JPS63208337A - Packet protocol converter - Google Patents

Abstract

PURPOSE:To attain the cost-down by allowing a connection means to connect any of each terminal subscriber interface section and any packet network connection interface section via an input/output path so as to facilitate the changeover of a duplicated system. CONSTITUTION:Only a packet network connection interface section 7a is used normally to constitute logic buses 50-52 and the interface section 7a is connected to terminal subscriber interface sections 6a-6c. If the interface section 7a is faulty, the data transmission on a common input/output bus 8 is in error or a timeout error due to disabled transfer is caused, the interface sections 6a-6c having a connection function detect and judge the error state to constitute logic buses 53-55 in stead of the logic buses 50-52 thereby switching the connection so that a packet network connection interface 7b can be used. Thus, the interface section 7b makes data communication with the interface sections 6a-6c in place of the faulty interface section 7a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a packet protocol (Packet Protocol) used for joining a terminal to a packet switching network.
et Protocol) conversion device.

[Conventional technology]

FIG. 4 is a block diagram showing a state in which a conventional packet protocol conversion device and an embodiment of the present invention are connected to a packet switching network (hereinafter referred to as a packet network). In the figure, 1 is a packet network, 2 is a packet terminal (hereinafter abbreviated as PT), 3 is a non-packet terminal that does not have a packet protocol (hereinafter abbreviated as NPT), and 4 is a packet protocol converter (hereinafter abbreviated as PAD). (abbreviated).

PAD4 is a communication protocol DSL/
It accommodates a plurality of NPTs 3 having a packet protocol, converts the communication protocol of these NPTs 3 into a packet protocol, and connects the NPTs 3 to the packet network 1.

For example, the packet protocol that is the communication protocol in the packet network 1 is the X.25 protocol recommended by the CCITT. PT2 has this X.25 protocol itself, and NPT3 is a terminal that does not have the X.25 protocol itself. It is a machine. In order for NPT3 to join packet network 1, it must join via PAD4. PAD4 performs mutual conversion between various communication protocols used by NPT3 and packet protocols.

Although one PAD 4 may be added to one NPT 3, from the viewpoint of economical efficiency of the entire system, a plurality of NPTs 3 are generally accommodated in one PAD 4.

FIG. 5 is a block diagram showing each functional module in the conventional configuration of the PAD shown in FIG. 4. In Figure 5, the fourth
Components corresponding to those shown in the figures are given the same reference numerals, and their explanations will be omitted.

In the fifth article, 5 is a central processing unit (hereinafter abbreviated as CPU) that performs packet protocol conversion, performs packet protocol processing, logical channel management, input/output bus control, etc. Reference numeral 6 denotes an end non-subscriber interface section, which constitutes an interface for protocols such as non-procedure, basic procedure, and high-level procedure according to the protocol used by each NPT 3. 7 is a packet network connection interface section, which connects to the packet network 1 according to the X.25 protocol. Reference numeral 8 denotes a common input/output bus to which the CPU 5, end subscriber interface section 6, and packet network connection interface section 7 are connected in parallel.

Figure 6 shows each functional module in Figure 5 as 03I (open
system 1nter-connection)
FIG. 2 is a block diagram showing a hierarchical reference model of FIG. In FIG. 6, 10 is the level 1 physical layer (phy
si-cal 1 ayer), 11 is a level 2 data link layer (data 1 ink control 1 a
yer), 12 is the level 3 network layer (netw
13 is a terminal control function, and 14 is a terminal interface for non-packet communication procedures. The terminal control function 13 assembles the non-packet communication procedures of the terminal interface 14 into packets or, conversely, disassembles the packets and converts them into non-packet communication.

The functions of the terminal interface 14 in FIG.
The end of the figure is handled by the non-subscriber interface unit 6,
The end non-subscriber interface unit 6 receives communication data from the NPT 3 and also sends communication data to the NPT 3.

The Pakeso HM connection interface section 7 in FIG. 5 is in charge of the functions of the physical layer 10 and data link layer 11 in FIG. 6. The CPU 5 in FIG. It controls the interface section 6 and the packet network connection interface section 7.

[Problem that the invention seeks to solve]

Conventional packet protocol conversion devices (PADs) are configured as described above, so in order to avoid failures of the packet protocol conversion devices, it is necessary to reduce However, if the processing systems such as the CPU and the packet network connection interface section are made into dual systems in the configuration of a conventional packet protocol conversion device as shown in Fig. 5,
There is a problem in that the operation control method for the dual system, which includes a switching operation that disconnects the failed system and transfers processing to the standby system, becomes complicated, leading to increased costs.

This invention was made in order to solve the above-mentioned problems, and it is possible to easily switch systems in a redundant processing system with a simple configuration, and to reduce costs. The purpose is to provide a protocol conversion device.

[Means for solving problems]

The packet protocol conversion device according to the present invention has terminal interface units 6a, 6b, and 6c connected to each non-packet terminal 3 and having each non-packet protocol function, and a packet protocol conversion device. Each packet network connection interface section 7a, 7b having a terminal control function and a packet protocol function (network layer function section 20) is provided. It has connection means for selectively connecting the packet network connection interface sections 7a and 7b via a common input/output bus 8.

[Effect]

Connection means (subscriber interface sections 6a, 6b.

6C) is the non-subscriber interface section 5a at each end.
, 5b, 5c and each packet network connection interface section 7a, 7b are connected via a common input/output bus 8.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing each functional module of an embodiment of the present invention. 6a in FIG.

6b and 6c are end non-subscriber interface sections corresponding to the end non-subscriber interface section 6 in FIG. End non-subscriber interface sections 6a, 6b.

6C are respectively connected to the non-packet terminals 3 (see FIG. 4) and have non-protocol functions. 7a,
7b corresponds to the packet network connection interface section 7 in FIG. 5, and is also a packet network connection interface section, although the contents are different.

20 is a packet network connection interface section 7a.

7b is a functional module in charge of the CPU 5 in FIG. 5, that is, a network layer functional unit, and has the function of the network layer 12 (packet protocol function) in FIG. 6 and the terminal control function 13.

The end non-subscriber interface sections 6a', 6b, 6c and the packet network connection interface sections 7a, 7b are mutually connected in parallel to a common input/output bus 8, and the end non-subscriber interface sections 5a, 5b, 5c and the packet Data can be transferred in any combination between the network connection interface sections 7a and 7b. However, a transfer method is required to avoid signal collisions on the common input/output bus, and for this purpose, a publicly known bus arbiter method or polling method may be used. The circuit for this is not shown.

Note that the connection state of the packet protocol conversion device 4 is
Since it has been explained in the figure, the explanation will be omitted.

FIG. 2 is a block diagram for explaining the data transfer operation of this embodiment. In FIG. 2, the same reference numerals are given to the components shown in FIG. 1.

50 to 55 indicate logical buses configured on the input/output bus 8. For example, normally only the packet network connection interface section 7a is used to configure the logical bus 50.51.52, and the packet network connection interface section 7a is the terminal non-subscriber interface section 6a.

It is connected to 6b and 6c. Here, if the packet network connection interface section 7a fails, the data transfer on the common input/output bus 8 will be in a timeout error state due to an error or transfer failure, and the end non-subscriber interface sections 6a, 6b, 6c will be in this error state. is detected and determined, and the logical buses 53, 5 are connected instead of the logical buses 50, 51, and 52.
4.55 as r5- and switches the connection so that the packet network connection interface section 7b can be used (function of connection means). Therefore, the packet network connection interface section 7b performs data communication with the end non-subscriber interface sections 6a, 6b, and 6c in place of the failed packet network connection interface section 7a.

FIG. 3 is a flowchart showing the logical bus switching operation explained in FIG. 2. The switching operation will be explained with reference to this flowchart. The end non-subscriber interface section 6a is
In step S1), the communication data from the non-bucketed communication procedure from the NPT 3 (see FIG. 4) is buffered and prepared to be transferred to the packet network connection interface section 7a, and is transferred to the logical bus 50 of the common input/output bus 8. In order to obtain the right to use the bus, it outputs a bus request signal to the input/output bus 8 and waits for a response. If the response is "NO", the determination process in step S2 is repeated, and if the response is rYEsJ, the process advances to step S3 and data is transferred to the packet network connection interface section 7a. When this data transfer is completed, there is a status report from the packet network connection interface section 7a, which causes the terminal non-subscriber interface section 6 to
Step a determines whether this status report is a normal termination report (step S4), and if rYEsJ, the process proceeds to step S5. In step S5, the data transferred to the packet network connection interface section 7a is packetized, left to the operation of the network layer function section 2o, and communicated to the packet network 1.

On the other hand, if "NO" in step S4, that is, it is a report of abnormal termination, or if there is no status report within a predetermined time after the end of step S3, step S6
Enter the input/output bus 8 helicopter to change the destination. That is, the end non-subscriber interface section 6a outputs a bus request signal for obtaining the right to use the logical bus 53 to the input/output bus 8, and changes the destination address to the destination packet network connection interface section 7b. In this way, the other party of communication is connected to the packet network connection interface unit 7.
After changing to b, the process returns to step S2 and similar processing is performed, and when step S5 is entered, the data transferred to the packet network connection interface section 7b is packetized and communicated to the packet network 1. That is, the non-packet terminal 3 and the packet network 1 are connected and data communication is performed. Such a switching operation facilitates system switching in a duplex processing system.

In the above embodiment, the end non-subscriber interface section 6a
Although the switching operation between the end non-subscriber interface section 6b, 6c and the packet network connection interface section 7a or 7b has been described, the switching operation between the end non-subscriber interface section 6b, 6c and the packet network connection interface section 7a or 7b can also be performed by the same process. It will be done.

〔Effect of the invention〕

As described above, according to the present invention, the non-subscriber interface section at each end is connected to each non-packet terminal in a corresponding manner and has each non-packet protocol function, and the terminal control function and the packet protocol among the packet protocols. Each terminal is provided with a packet network connection interface section having a function, and each terminal is connected to the subscriber interface section and each packet network connection interface section via a common input/output bus.
By having a connection means that can be connected four times, the configuration can be simplified, systems can be easily switched in a duplex processing system, and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing each functional module of an end non-subscriber interface section and a packet network connection interface section according to an embodiment of the present invention, and FIG. 2 is a block diagram for explaining the data transfer operation in this embodiment. 3 is a flowchart for explaining the switching operation of the logical bus in FIG. 2, FIG. 4 is a block diagram showing the connection state of the packet protocol converter of the conventional and this embodiment, and FIG. FIG. 6 is a block diagram showing functional modules in the configuration of a conventional packet protocol conversion device. FIG. 6 is a block diagram showing the functional modules of FIG. 5 in a hierarchical manner in the O3I reference model. 1...Packet switching network, 3...
...Non-13=Packet terminal, 4...Packet protocol converter, 6a, 6b, 6c...End non-subscriber interface unit, ? a, 7b... Packet network connection interface section, 8... Input/output bus, 20.
...Network layer functional unit (including terminal control function and packet protocol function).

Claims (1)

[Claims] A plurality of non-packet terminals that do not have a packet protocol, which is a communication protocol in a packet switching network, are accommodated, and the communication protocol of these non-packet terminals is converted to a packet protocol, and the non-packet terminals are connected to the packet conversion network. In the packet protocol conversion device connected to the above-mentioned non-packet terminals, each terminal subscriber interface section is connected correspondingly to each of the above-mentioned non-packet terminals and has each non-packet protocol function, and the terminal control function and the packet protocol among the above-mentioned packet protocols. each packet network connection interface section having a function, and a connection means for selectively connecting the non-subscriber interface section at each end and each packet network connection interface section via a common input/output bus. A packet protocol conversion device characterized by: