processing from the retransmitted MPS, EOP, and EOM (reference numeral 64 in FIG. 6) to the FAX modem unit 35 is performed. After EOP (retransmission), the image data reception time becomes longer due to the addition of the Fill due to the influence of the Fill generation process (reference numeral 61 in FIG. 6), and as a result, the shifted timing (reference numeral 62 in FIG. 6). However, the timing becomes normal (reference numeral 65 in FIG. 6), and the timing shift can be recovered.

  FIG. 7 does not perform processing for recovering the timing shift (reference numerals 71 and 72) caused by the fill generation process (reference numeral 70) by the line data processing unit 34 of the reception-side FAX gateway 3 according to the embodiment of the present invention. It is a sequence diagram for demonstrating the case (code | symbol 73) (When the Fill of 2.5 seconds or less is added and EOP is not discarded). Here, the upper limit of the amount of fill generated by the line data processing unit 34 is set to 2.5 seconds per page of image data transmitted by FAX. In the sequence shown in FIG. 7, unlike the case of FIG. 6, even if the line data processing unit 34 executes the fill generation process, the first (first) received after the image data for one page is received. Do not discard EOP. In the example shown in FIG. 7, the timing at which EOP arrives at the receiving side G3 FAX apparatus 4 (reference numeral 74) is inherently later than the timing at which EOP arrives at the receiving side G3 FAX apparatus 4 (reference numeral 75). Reference numeral 76) is also transmitted from the transmission side FAX gateway 2 with a delay. At this time, depending on the delay state of the MCF, there is a possibility that the MCF is transmitted from the transmission FAX gateway 2 at the same time as the EOP (retransmission) time (reference numeral 77). In this case, a message collision (symbol 78) may occur between the transmission side G3 FAX apparatus 1 and the transmission side FAX gateway 2. This phenomenon is caused by the reception side G3 FAX apparatus 4 returning a response to the first EOP of the image data whose timing is shifted. For this reason, as shown in FIG. 6, it is preferable to adopt a measure not to transmit the EOP of the image data whose timing is shifted to the receiving side G3 FAX apparatus 4, and by adopting the configuration as shown in FIG. It is possible to avoid the occurrence of the problem of collision (reference numeral 78).

  FIG. 8 is a sequence for explaining the operation when there is a large amount of Fill in the receiving FAX gateway 3 to which the data transfer method according to the embodiment of the present invention is applied (when a Fill exceeding 3 seconds is added). FIG. Hereinafter, the reason why it is desirable to set the amount of Fill added by the Fill generation process by the line data processing unit 34 of the FAX gateway 3 to 2.5 seconds or less per page will be described with reference to FIG. The sequence shown in FIG. 8 shows a case where a fill generation process of 3 seconds or more is executed without adopting the time limit (2.5 seconds) of the fill generation process (reference numeral 80). In FIG. 8, since the transmission time of the image data is extended, the time when the first EOP arrives at the receiving FAX gateway 3 is delayed (reference numerals 81 and 82), and the response is made within 3 seconds (reference numeral 83) which is the retransmission interval. I won't come back. In this case, since transmission of the EOP (reference numerals 81 and 82) of the previous image data is not completed at the timing when the transmission FAX gateway 2 originally transmits EOP (retransmission) (reference numeral 84), real time Cannot be sent to the network, causing a delay. That is, as shown in FIG. 8, since the image data transmission time has increased by 3 seconds or more, the EOP (retransmission) transmission timing is also delayed in the transmission-side FAX gateway 2 (reference numerals 84 and 85). For this reason, in order to recover the timing by EOP (retransmission) (symbol 84) and not cause message passing and collision thereafter, it is desirable to set the amount of Fill to be 3 seconds or less, and other delay margins. In consideration of the above, it is more desirable to set the upper limit to 2.5 seconds.

  Although FIGS. 6 to 8 illustrate EOP discard as an example, similar discard processing can be applied to MPS or EOM.

Further, in the description of the present embodiment, the first (first) EOP after image data transmission is discarded, but even if EOP (retransmission) is lost, the subsequent EOP (retransmission 2) If the system wants to give priority to increasing the upper limit of the added amount of Fill, a plurality of times after the image data transmission (for example, the second time). EOP) may be discarded, and the limit of fill generation processing is a maximum of 5.5 seconds per page = (3 seconds × 2) − (margin 0.5 seconds) = 6 seconds−0 However, in ITU-T recommendation T.4, the maximum number of fills that can be continuously generated is 5 seconds.

<< 3 >> Effects of the Embodiment According to the embodiment of the present invention, a delay occurs in the arrival of image data to the receiving FAX gateway 3 due to load fluctuations or packet loss in the IP network 5, and the receiving FAX gateway 3. Even if the line data processing unit 34 is depleted of data, if the line data processing unit 34 generates a Fill and outputs it to the FAX modem unit 35 (Fill is added), the FAX modem unit 35 receives the carrier. Can be avoided.

  In addition, according to the embodiment of the present invention, the data transfer from the reception data pool unit 33 to the line data processing unit 34 is performed with respect to the line data of one line before one line of one or more line data to be transferred. Since EOL indicating the position of the end of the line is followed by transfer using image data connecting one or more lines of line data to be transferred as a transfer unit, the Fill generated and output by the line data processing unit 34 is always , Line data is inserted between line data (for example, L1 in FIG. 3) and EOL (for example, E1 in FIG. 3) indicating the end of the line. Therefore, it is possible to reliably transmit the image data from the FAX gateway 3 to the receiving side G3 FAX apparatus 4 without destroying the image data.

  Further, according to the embodiment of the present invention, the dummy data generated by the line data processing unit 34 is always inserted into the line data break during the image data communication period. Can be extended. For this reason, there is no need for buffering before image data transmission in the receiving FAX gateway 3, and real-time performance can be increased.

  Furthermore, according to the embodiment of the present invention, the upper limit of Fill insertion is provided, and the first or first and second MPS, EOP, and EOM discarding processes are executed at the receiving FAX gateway 3. Thus, it is possible to recover the timing difference between the transmission side and the reception side caused by the Fill insertion, and it is possible to avoid a post message collision after the image data.

  Furthermore, according to the embodiment of the present invention, the line data processing unit 34 displays the occurrence information of the fill generation process in the T.264 format. 38 Since the reception processing unit 32 is notified, it is determined that it is not necessary to discard post messages (EOL, MPS, EOM) after the image data, and the processing is changed so as not to cause unnecessary retransmission processing. be able to.

  Further, according to the embodiment of the present invention, the above effect can be obtained only by the reception-side FAX gateway 3, so that it is not necessary to provide a special means for the transmission-side FAX gateway 2. Therefore, the above effects can be obtained regardless of the communication partner model.

It is a figure which shows schematically the structure of the system containing the FAX gateway which concerns on embodiment of this invention. FIG. 2 is a block diagram schematically illustrating a configuration of a reception-side FAX gateway in FIG. 1. The reception data pool unit in FIG. 2 uses, as a transfer unit, data obtained by connecting the line data of one line to be transferred after EOL indicating the position of the end of the line data of one line before the line data of one line to be transferred. FIG. 5 is a diagram for explaining a process of transferring to a line data processing unit. The reception data pool unit of FIG. 2 uses, as a transfer unit, data obtained by connecting the line data of a plurality of lines to be transferred after the EOL indicating the position of the end of the line data one line before the line data of the plurality of lines to be transferred. FIG. 5 is a diagram for explaining a process of transferring to a line data processing unit. It is a sequence diagram which shows the example (in the case of normal communication and the communication which needs to add Fill) of the FAX communication of the system containing the receiving side FAX gateway which concerns on embodiment of this invention. Processing for recovering the timing shift caused by the fill generation processing by the line data processing unit of the receiving FAX gateway according to the embodiment of the present invention (when adding a fill of 2.5 seconds or less and discarding EOP) It is a sequence diagram for demonstrating. When the processing for recovering the timing shift caused by the fill generation processing by the line data processing unit of the receiving FAX gateway according to the embodiment of the present invention is not performed (Fill of 2.5 seconds or less is added and EOP is discarded) It is a sequence diagram for demonstrating (when not doing). FIG. 10 is a sequence diagram for explaining the operation when the amount of added Fil is large in the receiving-side FAX gateway to which the data transfer method according to the embodiment of the present invention is applied (when a Fill exceeding 3 seconds is added).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission side G3 FAX apparatus, 2 Transmission side FAX gateway, 3 Reception side FAX gateway, 4 Reception side G3 FAX apparatus, 5 IP network, 31 IP packet processing part, 32 T. 38 reception processing section, 33 reception data pool section, 34 line data processing section, 35 FAX modem section, 36 FAX transmission signal processing section, 37 T. 38 transmission processing unit.

Claims (8)

A reception data pool unit that receives image data from an IP network and transfers the stored image data when line data of one or a plurality of lines is stored as the image data;
A line data processing unit that receives and transfers the image data transferred from the reception data pool unit;
A facsimile gateway having a facsimile modem unit for converting the image data transferred from the line data processing unit into an analog facsimile signal and transmitting the analog facsimile signal;
The received data pool unit is
Means for determining that one line of line data is accumulated when it is confirmed that EOL which is a code indicating the position of the end of one line of line data exists in the accumulated image data;
When it is determined by EOL confirmation that one or more lines of line data to be transferred are accumulated, the end of the line data of one line one line before the one or more lines of line data to be transferred A facsimile gateway comprising: an EOL indicating a position; and means for transferring the image data obtained by connecting the line data of one or a plurality of lines to be transferred to the line data processing unit as a transfer unit.   The line data processing unit generates dummy data when there is no image data to be transferred in the line data processing unit at the timing of transferring the image data to the facsimile modem unit, and the generated dummy data is stored in the line data processing unit. 2. The facsimile gateway according to claim 1, further comprising means for transferring to the facsimile modem unit.   When the line data processing unit is generating the dummy data, when the image data is received from the reception data pool unit, or the generation of the dummy data is started, a predetermined upper limit time is set. 3. The facsimile gateway according to claim 2, further comprising means for stopping generation of the dummy data when the time has elapsed. A reception processing unit for processing the image data from the IP network and transferring it to the reception data pool unit;
The line data processing unit has means for sending dummy data generation information indicating that the dummy data is generated to the reception processing unit when the dummy data generation processing occurs,
The reception processing unit that has received the dummy data generation information receives first or a plurality of message signals that indicate the end of one page of image data, or the first or a plurality of message signals that are received first and the second and subsequent times. 4. The facsimile gateway according to claim 2, further comprising means for discarding one or a plurality of message signals to be received and transferring image data from which the message signals have been discarded to the reception data pool unit. 5. A reception data pool unit that receives image data from an IP network and transfers the stored image data when one or more lines of line data are stored as the image data;
A line data processing unit receiving and transferring the image data;
A facsimile modem unit comprising: converting the image data transferred from the line data processing unit into an analog facsimile signal and transmitting the analog facsimile signal;
The step in which the received data pool unit transfers image data includes:
Determining that the line data of one line is accumulated when it is confirmed that EOL which is a code indicating the position of the end of the line data of one line exists in the accumulated image data;
When it is determined by EOL confirmation that one or more lines of line data to be transferred are accumulated, the end of the line data of one line one line before the one or more lines of line data to be transferred A data transfer method in a facsimile gateway, comprising: a step of transferring the data connecting one or more lines to be transferred to the line data processing unit after the EOL indicating the position as a transfer unit. .   When there is no image data to be transferred in the line data processing unit at the timing of transferring image data to the facsimile modem unit, the line data processing unit generates dummy data, and the generated dummy data is stored in the line data processing unit. 6. The data transfer method in a facsimile gateway according to claim 5, further comprising a step of transferring to the facsimile modem unit.   In the line data processing unit, when the dummy data is generated, when image data is received from the reception data pool unit, or after the generation of the dummy data is started, a predetermined upper limit time is set. 7. The data transfer method in a facsimile gateway according to claim 6, further comprising a step of stopping the generation of the dummy data when the time has elapsed. Sending the dummy data generation information indicating that the line data processing unit is generating the dummy data to the reception processing unit when the dummy data generation processing occurs;
The reception processing unit that has received the dummy data generation information receives one or more message signals that represent the end of one page of image data, or one or more message signals that are received first, and the second and subsequent times. The method includes: discarding one or more message signals to be received, and transferring image data from which the one or more message signals have been discarded to the reception data pool unit. Data transfer method in a facsimile gateway.

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