JP2669441B2 - DTE facility control method using AT command - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet communication system. The present invention relates to a DTE facility control method using AT commands, which makes services from various networks available from terminals supported by 28 commands, that is, DTE facilities available also in modems and the like supported by AT commands.

[0002]

2. Description of the Related Art In a packet switching system, data information is not directly transmitted and received between terminals as in a data communication system using a conventional circuit switching network.
Data transmission is performed using store-and-forward. That is, the data information sent from the originating terminal is temporarily stored in the memory in the exchange, then transmitted at high speed in the network, and finally delivered to the partner terminal. Data information flowing in the network is divided into fixed lengths, each of which is divided into packets each having a header including destination information and the like,
The exchange performs the exchange processing in packet units.

In a packet switching network, a virtual call system in which a logical link is set between terminals during communication, a permanent virtual call system in which a fixed logical link is set between terminals, and a logical call system between terminals. There is a datagram method that does not set up a link, that is, does not take the concept of a call.

For example, in the virtual call system, the international recommendation, X. The setting of the logical link is performed in accordance with 25.
When this logical link is set, that is, when a call is connected, a calling request (CR) packet is sent from the calling terminal to the network, and the packet is converted into a called (CN) packet by an exchange in the network, and the called terminal is changed to a called (CN) packet. And the called terminal sends an incoming call acceptance (CA) packet, which is converted to a connection completion (CC) packet by the exchange and sent to the calling terminal, and the call connection is terminated. Done. Then, at the time of call release, a call release procedure is started by sending a recovery request (CQ) packet to the network from either the calling side or the called side terminal.

[0005] However, when the data amount of one communication is small as in the case of introduction of a credit card, for example, a call request (CR) packet or a recovery request (C
Q) By storing up to 128 bytes of data in a packet and transmitting it, transmission and reception of a data packet can be omitted. Such a function is called a first select.

FIG. 11 shows an operation example of a communication system using such a fast select function. In the figure, it is assumed that, for example, a credit card is introduced between a POS (point of sale, point of sale system) terminal 1 and a host computer 2. POS
Terminal 1 is X. For example, assuming that the POS terminal 1 is connected to a circuit switching network, the X.0. 28 command to X. 25
A packet assembling / disassembling function (PAD) 4 for assembling packets according to

In FIG. 11, a call request command from the POS terminal 1 is assembled into a call request (CR) packet in the PAD 4 and transmitted to the packet network 3. This packet is received by a switch inside the packet network 3 (C
N) The packet is converted into a packet and delivered to the host computer 2. From the host computer 2, credit card introduction reply data is stored in a recovery request (CQ) packet and sent to the packet network 3. The exchange converts it into a disconnection instruction (CI) packet and delivers it to the PAD 4, where it is stored. Is sent to the POS terminal 1. It is to be noted that the X.0 sent from POS1 to PAD4 first. The 28 commands will be described later.

FIG. 12 shows a format of a CR packet. In the figure, a CR packet includes a logical channel group number (LCG) indicating a logical channel to be used.
N), a logical channel number (LCN), a subscriber number (DA) of the called terminal, and a subscriber number (SA) of the calling terminal are stored. At the end thereof, it is possible to store a maximum of 128 bytes (octets) of call user data such as the above-mentioned data for credit card introduction. In addition, an area for storing a facility as a service function required by the network from a data terminal equipment (DTE) such as a terminal is provided on the call user data, such as first select.

FIG. 13 shows the X.X. 28 is an example of a call request command according to No. 28. In the figure, "F-" as a first select facility request code is added to the head of the command.

As described above, X. In the DTE (devices with data input and / or output functions such as data terminal equipment, terminals, etc.) supported by 28 commands, various DTE facilities other than the first select facility are used. can do. Other DTE facilities include an incoming billing request facility for requesting incoming billing, an RPOA selection facility for selecting an RPOA value for specifying a relay network for a packet, and the length of one packet, ie, a packet size for specifying a packet size. In the data transfer state after the call is set up between the negotiation facility and the DTE, the other party's D
There is a facility size negotiation facility that specifies the size of the window as the number of data packets that can be continuously received from the TE.

[0011]

SUMMARY OF THE INVENTION However, X.A. 2
In a DTE that does not support 8 commands, for example, an analog modem that is supported by the AT command targeted in the present invention, there is a problem that such a DTE facility cannot be used. The AT command is such that the data format and data rate are automatically detected by entering AT at the beginning of the command.

FIG. 14 is a flowchart of a conventional example of a call request packet sending process based on an AT command. In the figure, when an AT command (dial command) is received in step (S) 6, a call request (CR) is made in S7.
The packet is edited, and the call request packet is sent to the network in S8. In this case, DT is added to the call request packet.
Since the E facility cannot be provided, the packet size and the window size are fixed to default values, for example, and the communication throughput cannot be increased.

According to the present invention, even if an AT. 28
The purpose of this is to make it possible to use the DTE facility in the same way as when using a command.

[0014]

FIG. 1 is a block diagram showing the principle of the first invention. This figure shows AT commands and data on the terminal side and X. It is a principle block diagram of a DTE facility control system using an AT command in a packet communication system having a packet assembling / disassembling function (PAD) for performing bidirectional conversion into 25 packets.

In FIG. 1, a DTE facility menu registration means 10 is used to register, for example, from the terminal side, a menu relating to a facility as a service function required by a network from a data terminal equipment (DTE) including a terminal. The facility includes, for example, an incoming billing request.

The AT command identification means 11 identifies the transmission of an AT command input from the terminal side, the transmission packet editing means 12 edits the transmission packet, and the DTE facility editing means 13 registers the DTE facility menu in the transmission packet. The DTE facility registered in the means 10 is provided.

In FIG. 1, the command from the terminal is AT
When the command is identified by the command identifying means 11 as an AT command, an outgoing packet to which a facility already registered in the DTE facility menu registration means 10 is added is transmitted to the network in accordance with the command.

[0018]

In the first invention shown in FIG. 1, for example, the DTE facility to be added to the outgoing packet is registered in the DTE facility menu registration means 10 from the terminal or the front panel of the PAD device, and the AT command is actually sent to the terminal. When input from the side, the registered facility is added and the outgoing packet is sent to the network.

FIG. 2 is a functional block diagram of the second invention. The principle block diagram for the second invention is the same as FIG. 1 showing the principle of the first invention. However, in the first invention, the DTE facility menu registration means 10
In the second invention, the registered content is always added to the outgoing packet, whereas the registered content is a default value, that is, a value automatically determined on the network side when there is no request as a facility. When
The difference is that the DTE facility is not added to the outgoing packet. Therefore, the second invention is applied to facilities having default values, for example, packet size negotiation and window size negotiation.

In FIG. 2, when a command from the DTE is identified as an AT command at 16, it is determined at 17 whether a designated value in the already registered DTE facility, for example, a packet size value is a default value or not. When it is determined and the default value is not set, the outgoing packet to which the DTE facility having the designated value is added is sent to the network at 18, and when the default value is set, the outgoing packet is sent to the network without adding the facility registered at 19. Sent out.

In the second invention, when the contents registered in the DTE facility menu registration means 10 indicate the default value, the reason why the facility is not given is that the contractor of the line has not contracted for the facility. This is to prevent the transmission of a packet to which the facility is assigned when there is no contract.

As described above, according to the present invention, the DTE facility can be used by registering the facility menu in advance.

[0023]

FIG. 3 is a diagram for explaining the concept of the DTE facility control system according to the present invention. In the figure, a packet assembling / disassembling (PAD) device 23 is provided between a terminal 21 supported by an AT command and a packet network 22. When the selection result of the packet size of 256 bytes is registered in the PAD 23 as a menu for the packet size negotiation facility as the DTE facility, for example, since this 256 bytes is not the default value, for example, 128 bytes, In both the first and second inventions, when an AT command starting with "AT" is input from the terminal 21, X. In accordance with 25, for example, a call request (CR) packet is provided with a packet size negotiation facility and output to the packet network 22.

FIG. 4 is a block diagram of an embodiment of a packet assembling / disassembling (PAD) device. The basic functions of the PAD are as follows: first, packet assembly / disassembly, packet transfer, Management of 25 virtual calls, and secondly, control of a start-up terminal, that is, transfer of start-up data, processing of control characters, and the like. The execution method of these basic functions, for example, packet assembly and transmission conditions to the packet network (reception and transmission timing of specific control characters, etc.) are parameterized as PAD parameters, and can be specified according to user needs. ing.

In FIG. 4, the menu processing unit 24 selects the presence / absence of these facilities according to the result of menu registration relating to incoming call billing request, RPOA selection, and various facilities such as packet size and window size negotiation. The AT command processing unit 25 is the terminal 2
The AT command and the transmission data input from step 1 are packetized, and 25 to the processing unit 26. X. 2
5 The received packet output from the processing unit 26 is decomposed and output to the terminal 21. X. 25 processing unit 26 sends the packet passed from the AT command processing unit 25 to the X.25. 25 to the packet network 22 according to the X.25 procedure. The received packet is output to the AT command processing unit according to the 25 procedures. In addition, X. A processing unit 27 exchanges control information and user data with a packet mode terminal or another PAD. Further, a PAD parameter 28 is a parameter specified according to the user's needs when assembling / disassembling a packet. Is.

FIG. 5 is a detailed block diagram of the menu processing unit and the AT command processing unit in the PAD of FIG. In the figure, a menu related to a DTE facility is registered in a menu processing unit 24, and the result is processed.
The selection menu registration unit 31, the packet size menu registration unit 32, the window size menu registration unit 33, and data for each registration unit. The AT command processing unit 25 includes an AT command transmission identifying unit 34 for identifying the transmission of the AT command from the terminal 21, a transmission packet editing unit 35 for editing the transmission packet, and an incoming billing request for adding various facilities to the transmission packet. Facility editing unit 36, RPOA selection facility editing unit 3
7, a packet size negotiation facility editing unit 38 and a window size negotiation facility editing unit 39.

FIG. 6 shows a call request (C) in the first invention.
It is an example flowchart of R) packet transmission processing.
In the figure, when an AT command, that is, a dial command is received in step (S) 41, a call request (CR) packet is edited in S42, and a facility menu, for example, a packet size menu is registered in S43. It is determined whether or not there is a registration. After the packet size negotiation facility is added to the call request (CR) packet corresponding to the value of the packet size registered in S44, there is no registration again. In case S4
The CR packet is sent to the network in S45 without performing the process of 4.

FIG. 7 is a flowchart of a call request packet sending process according to the second invention. In the same figure, as in FIG. 6, the AT command is received in S48, and CR in S49.
After the packet has been edited, it is determined in S50 whether the registered value of the packet size menu is a default value. If not, the packet size corresponding to the registered packet size value in S51 is determined. After the negotiation facility is given to the CR packet, if the default value is set, the CR packet is sent to the network in S52 without performing the process of S51.

In FIGS. 6 and 7, the CR packet transmission processing has been described by taking the packet size negotiation facility as an example of the DTE facility, but it goes without saying that the facility is not limited to the packet size negotiation. It is also possible to provide two or more facilities to one CR packet. FIG. 8 shows an example of a CR packet to which two facilities of a packet size negotiation facility and a window size negotiation facility are added.

In the present embodiment, the menu can be registered in the menu processing section 24 of FIG. 5 from the terminal 21 or can be input from the front panel of the PAD 23.

FIG. 9 is an explanatory diagram of the input from the terminal. Here, the input method for the packet size and window size negotiation facility is shown.

FIG. 10 shows an example of menu input from the front panel of the PAD device. As in FIG. 9, a menu input method for the packet size and the window size negotiation facility is shown.

[0033]

As described above, according to the present invention, A
In analog modems and the like supported by the T command, the X.T. It is possible to utilize various DTE facilities as in terminals supported by 28 commands. Then, the packet size, window size, and the like can be set to be equal to or larger than the default values, which greatly contributes to improvement in communication throughput.

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the first invention.

FIG. 2 is a principle block diagram of the second invention.

FIG. 3 is a diagram illustrating the concept of a DTE facility control method using an AT command according to the present invention.

FIG. 4 is a block diagram showing a configuration of an embodiment of a packet assembling / disassembling (PAD) device.

FIG. 5 is a block diagram illustrating a detailed configuration of a menu processing unit and an AT command processing unit in FIG. 4;

FIG. 6 is a flowchart of an embodiment of a call request packet sending process according to the first invention.

FIG. 7 is a flowchart of an embodiment of a call request packet sending process according to the second invention.

FIG. 8 is a diagram showing an example of a call request packet provided with two DTE facilities.

FIG. 9 is a diagram showing a method of inputting menu registration from a terminal.

FIG. 10 is a diagram showing a method of inputting menu registration from the front panel of the PAD device.

FIG. 11 is a diagram showing an operation example of a packet communication system using the first select facility.

FIG. 12 is a diagram showing a format of a call request (CR) packet.

13 is a diagram showing an example of a call request command (X.28).

FIG. 14 is a flowchart of a conventional example of a call request packet transmission process using an AT command.

[Explanation of symbols]

10 DTE facility menu registration means 11 AT command identification means 12 Outgoing packet editing means 13 DTE facility editing means 21 Terminal 22 Packet network 23 Packet assembling / disassembling (PAD) device 24 Menu processing unit 25 AT command processing unit 26 X. 25 processing unit 30 incoming call charge request menu registration unit 31 RPOA selection menu registration unit 32 packet size menu registration unit 33 window size menu registration unit 34 AT command outgoing identification unit 35 outgoing packet editing unit 36 incoming call request facility editing unit 37 RPOA selection facility Editing unit 38 Packet size negotiation facility editing unit 39 Window size negotiation facility editing unit

Claims (3)

(57) [Claims] 1. An AT command and data on a terminal side,
X. on the network side. In a packet communication system equipped with a packet assembling / disassembling function (PAD) that performs bidirectional conversion with 25 packets, in the PAD, as a service function required for a network from a data terminal equipment (DTE) including terminals. DTE facility menu registration means (10) in which a menu relating to facilities is registered; AT command identification means (11) for identifying transmission of an AT command from the terminal (DTE); and transmission packet editing means for editing a transmission packet (1
2) and a DTE facility editing means (13) for adding a DTE facility to the outgoing packet.
And transmitting a transmission packet to the network to which a DTE facility registered in the DTE facility menu registration means (10) has been added to the command when the command from the terminal is identified as an AT command. DTE facility control method using 2. The DTE facility registered in the DTE facility menu registration means (10) is an incoming charging request facility, a facility for designating and selecting a packet relay network, a packet size negotiation facility for designating a packet size value, 2. The DTE facility control method using an AT command according to claim 1, wherein the DTE facility control method is at least one of a window size negotiation facility for designating a window size value. 3. An AT command and data on a terminal (DTE) side, and an X.400 command on a network side. In the packet assembly / disassembly function (PAD) that performs bidirectional conversion with the
A command from the TE is identified as an AT command (1
At 6), it is judged whether the specified value in the already registered DTE facility is the default value (17), and when it is not the default value, the outgoing packet with the DTE facility having the specified value is sent to the network. (18) When the default value is used, the outgoing packet is sent to the network without adding the registered DTE facility (19).
TE facility control method.