JPH04129352A - Electronic mail system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic mail system comprising a plurality of mail communication terminals and a center device having a mail storage and exchange function.

[Prior Art] In recent years, systems for digitizing mail, which was traditionally delivered manually, have become popular for the purpose of reducing office expenses and improving timeliness.

In particular, in a system in which each communication terminal transfers messages via a center device having a storage and forwarding function, immediate delivery, one time delivery, and confidential delivery are available.

A wide variety of email services such as mailboxes and bulletin boards are provided.

Among these services, in the instant delivery, time-specified delivery, and broadcast mail services, if storage and forwarding is not performed, when the other party's terminal is busy and the message is sent, the other party's terminal enters a busy dialing operation. A situation occurred where it was not possible to send data until it was released. Furthermore, when sending multiple images, if the other party's terminal does not have a large-capacity buffer memory, there is an inconvenience in that the recipient has to wait until all images are output.

However, a mail service having a store-and-forward function does not have the above-mentioned troubles, and has the advantage of being able to finish the sending operation and move on to the next operation without being limited by the conditions of the other party's terminal. Also, if you put mail in a mail box owned by the other person, such as a confidential or mailbox, you can retrieve mail from your own mail box whenever necessary from any terminal connected to the system, regardless of location. Is possible. In particular, with confidential emails, you cannot withdraw them without entering your PIN, so the emails are delivered only to specific people and can be kept confidential.

In addition, bulletin board services provide unique services for store-and-forward message communication, such as the ability to provide messages to an unspecified number of people. Furthermore, if the other party's terminal becomes unable to send mail, there is a function to send mail to a substitute terminal for that terminal, and if there is no substitute terminal or it is not possible to send mail to a substitute terminal, the center device will not be able to send mail until the terminal becomes ready to receive. It is also possible to have a function that allows mail to be temporarily stored (hereinafter referred to as center storage) and retrieved from another terminal.

[Problems to be Solved by the Invention] However, in the conventional system described above, when the mail communication terminal sends a message to the center device, control information regarding the message (e.g., calling/receiving terminal number, mail service content, etc.) information necessary to receive)
and the message body are sent all at once, so even if the center device discovers an error in the information, there is no way to notify the center of the error, and the sent message is wasted.
The sender is notified that the message was not delivered only when the non-delivery notification for the message is returned to the sender terminal, so there is a problem in that the report is delayed.

The present invention was made to solve the above problems, and
To provide an e-mail system in which a sender can immediately recognize errors in e-mail control information and can suppress sending of unnecessary messages as much as possible.

[Means and operations for solving the problems] In order to achieve the above objects, the e-mail system of the present invention has the following configuration. That is, in an e-mail system consisting of a plurality of e-mail communication terminals and a center device having an e-mail storage and exchange function, a discriminating means for discriminating whether mail control information received from the e-mail communication terminals is correct, and a discriminating result by the discriminating means are provided. The mail communication terminal includes a transmitting means for transmitting data to the mail communication terminal, and a communication control means for controlling communication according to the determination result transmitted by the transmitting means.

Preferably, one aspect of the transmission means is to transmit the message at the boundary between the messages received for each page.

Furthermore, preferably, one aspect of the communication control means is such that if the determination result is correct, the communication is continued, and if the determination result is incorrect, the communication is stopped.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Description of Configuration (Figs. 1 and 2)> Fig. 1 is a system configuration diagram of the e-mail system in this embodiment. In the figure, 1 to 4 are equipped with applications that can send and receive e-mail, text data,
This includes email communication terminals that can handle image data and other media data, such as telematic terminals. 5 is a center device that has various management functions such as storage and exchange of e-mails, terminals or personal In, and provides various e-mail services to each e-mail communication terminal;
6 is a network that allows each of the mail communication terminals 1 to 4 and the center device 5 to communicate with each other. Network 6 includes PSTN (telephone network) and PSPDN if it is a wide area network.
(packet switched network).

There are PSCDN (circuit switched networks), leased lines, etc., and in the case of in-house networks, there are local area networks, PBXs, and in-house leased lines. Reference numeral 7 designates a central processing unit that controls all the devices in the center device 5. Reference numeral 8 designates a main storage device that temporarily stores mail control information and mail body information, stores various management tables, or is used as a work area. 9 is a large-capacity storage device used as a backup for a large amount of e-mails, mailboxes, various information, or programs, and its storage media include optical disks, magnetic disks,
Examples include magneto-optical disks and magnetic tape.

Reference numeral 10 indicates a program storage device in which control programs necessary to operate the system and application programs having email functions are stored; reference numeral 11 indicates human power devices such as consoles and printers used for system management, power supply monitoring, etc. It is a peripheral device including a power supply device such as a backup power supply. 12 is a communication control device that controls communication with each mail communication terminal 1 to 4, and is connected to the network 6 described above.
It performs interface matching with the terminals, link control to establish connections with each terminal 1 to 4, network control to receive and receive data and secure communication channels, etc.

FIG. 2 is a diagram showing the internal configuration of the mail communication terminal in this embodiment.

In the figure, 13 is a central processing unit that controls the entire system of mail communication terminals, 14 is a main storage unit that stores control programs and processing programs for mail-like functions necessary for system operation, and is used as a work area; 15 is a large-capacity storage device that stores media data handled by this terminal, and stores information about the body of the email. 16 is a control unit that outputs media data handled by this terminal, and CR
Display on screen such as T or LCD 1 Display on paper or photosensitive paper 8
In the case of power and audio data, there is a function using a speaker. 17 is an input unit for inputting media data handled by this terminal, and is a keyboard.

Touch sensor, digitizer, photoreceptor, image sensor (CO
D, image pickup tube, etc.), in the case of audio data,
There is input via microphone. Reference numeral 18 denotes a communication control device that controls communication with the center device 5 via the network 6, and performs interface matching with the network 6 described above, link control to establish a connection with the center device 5, data transmission/reception, and securing a communication path. Performs network control, etc.

Next, in the system configuration shown in FIG.
When the user 4 requests a mail service from the center device 5, it is necessary to exchange not only the main text of the mail but also control information for the mail instructing how to process the mail.

<Explanation of control information (Fig. 3)> Here, Fig. 3 is a diagram showing an example thereof, and for convenience of explanation, explanation will be given along this example, but the format and contents are limited to this. isn't it.

As illustrated, the mail service identifier 30 indicates the content of the service. For example, services such as instant delivery, inserting/withdrawing mailboxes, inserting/withdrawing mailboxes, bulletin boards, and various make-shift requests have information encoded so that they can be identified between terminals and center equipment. be. Similarly, the mail service additional information 31 includes, for example, even if the mail service identifier is immediate delivery, the priority of the mail, simultaneous delivery in the case of multiple recipients, time specification, presence or absence of delivery confirmation, proxy terminal information, etc. This is information for specifying the presence or absence, etc., as necessary. The mail sender information 32 includes information such as the sender's name, affiliation, and sender terminal name, which is necessary for the recipient to identify the sender. The mail sending time 33 is for notifying the recipient of the time when the mail was sent. If the receiving terminal is unable to deliver from the center equipment due to a malfunction and the data is held at the center, or if the recipient needs to access and retrieve the information such as a mailbox or confidential box, this information can be used to determine when the transmission was sent. You can tell if it's an email.

Next, the mail recipient information 34 is necessary information when the center device specifies the delivery destination when delivering the mail, and is also important information to ensure that it is passed to the recipient even after the mail is delivered. . The mail delivery time 35 is used to inform the recipient of the time when the mail was received, but even if the center device delivers the mail to the designated receiving terminal, it is not actually delivered to the recipient. This information is necessary because there is a delay before the information is available. Also, as for the information in the email body, first of all,
The subject of the e-mail36, the amount of information in the e-mail body (in the case of e-mail communication terminals, it may be expressed in pages), the type of media (broadly divided into image data, text data, audio data, etc.) Among them, G
3 facsimile, MH code such as G4 facsimile, M
There is also a classification based on encoding methods for data compression such as R code and MMR code. ) The email control information shown in FIG. 3 mentioned above is hereinafter referred to as a control document (CD).

The mail body for this CD is called a normal document (ND).

<Explanation of communication format (Figure 4)> Next, when performing email communication between the terminal and the center device, the format shown in Figure 4 (a)
It is formatted and sent out as shown in ~(c). This is a format used in HDLC communication procedures, and F2O is called a flag and is used to identify the beginning and end of this data. The data is '01111110', and in order to prevent this pattern from occurring except for flags, insertion and deletion of '0°' are performed to maintain data transparency. Next, A41 is an address, but it is not the address of the sending party, but is used to identify the following when sending and receiving data between the network and the terminal device (or center device). ing.

When A="11000000", A="100000" is sent as a command or response from the DCE to the DTE.
00'', it is used as a command or response from the DTE to the DCE.Next, C42 is a controller section, and ■ (information) frame (DATA), S
(Monitoring) frame (RR, RNR, REJ), U
(Non-block Shari) Frame (SABM, UA, DM, DIS
C.

FRMR) is used to identify each frame. There is a P/F bit in this, and if the P bit (ball) is set to "1", it is necessary to set the F bit (final) to "1" and return it.

When transmitting and receiving data between the terminal and the center device, the communication control unit 43 negotiates data format specifications and media type during call setup/cancellation and data transfer between the terminal and the center device. In addition, an identifier is inserted to perform controls such as confirmation of reception for each data transfer unit such as page or block, and request for retransmission of data in the event of an error.

This control content and procedure is determined by CCITT and ISO.
Standardization is underway. O31, (Open Sys
This corresponds to the 3rd layer (network layer), 4th layer (transport layer), and 5th layer (session layer) of the 7-layer model of the communication protocol of TMsInterconnection.

The network layer performs this setting/cancellation, the transport layer performs network quality checks and settings via other networks, and the session layer performs data transfer type negotiation and confirmation/retransmission of data transfer in units of pages and blocks. Related controls are specified. Next, the FCS 45 is a frame check sequence and has a function of checking whether data is correct or incorrect. However, since there is no correction function, if there is an error, a retransmission request is made and the data is retransmitted.

Next, the user data section 44 is used when the terminal side (user side) rather than the network sends data to the other party's terminal (other user). Alternatively, it is also used by the network to provide optional additional services to users. The service may include, for example, an extended address,
There are extension addresses, etc. FIG. 4(b) shows a communication data format when transmitting a CD. Then, the CD which is the mail control information shown in FIG. 3 is inserted into the user data section 44. Moreover, FIG. 4(C) shows the communication data format when transmitting ND. Similarly, ND, which is the information of the mail body, is inserted into the user data section 44.

<Description of Communication Procedure (FIGS. 5 to 7)> Next, FIG. 5 is a diagram showing a data communication procedure related to network control between each of the terminals 1 to 4 and the center device 5. As shown in the figure, when a terminal accesses a center device to transfer data, the terminal first requests the network to make a call, and the network outputs an incoming call to the center device. The center device receives this incoming call and returns an incoming call acceptance message to the network, and the network receives this and returns a connection completion message to the terminal. Through this process, a call is established between the terminal and the center device, and data transfer becomes possible. Thereafter, when data transfer is finished, the terminal issues a recovery request to the network, and the network outputs a disconnection instruction to the center device. The center device receives this disconnection instruction and returns a disconnection confirmation to the network, and the network receives this and returns a restoration confirmation to the terminal.

Next, FIG. 6 is a diagram showing a data communication procedure during data transfer after a call is established. First, as shown in Figure 5, when a call is established and data communication becomes possible between the terminal and the center equipment, the type of the other party's terminal is confirmed as shown in Figure 6.
Establish a session connection to confirm the data exchange conditions.

When a session connection is sent from the terminal to the center device,
Upon receiving this, a confirmation is returned from the center device to the terminal. Then, by sending the CD (control document) and ND (normal document), a request for mail service is made from the terminal to the center device, and in response to the request, the center device returns acceptance of the service. Here, if there is no data to be continuously transferred from the terminal side or if there is no data to be transferred from the center device, a session disconnection message is sent to the center device to cancel the session connection. In response to this, the center device returns completion, and through this series of communication procedures, the request and reception of the mail service from the terminal to the center device and the transfer of the mail body are completed. When the data transfer shown in Fig. 5 is completed, the above-mentioned recovery request, disconnection instruction, disconnection confirmation, and recovery confirmation are respectively sent to cancel the call established between the terminal and the center device, and the call is disconnected. . On the other hand, the center device decodes the sent CD and executes the service in response to the service request. For example, in the case of instant distribution shown in FIG. 6, the center device directs the sending terminal to the destination terminal specified by the
The call setting shown in FIG. 5 is performed, and when the call is established, a session connection is executed.

Then, after transmitting the CD and the ND which is the body of the received mail, and receiving an acceptance for the CD and ND from the destination terminal, the session is disconnected and the call disconnection procedure is executed. In this way, the instant delivery mail service requested by the originating terminal is completed.

In the following, descriptions of call setup/disconnection, session connection/disconnection, CD/ND reception, etc. will be omitted since they are the same.

Furthermore, if there is an instruction from the originating terminal to confirm delivery as an additional service for immediate delivery, as shown in Figure 6, the center device sends an e-mail to the originating terminal after the e-mail has been sent to the receiving terminal. Return confirmation of delivery as CD.

FIG. 7 shows a data communication procedure during data transfer in the mailbox service. When the originating terminal makes a mailbox request to the center device using a CD and sends an ND, the center device receives this and posts this ND to the designated mailbox. When the mailbox catalog inquiry CD is accessed from the destination terminal, the center device transmits the CD including the list in the supplementary information 39 of FIG. 3 to the destination terminal. Furthermore, if there is a request from the destination terminal to compare mail in the mailbox using a CD, the mail is sent to the destination terminal. and,
Mailbox service completes.

<Description of Management Tables (FIG. 8)> Next, various management tables defined within the center device will be described.

FIGS. 8(a) to 8(e) show typical management tables in this embodiment. and Fig. 8(a) and (b)
) are attribute management tables, and FIGS. 8(C) to (e)
is the mail management table. This Figure 8(a) is
This is a terminal management table in which information about all terminals connected to the center device is managed. When running the mail service, this table is always referenced.
It is possible to confirm the sender and recipient, confirm device information, and send on behalf of the sender. FIG. 8(b) is a user management table in which the personal identification number used when making a withdrawal from a confidential mailbox, the terminal to which the person belongs, or the personal ID, etc. are managed. It also enables security and email communication between people, rather than machine-to-machine.

Further, FIG. 8(C) is a mailbox management table, in which control information of mails posted in each mailbox, memory space of storage location, etc. are managed. This table is then referenced when inquiring about the mailbox list or registering/withdrawing a mailbox. FIG. 8(d) is a management table for confidential boxes, in which the same contents as mailboxes are managed for each confidential box. Note that this confidential email can only be withdrawn by the person in question using his or her personal identification number.

For this reason, the password is also managed in this table.

Fig. 8(e) shows a function that stores the mail in the center device so that when the mail cannot be sent to the destination terminal, it can be sent after waiting for the terminal to recover, or it can be retrieved from another terminal. This table is required when the data center has a management table, and is called the center storage management table. In this case, unlike mailboxes and confidential boxes, the above-mentioned boxes are not prepared, and management is performed on a per-mail or per-terminal basis. Other than that, it is the same as FIG. 8(C),
It is referenced when inquiring about the center custody list or withdrawing center custody mail.

Next, the operation of the center device in this embodiment will be explained below according to the flowchart shown in FIG.

First, it waits for an access from the originating terminal, and if there is an access, it stores the CD sent and decrypts the CD. This is a process of checking with reference to the management table shown in FIGS. 8(a) to 8(e) mentioned above to determine whether there are any errors or deficiencies in the information content of the CD. Thereafter, when the CD is ready to be sent to the originating terminal, the CD containing the above-mentioned check result, ie, the correct/incorrect determination result, is sent.

Here, if the contents of the sent CD are correct, it is determined whether or not there is an ND sent successively from the originating terminal, and if there is an ND, that ND is stored. Then, a mail service corresponding to the contents of the sent CD is executed for this ND.

On the other hand, if there are any errors or omissions in the contents of the CD sent to you,
Waits for a disconnection instruction from the calling terminal, and when the disconnection instruction is received,
Sends a disconnection confirmation to the originating terminal and ends the communication.

FIG. 10 is a diagram showing a data transfer procedure in the operation shown in FIG. 8. In the figure, Figure 10 (a) and (b)
) is the case when the CD is correct, and Figure 10 (C) is the case when the CD is correct.
is incorrect.

First, in FIG. 10(a), from the originating terminal to the center device,
D■ is transmitted, then a session reversal command is transmitted, and the center device becomes capable of CD transmission. Therefore, the center device transmits CD■ which notifies the result of determining whether CD■ is correct or incorrect to the originating terminal, and conversely transmits a session reversal command, so that the originating terminal becomes ready to transmit data again. As a result, the originating terminal recognizes that CD ■ is correct, and subsequently transmits ND to the center device and ends the communication.

In addition, in FIG. 10(b), only when the determination result of CD■ is correct in response to the session reversal command from the originating terminal, instead of notifying CD■, a session reversal command is returned. , the originating terminal determines that CD■ is correct.

Then, in FIG. 10(C), the originating terminal transmits CD■ to the center device, and when the session is reversed, the center device transmits CD■ notifying that there is an error in CD■, and the session is reversed again. The originating terminal immediately interrupts communication.

Next, in Fig. 11, instead of sending the ND after being notified of the CD determination as shown in Fig. 9, the ND is sent to the originating terminal only when the CD decoding is completed and only if there is an error in the CD. CD
12 is a flowchart showing an operation of notifying an error and interrupting communication.

First, when there is an access, the CD is stored and decoding begins. After that, if NDs are sent continuously, check the CD decoding status at the break of each page, and if it is completed, determine whether it is correct or incorrect, and if it is correct, receive the ND as it is. Continue. However, if there is an error, an error notification (for example, RDPBN or RDGR, etc.) is sent upon confirmation immediately after each page is received, and a CD with error notification is sent to the originating terminal by subsequent session reversal, and communication disconnection procedures are performed. to go into.

Next, if the ND is completed or there is no ND, the CD decoding status is checked and the process waits until the CD decoding is completed. At the time of completion, the determination result is judged, and if the result is correct, a mail service corresponding to the contents of this CD is executed.

However, in the case of an error, an error notification CD is sent to the originating terminal and a communication interruption procedure is initiated, as described above.

FIG. 12 is a diagram showing the data transfer procedure in FIG. 11, particularly the procedure when a CD error occurs.

In the figure, T1 is the time taken to complete the CD decoding. When this T1 time has elapsed, if the CD is correct, the process continues; if there is an error in the CD, as shown in the figure (an error notification is returned and the session is reversed). After that, a CD error notification CD■ is sent and the communication is terminated.

As explained above, according to this embodiment, the center device notifies the terminal of the correctness determination result of the control information regarding the message before the terminal sends the message body or during the transmission, so that the message being sent is immediately The sender can understand whether the message was accepted or not. Therefore, messages do not become unsentable and remain unsent, and messages can be communicated reliably and efficiently, improving system reliability and user convenience.

Furthermore, since it is possible to immediately respond and resend, delays in mail delivery are dramatically reduced. Furthermore, since it is possible to notify an error in message control before or while the message itself is being sent, it has the effect of minimizing wasteful communication.

[Effects of the Invention] As described above, according to the present invention, the sender can immediately recognize errors in mail control information, and the transmission of unnecessary messages can be suppressed as much as possible.

[Brief explanation of the drawing]

Figure 1 is a system configuration diagram of this embodiment, Figure 2 is an internal configuration diagram of a mail communication terminal, Figure 3 is a diagram showing the contents of a control document, and Figures 4 (a) to (c) are data Figure 5 is a diagram showing the communication format in the network. Figure 6 is a diagram showing the communication procedure (immediate delivery) between the mail communication terminal and the center device. Figure 7 is the diagram showing the communication procedure between the mail communication terminal and the center device. 8(a) to (e) are diagrams showing the management table in this embodiment. FIG. 9 is a flowchart showing the CD error notification operation in this embodiment. , FIGS. 10(a) to (c) are diagrams showing the communication procedure of the operation shown in FIG. 9, FIG. 11 is a flowchart showing the CD error notification operation in a modified example, and FIG. 12 is shown in FIG. 11. It is a figure which shows the communication procedure of operation|movement. In the figure, 1 to 4... Mail communication terminal, 5... Center device, 6
...Network, 7...Central processing unit, 8...
Main storage device, 9... Mass storage device, 10... Program recording device, 11... Peripheral device, 12... Communication control device, 13... Central processing unit, 14... Main Storage device, 15... Mass storage device, 16... Pressure section,
17... Input unit, 18... Communication control unit. Fig. 2 Fig. 5 Fig. 6 Fig. 0 Fig. 10 (b) Appetizer candy pot > Gap I Fig. 10 (C)

Claims (3)

[Claims] (1) In an e-mail system consisting of a plurality of e-mail communication terminals and a center device having an e-mail storage and exchange function, a discriminating means for discriminating whether mail control information received from the e-mail communication terminals is correct or incorrect, and a discriminating result by the discriminating means An electronic mail system comprising: a transmitting means for transmitting a message to the mail communication terminal; and a communication control means for controlling communication according to a determination result transmitted by the transmitting means. (2) The e-mail system according to claim 1, wherein the sending means sends the message at a boundary between messages received for each page. (3) The e-mail system according to claim 1, wherein the communication control means controls the communication so that if the determination result is correct, the communication is continued, and if the determination result is incorrect, the communication is stopped.