JPS6359135A - Communication equipment - Google Patents

Abstract

PURPOSE:To execute the initialization of a logic channel without requiring backup or the like in terms of a hardware by providing a means sending an interruption instructing packet in multiple access to a 1st communication means and providing a means sending a restart packet to a 2nd communication means. CONSTITUTION:The interruption instructing packet is set to the data part 45 of an LAN frame to set required information for inter-LAN control information 44, the number of the communication server 1 is set to an originating number 43, a multiple access number to all terminal equipments is set to a desitnation number 42 and the interruption instructing packet is sent to the LAN 2 in multiple access. When time is over, it is regarded that all the initializing processings of logic channel in the LAN 2 are finished, the code of a restart request is set to a packet type 33 and the restart request packet setting the parameter 34 required for the restart request is sent. Succeedingly, the reception of the restart confirmation packet from a public packet exchange network 7 is awaited and at the point of time receiving the restart acknowledge packet, the processing is finished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application in Business] The present invention relates to a communication device that interconnects a local area network (LAN) and a public packet switching network.

[Prior Art] Conventionally, a communication server device for interconnecting a local area network (LAN) and a public packet switching network is
In order to enable multiple terminals connected within a LAN and multiple packet type terminals connected to a public packet switching network to communicate with each other, multiplexing of logical channels as specified in CCITTX, 25 Recommendation is performed. There is.

In general, logical channel multiplexing enables communication between multiple terminals, but during the logical channel multiplexing process, the power of the communication server equipment is turned off or a hardware failure occurs, causing the logical channel multiplexing to fail. When the control table etc. for communication server is destroyed, it is necessary to initialize the logical channel control table etc. produced by the communication server, and furthermore, it is necessary to initialize the logical channel control table etc. for the other terminal that was already communicating. An instruction packet must be sent.

However, when the logical channel control table is destroyed due to power off, etc., it becomes difficult to understand how many terminals were communicating with up until now.
Also, since there is no information about the number of the communication partner terminal,
After the communication server device initializes the logical channel control table, it may become unable to send a disconnection instruction packet to the communication partner, and normal logical multiplexing processing may not be possible. Therefore, in order to guarantee normal logical channel multiplexing processing, there is a drawback that measures such as hardware power supply backup are required.

[Problems to be Solved by the Invention] The present invention has been made in view of the problems of the prior art described above, and does not require hardware backup etc.
An object of the present invention is to provide a communication device that can initialize a logical channel.

[Means for Solving the Problems] In order to achieve the above object, the communication device of the present invention has the following configuration.

That is, a communication device that includes a first communication means for communicating with a LAN and a second communication means for communicating with a public packet switching network, and performs communication control via the LAN and the public packet switching network. The first communication means includes means for broadcasting a disconnection instruction packet, and the second communication means includes means for transmitting a restart packet.

[Operation] The above configuration operates to transmit a disconnection instruction packet to the LAN and a restart packet to the public line network when restarting or turning on the power.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Description of communication server device (Figs. 1 and 2)] Fig. 1 shows a local area network (LAN) 2 and public packet exchange that connects a plurality of terminals 3 to 6 according to an embodiment of the present invention. 1 is a configuration diagram of a communication system connected to a network 7 by a communication server device 1. FIG.

FIG. 2 is a block diagram showing the main configuration of the communication server equipment 1 of this embodiment.

In the figure, 20 is a control unit that controls the entire communication server device 1 of this embodiment, and includes a CPU 2 such as a microprocessor.
It has 0-1. 21 is the CPU 20- of the control unit 20;
This is a read-only memory (ROM) that stores, for example, an X, 25 protocol control program executed by the LAN 2, a program and data for controlling the LAN 2, and the like.

22 is a random access memory (RAM) used as a work area for the CPU 20-1 of the control unit 20. 23 is a LAN communication control unit that is connected to the local area network 2 and performs communication control; 24 is a public packet exchange! X, 25, which is connected to 2I7 and transfers packets.
This is the packet communication control unit of

[Explanation of data format (Figs. 3 and 4)] Fig. 3 shows the communication server lung sounds 1 and 25 of the present embodiment.
This is a format diagram of an X, 25 packet used in the packet communication control unit 24, and is shown together with data bit positions.

The format of the figure follows the regulations of CCI TT X, 25, where 30 is a general format identifier, 31 is each logical channel group number, 32 is a logical channel number, and 33 is used as an identifier for the type of packet used in X, 25. . 34 is a packet type identifier in which parameters corresponding to the type of packet are set.

FIG. 4 is a format diagram of a LAN frame used in the LAN communication control unit 23 of the communication server device 1 of this embodiment.

In the figure, 41 is a preamble for synchronizing frames, 42 is a frame destination number, and 43 is a frame transmission source number. 44 is intra-LAN control information for controlling the LAN frame, and 45 is a data section. 46 is a frame check sequence (FCS) for detecting frame transmission errors, and 47 is a postamble indicating the end of the frame.

[Explanation of Logical Channel Table (FIG. 5)] FIG. 5 is a diagram showing the format of a table for multiplexing X, 25 logical channels used in this embodiment and the configuration of the RAM 22.

In the figure, 50 is a logical channel table for controlling logical channel #1, and its starting address is TA
Let's call it BL. Thereafter, tables of necessary logical channels are created corresponding to the number of logical channels. Each logical channel table 50 includes a logical channel number 51, status information 52, a terminal number 53 indicating the communication partner within the LAN, and the D of the terminal connected to the public packet switching network.
It consists of a TE number.

[Operation Description (FIG. 6)] Details of this embodiment will be described below with reference to the flowchart of FIG. 6. This program executed by the CPU 20-1 of the control unit 20 is stored in the ROM 21 in advance, and is executed when the communication server device 1 is powered on or during recovery processing from a failure.

First, in step Sl, x, 2 of the RAM 22 shown in FIG.
Initializes the logical channel table of No.5. Step S
In step 2, a disconnection instruction packet is assembled to be sent into LANZ. This is done by setting a disconnection instruction packet in the data section 45 of the LAN frame shown in FIG. A broadcast number for all terminals is set in each number 42, and this disconnection instruction packet is transmitted within LANZ by broadcast.

In step S3, a timer is set to receive a disconnection confirmation packet from the previous communication partner, and even if a disconnection confirmation packet is received in step S4, the logical channel table has already been initialized in step S1, so the packet is not processed. Ignore it and wait for timeout in step S5. When a timeout occurs in step S5, the LAN
It is assumed that all the initialization processing of the logical channels in Z has been completed, and the process proceeds to step S6.

In step S6, a restart request code is set to the packet type 33 for initializing x925 shown in FIG. 3 to the public packet switching network, and parameters necessary for the restart request are set. Send a start request packet. Subsequently, in step S7, the process waits for the reception of a restart confirmation packet from the public packet switching network 7, and ends the IA filling when the restart confirmation packet is received.

As described above, according to this embodiment, the logical channel control table can be restored in the event of a failure or power cut, without requiring special hardware power backup to cope with destruction of the logical channel control table, etc. Even if such destruction occurs, there is an effect that normal initialization processing of the logical channel can be performed by transmitting a disconnection instruction packet as a broadcast packet on the LAN at the time of failure recovery or power-on.

[Effects of the Invention] As described above, the present invention has the advantage that logical channels can be initialized without requiring hardware backup or the like.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a communication system in which a local area network connecting a plurality of terminals and a public packet switching network are connected using a communication server device according to an embodiment of the present invention. FIG. A block diagram showing the main configuration. Fig. 3 is a diagram of the X, 25 packet format used in the X, 25 packet communication control unit of this embodiment. Fig. 4 is a diagram of the X, 25 packet format used in the LAN communication control unit of this embodiment. L
The AN frame format diagram, Figure 5, is the R frame of this embodiment.
FIG. 6 is a flowchart showing the processing executed when the power is turned on or when recovering from a failure in the device of this embodiment. In the figure, 1... communication server device, 2... LAN, 3...
6...Terminal, 7...Public packet switching network, 20...
・Control unit, 20-1・CPtJ, 21・ROM, 22・
RAM, 23... LAN communication control unit, 24... Packet communication control unit, 42... Destination number, 43... Source number, 44... LAN control information, 45... Data section , 50... logical channel.汀↓v−U Figure 3 Figure 4

Claims (1)

[Claims] The LAN comprises a first communication means for communicating with a LAN, and a second communication means for communicating with a public packet switching network.
and a communication device that performs communication control via the public packet switching network, wherein the first communication means has means for broadcasting a disconnection instruction packet, and the second communication means has means for transmitting a restart packet. A communication device characterized by comprising means for transmitting.