JPH1117736A - Automatic line identification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To connect various terminals through a device that corresponds to different lines and to maintain the transmission characteristics of a transmission line by successively identifying transmission codes through plural identification circuits corresponding to the instruction of a timer control circuit and fixing the timer control circuit and a digitized part switching part while even one piece of the information of the identified result is fixed. SOLUTION: Identification circuits 12a, 12b, 12c and 12d recognize the kinds of transmission codes and confirm the synchronism of respective electric signals, and when the synchronism is established, a synchronism establish signal 120 is immediately transmitted to a timer control circuit 11 and a digitizing part 2. In the timer control circuit 11, a transmission line 100 and the identification circuits 12a-12d are physically switched, and when the synchronism is not established for the identification circuits 12a-12d at all, the identification circuits 12a-12d are switched for the unit of fixed time. Based on synchronizing information from the identification circuits, a digitizing part switching part 3 switches the digitizing part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching apparatus for accommodating a plurality of terminals having various transmission systems and transmission rates, digitizing the various terminal data, and performing switching transmission processing.

[0002]

2. Description of the Related Art Conventionally, as an example of this type of switching device, a multiplexing device (hereinafter abbreviated as a conventional multiplexing device) disclosed in Japanese Patent Laid-Open No. 4-263542 and an IEEE of ANSI have been proposed.
802.3u Article 28 (hereinafter abbreviated as conventional standard device)
Is raised.

FIG. 3 is a diagram showing an example of a conventional multiplexer. This device relates to a multiplexer for multiplexing signals from a plurality of terminals including a voice terminal, and the coding rate of the voice terminal is variable. Functions provided for that purpose include an encoding unit, a statistical multiplexing unit, a usage detection unit, and an encoding rate switching unit. Describing each means, the encoding means performs an audio signal from an audio terminal, the statistical multiplexing means converts cells from a plurality of terminals including the output of the encoding means into cells, and the usage detecting means The usage rate of the terminal is detected, and the coding rate switching means switches the coding rate of the coding means according to the usage rate detected by the usage detection means. In particular, the functions of the usage detecting means and the coding rate switching means automatically switch the code rate according to the usage of the terminal. It has a function of increasing the coding rate when there is room in the processing on the multiplexing device side and lowering the coding rate when there is no room. As a result, when the number of connected terminals is large, minimum quality is guaranteed and many terminals are accommodated, and when the number of connected terminals is small, high quality transmission can be performed.

FIG. 4 is a diagram showing a configuration of a fast link pulse of a conventional standard device. The conventional standardization device has a negotiation function in which, when terminals are connected to each other, or when a terminal and a communication device are connected, the respective transmission methods are transmitted in advance. This system is based on the 10 base-t system. Then, information called a fast link pulse defined therein is exchanged with each other to determine a usable transmission rate. In FIG. 4, the packet format of the terminal identification flowing on the transmission path includes a selector field (5 bits) A, a technology ability field (8 bits) B, and a field (3 bits) C.

[0005]

The above-described prior art has the following problems.

First, in the multiplexing device described in Japanese Patent Laid-Open No. 4-263542, the coding rate can be identified. However, if the transmission system of the terminal detected by the usage detecting means is not fixed, No. For this reason, there is a problem that terminals having different transmission systems cannot be connected.

In a conventional standard device, a terminal and a switching device recognize a transmission mode using a negotiation function conforming to IEEE802.3.
There is a problem in that terminals without the negotiation function cannot connect to each other.

Accordingly, an object of the present invention is to solve the above-mentioned problems by enabling various terminals to be connected by two line-compatible devices and automatically identifying a line without deteriorating the transmission characteristics of the transmission line. It is to provide a device.

[0009]

In order to achieve the above object, an automatic line identification apparatus according to the present invention comprises a line corresponding unit accommodating a plurality of terminals and a switching unit. In a line identification device in which a line handles a plurality of transmission codes, a line corresponding unit includes a transmission code identification unit for identifying transmission codes of various terminals, a plurality of digitizing units for digitizing the transmission codes, and a transmission code identification unit. A digitizing unit switching unit for selecting a corresponding digitizing unit from the plurality of digitizing units based on the identification result information; and a packetizing unit for packetizing digital data of the digitizing unit switching unit and sending the packetized data to the switching unit. A transmission code identification unit, a plurality of identification circuits having different transmission codes of the terminal, an identification switching circuit for performing physical switching between the plurality of identification circuits and the transmission line, and fixing after the switching. A fixed circuit and a timer control circuit having a clock circuit are provided. A plurality of identification circuits sequentially identify transmission codes according to an instruction from the timer control circuit, and as long as at least one identification result information is determined, A timer control circuit and a digitizing unit switching unit are fixed.

It is preferable that the packetizing section has a function of switching a packet size between a fixed length packet and a variable length packet.

Further, it is preferable that the transmission code identification unit has a function of recognizing synchronization of the transmission code.

Further, it is preferable that the plurality of identification circuits perform clock synchronization in order to recognize the type of the transmission code.

It is preferable that the clock circuit presets minimum time information required for establishing clock synchronization in each of the plurality of identification circuits in advance.

Further, when the plurality of identification circuits have established clock synchronization, it is preferable to immediately transmit a synchronization establishment signal to the timer control circuit and the digitizing unit switching unit.

Further, it is preferable that the synchronization establishment signal is an electrically high level signal, and the synchronization non-establishment signal whose synchronization is not established is an electrically low level signal.

When the fixed circuit establishes clock synchronization for any one of the plurality of identification circuits, it is preferable that the connection between the corresponding identification circuit among the plurality of identification circuits and the transmission path is fixed.

Further, it is preferable that the identification switching circuit physically connects and disconnects the plurality of identification circuits and the transmission line based on switching information from the fixed circuit.

Further, it is preferable that a plurality of digitizing units convert the code signal of the transmission path into a binary digital signal.

The automatic line identification apparatus of the present invention is an exchange apparatus having a line correspondence unit accommodating a plurality of various terminals and an exchange unit, wherein one line connected to the line correspondence unit can handle a plurality of transmission codes. A transmission code identification unit for identifying a transmission code of a terminal, a digitizing unit for digitizing the transmission code, and a digitizing unit switching unit for selecting a digitizing unit based on identification result information of the transmission code identification unit And a packetizing unit for packetizing the digital data of the digitizing unit switching unit.

Further, the transmission code identification unit includes a timer control circuit and a plurality of identification circuits for different terminal types having different transmission codes, and the plurality of identification circuits sequentially identify the transmission code according to an instruction from the timer control circuit. As long as at least one piece of identification result information is determined, it has a timer control circuit and a function of fixing the digitizing unit selection. In addition, the packetization unit
It has a packet size switching function for fixed length packets and variable length packets.

[0021]

Next, an embodiment of the present invention will be described.
This will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the automatic line identification apparatus of the present invention. This device includes a line handling unit 1 and a switching unit 5. The line handling unit 1 includes a transmission code identifying unit 10, a digitizing unit 2, a digitizing unit switching unit 3, and a packetizing unit 4. Prepare. The transmission code identification unit 10 includes a timer control circuit 11 and an identification circuit 12
And As the transmission line 100, for example, a medium that can be commonly used by various terminals is used. For example, an EIA standard cable 5 is used. As the connection interface, ISO8877 of the ISO standard is used. The transmission code identification unit 10 basically has a function of recognizing transmission codes of various terminals connected to a transmission path and recognizing synchronization of the transmission codes. Further, the transmission code identification unit 10
Has a plurality of identification circuits corresponding to the types of terminals to be connected.

FIG. 2 is a block diagram showing a detailed configuration of the automatic line identification apparatus of the present invention. The transmission code identification unit 10
A plurality of identification circuits 12, for example, four types of identification circuits 1
A configuration including 2a, 12b, 12c, and 12d is shown. The timer control circuit 11 includes an identification switching circuit 1a
And a fixed circuit 1b and a clock circuit 1c. With this configuration, the transmission code identification unit 10 identifies transmission codes of four types of terminals.

Next, the function of each section will be described.

First, the identification circuits 12a, 12b, 12
c and 12d have a function of recognizing the type of transmission code. Specifically, clock synchronization is performed. For example, if the terminal has a LAN interface (10 base-t), the identification circuit 12a recognizes the AMI code, which is the transmission coding method, and confirms the synchronization of the electric signal. If the terminal has an ATM 25M line interface, the identification circuit 12b checks the transmission code N
Recognize the RZI code and confirm the synchronization of the electric signal. If the terminal has a 100 MEther interface, the identification circuit 12c outputs the MLT-
Recognize the three codes and confirm the synchronization of the electric signals. Further, if the terminal has an ISDN interface, the identification circuit 12d recognizes the AMI code that is the transmission code and confirms the synchronization of the electric signal. Temporarily 10base-t
Although the code level is the same between the system and the ISDN interface, it can be determined because the communication speed is different. Further, when it is desired to increase the types of terminals to be connected, it is possible to cope by adding an identification circuit. When synchronization is established, the identification circuits 12a, 12b, 12c, and 12d immediately transmit a synchronization establishment signal 120 to the timer control circuit 11 and the digitizing unit switching unit 3. As the synchronization signal, for example, when synchronization is established, an electrically high-level signal is transmitted, and when synchronization is not established, an electrically low-level signal is transmitted. The synchronization signal is independent for each discrimination circuit, and the digitizing section switching section 3
Will recognize which identification circuit is synchronized.

Second, the function of the timer control circuit 11 will be described below. The timer control circuit 11 includes an identification switching circuit 1a.
And a fixed circuit 1b and a clock circuit 1c. Basically, the timer control circuit 11 performs physical switching between the transmission line 100 and the identification circuits 12a, 12b, 12c, and 12d. The reason for performing the physical switching is a function that takes care not to impair the electrical characteristics of the transmission path. If no synchronization of the identification circuits 12a, 12b, 12c, and 12d has been established, the identification circuits 12a, 12b, 12c, and 12d are switched over at fixed time intervals. Various circuit functions are provided to realize the functions. First, in the clock circuit 1c, the minimum necessary time information for establishing the synchronization of the transmission signal is preset in each of the identification circuits 12a, 12b, 12c, and 12d. The value of the time information is IEEE
Standardized in E802.3, ITV-T, TTC. Based on this time information, the identification circuits 12a, 12b,
By confirming the transmission line 100, 12c and 12d recognize what kind of transmission signal is being transmitted. Next, the fixed circuit 1b includes the identification circuits 12a, 12b, 12
When any one of c and 12d is synchronized, it has a function of fixing the connection between the identification circuit and the transmission line 100 in which the synchronization is established. The fixed circuit 1b also has a function to continue until the synchronization information of the already fixed identification circuit is not established. Next, the identification switching circuit 1a identifies the identification circuits 12a, 12b, 12 based on the switching information of the fixed circuit 1b.
Physical connection and disconnection between the transmission lines 100 and c and 12d are performed.

Third, the digitizing units 2a, 2b, 2
The operation of c and 2d will be described below. Digitizing unit 2
a, 2b, 2c, 2d are identification circuits 12a, 12b, 1
It is provided for 2c and 12d, and has a function of converting a code signal on a transmission line into a binary digital signal.
At the time of digitization, there are various transmission coding methods and transmission speeds, so that a digitizing circuit corresponding to those characteristics is required. As an example, the digitizing unit 2a
Has a function of digitizing a 10Base-t AMI code. The digitizing section 2b has the ATM-2
It has a function of digitizing a 5M NRZ code. The digitizing unit 2c is a 100 base-t ML.
It has a function of digitizing the T-3 code. The digitizing section 2d has a function of digitizing the AMI code of ISDN. Which of the digitizing units operates therein is switched by the control of the digitizing unit switching unit 3. Further, the digitizing units 2a, 2b,
The digital signals digitized by 2c and 2d are sent to the packetizing unit 4 via the digitizing unit switching unit.

Fourth, the operation of the digitizing section switching section 3 will be described below. The digitizing section switching section 3 has a digitizing section switching function for switching the digitizing sections 2a, 2b, 2c, 2d based on the synchronization information from the identification circuits 12a, 12b, 12c, 12d. For example, the identification circuit 12a and the digitizing unit 2a, the identification circuit 12b and the digitizing unit 2b, the identification circuit 12c and the digitizing unit 2
c, assuming that the discriminating circuit 12d and the digitizing section 2d each implement a digitizing function as a set, the discriminating circuit 12d and the digitizing section 2d temporarily recognize the ISDN transmission signal and convert the Assume that
When an ISDN terminal is connected to the transmission line, the switching function of the timer control circuit 11 operates, and the identification circuit 12
The synchronization establishment information of d is notified to the digitizing unit switching unit 3. Since the synchronization information is notified by an individual signal, the digitizing unit switching unit 3 connects the transmission line 100 and the digitizing unit 2d based on the set information determined in advance. Transmission line 1
The connection between 00 and the digitizing unit 2d is maintained until the connection of the ISDN terminal is lost.

Fifth, the function of the packetizer 4 will be described below. The packetizing unit 4 includes each of the digitizing units 2a, 2b,
It has a function of converting digital information from 2c and 2d into a common packet format. The packet size and packet format of the packetizing function of the packetizing unit 4 are not limited, but can be commonly handled by the switching unit 5. For example, ITU-TI. 361-compliant ATM cell format. In addition,
The switching unit 5 has a switching function typified by existing ATMSW and PBX.

[0030]

As described above, with the automatic line identification device of the present invention, by having a plurality of identification circuits, various terminals can be connected with two line-compatible devices without having a plurality of line-compatible devices. The effect is that it is possible.

Also, the provision of the timer control circuit has an effect that the transmission characteristics of the transmission line are not degraded since only one circuit is connected to the transmission line.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a detailed configuration of an embodiment of the present invention.

FIG. 3 is a block diagram illustrating an example of a conventional multiplexer.

FIG. 4 is a diagram showing an operation principle of an example of a conventional standard device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Line corresponding part 10 Transmission code identification part 11 Timer control circuit 1a Identification switching circuit 1b Fixed circuit 1c Clock circuit 12, 12a, 12b, 12c, 12d Identification circuit 2, 2a, 2b, 2c, 2d Digitization part 3 Digitization part Switching unit 4 packetizing unit 5 switching unit 100 transmission path

Claims (10)

[Claims] 1. A line identification device comprising a line corresponding unit accommodating a plurality of various terminals and a switching unit, wherein one line connected to the line corresponding unit handles a plurality of transmission codes, wherein the line corresponding unit comprises: A transmission code identification unit for identifying transmission codes of various terminals; a plurality of digitization units for digitizing the transmission codes; and a plurality of digitization units corresponding to the transmission code identification units based on identification result information of the transmission code identification units. A digitizing unit switching unit that selects a digitizing unit; and a packetizing unit that packetizes digital data of the digitizing unit switching unit and sends the packetized data to the switching unit. A plurality of identification circuits having different codes, an identification switching circuit for physically switching between the plurality of identification circuits and the transmission line, a fixed circuit for fixing after switching, and a clock circuit And a timer control circuit having the plurality of identification circuits, according to an instruction of the timer control circuit, wherein the transmission code sequence identifies the, and the identification result information 1
The line automatic identification device, wherein the timer control circuit and the digitizing unit switching unit are fixed while at least one is determined. 2. The automatic line identification apparatus according to claim 1, wherein said packetizing section has a function of switching a packet size between a fixed length packet and a variable length packet. 3. The transmission code identification unit has a function of recognizing synchronization of the transmission code.
Or the line automatic identification device according to 2. 4. The automatic line identification apparatus according to claim 3, wherein said plurality of identification circuits perform clock synchronization in order to recognize the type of said transmission code. 5. The clock circuit sets in advance, in each of the plurality of identification circuits, minimum time information required for establishing the clock synchronization.
The line automatic identification device according to claim 4. 6. The apparatus according to claim 4, wherein said plurality of identification circuits immediately transmit a synchronization establishment signal to said timer control circuit and said digitizing section switching section when said clock synchronization is established. 6. The automatic line identification device according to 5. 7. The synchronization establishment signal according to claim 6, wherein the synchronization establishment signal is an electrically high level signal, and the synchronization non-establishment signal whose synchronization is not established is an electrical low level signal. Automatic line identification device according to 1. 8. The fixed circuit fixes a connection between a corresponding one of the plurality of identification circuits and the transmission line when clock synchronization of any one of the plurality of identification circuits is established. 8. The automatic line identification device according to claim 4, wherein: 9. The identification switching circuit according to claim 1, wherein the plurality of identification circuits are physically connected to and disconnected from the transmission line based on switching information from the fixed circuit. 8. The automatic line identification device according to any one of 8. 10. The automatic line identification apparatus according to claim 1, wherein said plurality of digitizing units convert the code signal of said transmission path into a binary digital signal.