JP2669442B2 - First select facility control system - 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, and more particularly to a first select function, that is, a call request packet from a caller side terminal when communication data is small, and the call request packet. The present invention relates to a fast select facility control method for storing up to 24 bytes of data in a recovery request packet transmitted from a terminal on the other side and transmitting the data.

[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.

[0004] In the virtual call system to which the present invention is directed, an 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.

However, when the data amount of one communication is small such as a credit card inquiry, a call request (CR) packet or a recovery request (C) is issued.
Q) By storing up to 124 bytes or 128 bytes of data in a packet and transmitting it, transmission / reception of a data packet can be omitted. Such a function is called a first select.

FIG. 7 shows a conventional example of the operation of a communication system using such a first select function. In the figure, it is assumed that, for example, a credit card inquiry is made between the POS (Point of Sales, Point of Sale System) terminal 1 and the host computer 2. P
The OS terminal 1 is X. 28, for example, assuming that the POS terminal 1 and the packet network 3 are connected to a circuit switching network.
Between the POS terminal 1 and the X. 28 command to X.
A packet assembling / disassembling function (PAD) 4 for assembling into packets according to H.25 is provided.

In FIG. 7, a call request command from the POS terminal 1 is assembled into a call request (CR) packet in the PAD 4 and sent 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 inquiry 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 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. 8 shows a CR packet format. 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 of the area, it is possible to store call user data such as the above-mentioned credit card inquiry data and a maximum of 124 bytes (octets).

[0009]

However, in FIG. 7, in the call request command from the POS terminal 1,
Depending on the length of the call user data to be stored in the call request packet, for example, if the call user data length exceeds 12 bytes, a request code requesting the first select function must be added to the command. was there.

FIG. 9 shows a conventional example of an input command from a terminal. In the figure (a), the call user data length is 12
(B) indicates a case exceeding 12 bytes. If the call user data length exceeds 12 bytes, "F-" as the first select facility request code is added to the beginning of the command.

FIG. 10 is a processing flowchart of a conventional example of the first select facility control method. In the same figure, in step (S) 5, when a selection PAD command for selecting a communication partner as a call origination request command is received, a call request (CR) packet is edited in S6, and a first select facility request code is added to the command in S7. It is determined whether or not there is, and if there is, S
After the first select facility is added to the CR packet in 8 and the request code is not present, the CR packet is sent to the packet network in S9 without passing through S8. The first select facility is provided in the facility storage area shown in FIG.

As described above, the X. When performing communication using the fast select function by the 28 command, the user must always be aware of whether or not to add the fast select facility request code to the command depending on the length of the call user data. There was a problem that it was not easy to use.

The present invention relates to X. The 28 command is sent to the packet assembling / disassembling function (PAD) without adding the first select facility request code regardless of the call user data length, and the PAD determines the call user data length and When the length exceeds a predetermined length, the purpose is to add the first select facility to the CR packet and send it to the network.

[0014]

FIG. 1 is a functional block diagram of the present invention. FIG. 28 commands and data, and X.28 on the network side. It is a functional block diagram of the first select facility control system in the packet communication system provided with the packet assembling / disassembling function (PAD) which performs bidirectional conversion with 25 packets.

FIG. 1 is a functional block diagram of software stored in, for example, the PAD. In response to a call request command from the terminal at 11, a call user data length in the command, that is, a call packet is stored and received. It is judged whether or not the data length to be transmitted to the side exceeds a predetermined length, for example, 12 bytes, and if it exceeds that length, 12 is used to store up to 124 bytes of data in the outgoing packet. A first select facility as a transmitting function is provided, and a transmission packet is transmitted to the network at 14. On the other hand, if the call user data length does not exceed the predetermined length, the sending packet is sent to the network at 14 without giving the first select facility at 13.

In FIG. 1, the outgoing packet sent from the PAD to the network is, for example, a call request (CR) packet from the calling terminal, or an incoming call (CN) packet in which the CR packet is corrected by the exchange. The received request is a recovery request (CQ) packet from the called terminal. For example, in the case of a credit card inquiry as described with reference to FIG. 7, necessary communication is performed without transmitting / receiving a data packet between the terminals. Will be

[0017]

FIG. 2 is a block diagram showing the overall configuration of a packet communication system using the fast select facility control system of the present invention. In the figure, various terminals are accommodated in a packet network 20, but packet mode terminals (P
T) 21, i.e. X. A terminal implementing the H.25 protocol is directly accommodated in the packet network 20, whereas a terminal implementing X.25.
Non-packet mode terminal (NP
T) or the general terminal 22 is accommodated in the packet network via the packet assembling / disassembling device (PAD) 23.

FIG. 3 is a conceptual diagram of the first select facility control method of the present invention in the communication system of FIG. In the figure, PAD from the terminal (NPT) 22
A call request command including, for example, 13 or more bytes of call user data is input to 23, and the PAD 23 stores the call user data to the packet network 20 and a CR packet to which a first select facility is added. Is sent.

FIG. 4 is a block diagram showing an embodiment of the packet assembling / disassembling apparatus (PAD) shown in FIG. PA
The basic functions of D. D include firstly assembling / disassembling a packet, transferring a packet, and X.D. 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. Such basic functions of PAD and PAD parameters are described in Recommendation X.264. 3 is specified.

In FIG. 4, X. 28 processing unit 25 receives X. 28 commands,
And the transmission data as X. Packetized according to the X.28 procedure. 25 to the processing unit 26. In addition, X. 25, the received packet output from the processing unit 26 is processed by X.25. It is decomposed according to the 28 procedures and output to the terminal 22. X. 25 processing unit 26
Is X. The packet passed from the processing unit 25 is X.28. 25
The packet is transmitted to the packet network 20 according to the procedure, and the packet network 20 transmits the X. The packet received according to the X.25 procedure is X.25.
28 to the processing unit. 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 shows an embodiment of a call request command from a terminal according to the present invention. Comparing this figure with the conventional example of FIG. 9, the first select facility request code is not added regardless of the length of the call user data.

FIG. 6 is a flow chart of a first embodiment of the first select facility control method according to the present invention. In the figure, the selected PA is selected in step (S) 30.
When a D command, for example, a call request command is received, S
The call request (CR) packet is edited at 31, and it is determined at S32 whether the call user data length exceeds 12 bytes. If it exceeds, after the first select facility is added to the CR packet at S33, If it does not exceed 12 bytes, the process of S33 is not performed and S
At 34, the CR packet is transmitted to the packet network.

[0023]

As described above, according to the present invention, it is possible to transmit call user data exceeding 12 bytes without paying attention to the call user data length. The efficiency of communication by 28 commands is improved.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of the present invention.

FIG. 2 is a block diagram showing the overall configuration of a packet communication system using the first select facility control method of the present invention.

FIG. 3 is a diagram illustrating the concept of a first select facility control method according to the present invention.

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

FIG. 5 is a diagram showing an example of a call request command.

FIG. 6 is a processing flowchart of an embodiment of a first select facility control method according to the present invention.

FIG. 7 is a diagram showing a conventional example of operation of a packet communication system using a first select facility.

FIG. 8 is a diagram showing a format of a call request (CR) packet.

FIG. 9 is a diagram showing a conventional example of a call request command.

FIG. 10 is a processing flowchart of a conventional example of a first select facility control method.

[Explanation of symbols]

 20 packet network 21 packet mode terminal (PT) 22 non-packet mode terminal (NPT) 23 packet assembler / disassembler (PAD) 25 X. 28 processing unit 26 X. 25 processing unit 27 X. 29 processing unit 28 PAD parameter

Claims (2)

(57) [Claims] 1. An outgoing call request command and data on a terminal side, and an X.25 command on a network side. In a packet communication system equipped with a packet assembling / disassembling function (PAD) for bidirectional conversion of 25 packets, in the PAD, the call user data length in the call request command from the terminal is It is determined whether or not the length exceeds a predetermined length (11), and when the length exceeds the predetermined length, the first packet as a function of storing up to 124 bytes of data in the transmission packet and transmitting it. A select facility is added (12), and when the predetermined length is not exceeded, the first select facility is not added (1
3) The first select facility control method, wherein the transmission packet is transmitted to a network (14). 2. The fast select facility control system according to claim 1, wherein the predetermined value of the call user data length is 12 bytes.