JPS61264939A - Exchange device for local area network - Google Patents

Abstract

PURPOSE:To attain the connection of its own line loop from a terminal via an exchange in an LAN by changing a connecting operation depending when an outgoing terminal equipment and an incoming terminal equipment are coincident and dissident. CONSTITUTION:When the level of the line T of the outgoing terminal equipment 3101 goes to logic 1, a signal transmission/reception section 3206 detects the level '1' of the line T via a terminal connecting device 3001, a subscriber line connecting section 3301 and a subscriber line bus 3207 and a calling is informed to a channel control section 3205. When the channel control section 3205 indicates the transmission of a selection signal transmission enable signal to the signal transmission/reception section 3206, the level '1' is sent to the line R of the outgoing terminal equipment 3101 from the signal signal transmission/reception section 3206 to attain the selection signal transmission enable state and the terminal equipment 3101 sends a selection signal. The channel control section 3205 analyzes the selection signal and uses an incoming terminal equipment discriminating function to discriminate whether terminal the outgoing call is equal to the receiving terminal or not, and when a talking enable signal comes from an incoming terminal equipment, the talking enable signal is sent to the outgoing terminal equipment 3101, a channel 3204 is set to apply channel connection. Thus, the terminal of the remote side can confirm the operation of the exchange.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a switching device for a LAN (Local Area Network) that performs switching connections of data terminals and the like.

[Conventional technology]

Figure 5 is a diagram showing the configuration of the line switching network (hereinafter referred to as DDX line switching network) of the Japan Telecommunications Corporation digital data exchange network as a conventional LAN, as shown in, for example, Basic Knowledge of Data Exchange @ (edited by the Telecommunications Association). be.

In the figure, Ia and lb are data terminal devices as a calling terminal and a receiving terminal, 2 is a home line termination device, 3 is a concentrator multiplexing device, 4 is a time-division channel device, and time-division switches 4&, It has a concentrator multiplexer control section 4b and a signal transmitting/receiving section 4C.

FIG. 6 shows the data terminal device 1m in FIG.

1b and an interface between the home line terminal device 2. FIG. Further, FIG. 7 shows a signal sequence at the terminal interface when the data terminal devices 1m and 1b request a switching connection f: to the switching network (the area within the broken line in FIG. 5 is referred to as the switching network).

Next, the operation of switched connections in a switched network will be explained. When the data terminal equipment f11m on the calling side makes a call by setting the T line of the terminal interface to 1#, the R line becomes @1# and enters the selection signal sending state.

Subsequently, the data terminal device 1 as the originating terminal sends out a selection signal to the T line. The switching network 5 receives the selection signal, analyzes it, and selects the selected partner terminal 0Rill-
A call is made by setting it to @1'.

When the data terminal device 1b as a receiving terminal detects @1m on the R line, it changes the T line to @1' and immediately responds by sending a call ready signal Ack if connection is possible.

In response to this response, the switching network 5 sends a partner confirmation signal ID and a call availability signal Ack to the R line of the calling terminal, and
Perform all line connections between the calling terminal and the receiving terminal. Thereafter, data communication can be performed between the calling terminal 1 and the receiving terminal without being in a communication state. When the communication is completed, the T-line of the originating terminal or the terminating terminal can be continued for a certain period of time using an "O" K, and a recovery request can be made to disconnect the switched connection line. After cutting, it will start.

Both T@ and R@ of the inking terminal become 10 m and the state becomes ready.

Next, when the originating terminal and the receiving terminal are the same, that is, when a connection request is issued to the own terminal, the following operation occurs. The process from making a call to sending out a selection signal is the same as the connection operation described above. When the switching network receives the selection signal, it analyzes it and checks whether the other party is in a ready state, and if so, it can call the other party. However, when the originating terminal makes a call to its own terminal, the T line is already at @11 and is not in a ready state, so the other party's terminal becomes busy and the connection is refused.

[Problem that the invention seeks to solve]

Since the conventional DDX line switching network is configured as described above, the calling terminal connects to its own terminal, that is, the terminal performs a self-loop test via the time-division channel device 4 serving as an exchange in the switching network. I can't connect to the line to do so.

Therefore, when constructing a LAN for switching connection of data terminals, etc., there is a problem in that a self-loop test cannot be performed via an intra-LAN exchange simply by creating a network with functions similar to the DDX circuit switching network.

This invention was made in order to solve the above-mentioned problems, and provides a switching device for a local area network that can perform normal switching connections as well as self-circuit loop connections from terminals via an intra-LAN switch. The purpose is to obtain fin.

[Means to resolve the problem]

The switching device for a local area network according to the present invention has a communication path section and a communication path control section signal transmission/reception section, and the communication path control section has a receiving terminal control function for determining whether a calling terminal number and a called terminal number are equal. The connection operation is changed depending on whether the originating terminal and the terminating terminal match and the case where the originating terminal and the terminating terminal do not match.

[Effect]

In the local area network exchange according to the present invention, the incoming terminal discrimination function of the call path control unit determines whether the incoming terminal is a calling terminal;
After seconds have elapsed, a call-ready signal is sent to establish a call path, and when the calling terminal ζ is determined as the receiving terminal, the caller is called only when the other party's terminal is ready, and after receiving the call-ready signal from the other party, the calling terminal is A communication path connection can be established by sending out a communication ready signal.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows a configuration diagram of a LAN and a distributed switching device.
0000 is a ring-shaped transmission path, 1000 is a ring management device, 2000, 3000, 4000 is a distributed switching device, 2001, 3001 to 3099, 400
1 is a terminal connection device, 2101, 3101 to 3198
, 4101 is a terminal device, 3201 is a ring access unit,
3202 is a common line signal transmission/reception unit, 3203 is a multiplexing unit,
3204 is a communication path section, 3205 is a communication path control section, 320
6 is a signal transmission/reception unit, 3207 is a subscriber line bus, 3301
-3399 are subscriber line connections.

FIG. 2 shows an operation sequence diagram (normal exchange connection) when the originating terminal and the terminating terminal are different in the distributed switching device 3000 or the like.

FIG. 3 shows an operation sequence diagram when the originating terminal and the terminating terminal are the same in the distributed exchange fIt3000 or the like.

FIG. 4 is a diagram showing an exchange connection operation flow by distributed exchange devices 3000 and the like.

First, the normal exchange connection operation will be explained. For example, if the terminal device 3101 is the originating terminal and the terminal device 3199 is the receiving terminal, if the T line of the originating terminal 3101 becomes "1#", the terminal connection device 3001, subscriber line connection section 33
01, 11# of the T line is detected in the signal transmitting/receiving section 3206 via the subscriber line bus 3207 t-, and the call path control section 3205 is notified of the call origination. Call path control unit 32
05 instructs the signal transmitting/receiving unit 3206 to send a selection signal sending enable signal, the signal transmitting/receiving unit 3206
@1'' is sent to the R line of the originating terminal 3101, and becomes a selection signal sending enable signal.The originating terminal 3101 thereby sends out the selection signal.

The selection signal is received by the signal transmitting/receiving section 3206 and passed to the communication path control section 3205. The call path control unit 3205 analyzes the selection signal, determines the calling terminal N and the called terminal using the called terminal discrimination function, and then selects T@, R from the other party's terminal 3199.
The signal transmitting/receiving unit 3206 monitors whether the line is in a ready state, and if the other party's terminal is ready, the receiving party's terminal 319
9 is called. When a call-ready signal is responded from the receiving terminal, the call-ready signal is immediately sent to the calling terminal 3101, a call path 3204 is set, and the call path is connected. In this way, the calling terminal 3101 and the receiving terminal 3199
0 circuit switched connections are made.

Next, the operation when the calling terminal and the receiving terminal are the same terminal will be explained.

When the terminal 3101 makes a call to itself, the process up to the sending of the selection signal is the same as in the case of the normal exchange connection described above. When the call path control unit 3205 receives and receives the selection signal through the signal transmitting/receiving unit 3206't, it analyzes it and can determine that the calling terminal number=the receiving terminal number using the receiving terminal determination function. At this time, the call path control unit 3205 unconditionally sends out a call-ready signal to the called terminal without checking whether the called terminal is ready or busy.
and connect the call path. In this way, if a terminal requests a connection f: to its own terminal, the connection becomes possible.

These exchange and connection operations are represented by a 70-chart as shown in FIG.

In the above embodiment, when the calling terminal is the receiving terminal, a call ready signal is sent out and a call path is established t seconds after receiving the selection signal, but the time in seconds can be determined as needed. It can be determined by

Further, although the above embodiment shows a connection operation sequence for an asynchronous terminal, this can also be applied to a synchronous terminal.

〔Effect of the invention〕

As described above, according to the present invention, since the originating terminal can request connection to its own terminal, the terminal can connect from the remote side by making its own line loop connection via the LAN exchange. It is possible to check the operation of the exchange, and it also has the advantage that line error rate tests of subscriber lines via the exchange can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a local area network switching device according to an embodiment of the present invention, and FIG. FIG. 3 is a sequence diagram showing the operation of the device shown in FIG. 1, FIG. 4 is a flow chart diagram showing the operation of the device shown in FIG. 1, and FIG. 5 is a configuration diagram showing a conventional DDK circuit switching network. , FIG. 6 is a block diagram showing the terminal interface in FIG. 5, and FIG. 7 is a diagram showing a sequence showing the operation of the DDX circuit switching network shown in FIG. 5. 1000 is a ring-shaped transmission line, 2000 and 3000. 4000 is the exchange device, 2001, 3001-3091
．． 4001 is a terminal connection device, 2101, 3101-3
109 and 4101 are terminal devices, 3201 is a ring access unit, 3205 is a communication path control unit, 3206 is a signal transmission/reception unit, 3207 is a subscriber line bus, 3301 and 3399
is the subscriber line connection section. Patent applicant: Mitsubishi Electric Corporation 1□--□ Agent: Patent attorney 1) Hiroshi Sawa (2 others) - Figure 1 Figure 3 11I4rIA Figure 7? Lid procedure amendment (voluntary) September 1, 1985

Claims (1)

[Claims] In a local area network switching device that is interposed in a ring-shaped transmission path and exchanges data between each terminal, a call path control unit provided in the local area network switching device is provided with a call terminal identification function. If it is determined that the calling terminal and the receiving terminal match by holding the terminal, a call ready signal is sent after t seconds have elapsed regardless of whether the terminal is ready or the terminal is busy, and the communication path is connected. A switching device for a local area network, characterized in that when a mismatch is detected, a call is made to the other party only when the other party's terminal is ready, and a communication path is established after receiving a call ready signal from the other party.