JPH0530129A - System for selecting signal channel - Google Patents

Abstract

PURPOSE:To qualify a new regular signal channel by analyzing reception cell in which a qualification bit is not qualified in a signal processing part and setting the corresponding qualification bit to be 'real' in a conversion table when the bit is qualified. CONSTITUTION:In an incoming-side exchange 20, the area of an output-side channel number indexed by a reception virtual channel number in which the reception cell is included, and the area of the qualification bit are provided on the conversion table 30 in a header conversion part 21. When the qualification bit indexed by the reception virtual channel number is not qualified, the reception cell is considered to be an emergency signal cell and it is transferred from the header conversion part 21 to a signal processing part 22. When the signal processing part 22 analyzes the emergency signal cell and qualifies it to be the signal, the corresponding qualification bit is set to be 'true' in the conversion table 30. Thus, the normal signal channel can newly be set when a regular signal can be received since any virtual channel number whose qualification bit is 'doubtful' can be used as a signal channel for emergency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an asynchronous transfer mode (AT
The present invention relates to a signal channel selection method for selecting a signal channel between adjacent stations among the signaling methods of the switching network that employs the multiplexing method called M).

[0002]

2. Description of the Related Art Conventionally, a so-called fixed channel allocation method has been proposed as this type of signal channel selection method, in which a virtual channel number (VIC) for a signal channel set between switching stations of a switching station is determined in advance and fixedly used. It had been.

[0003]

The above-mentioned signal channel selection system is a fixed channel allocation system, and since the signal channels between adjacent stations of all ports in the network are fixedly determined, the VCI value in the signal cell is However, there was a drawback that when it was destroyed during transfer and had a different value, transmission and reception of signals between adjacent stations could not be done at all.

It is an object of the present invention to provide the above-mentioned drawbacks by providing each exchange with a means for detecting all the received cells for which no output side channel has been set by transferring them to the signal processing means and for detecting the non-arrival of signals. It is to provide a signal channel selection method that eliminates the problem.

[0005]

The basic structure of a signal channel selection system according to the present invention is a signal channel selection system for selecting a signal channel to be set between exchanges adopting an ATM (asynchronous transfer mode) multiplexing system. In the conversion table in the header conversion unit installed between the exchange unit and the switch unit at each input port, in addition to the area of the output side channel number indexed by the reception virtual channel number included in the reception cell, the area of the authentication bit If the authentication bit indexed by the received virtual channel number is not authenticated, the received cell is regarded as an emergency signal cell and transferred from the header conversion unit to the signal processing unit, and the signal processing unit receives the emergency signal cell. When the transmission channel is analyzed and authenticated as a signal, this transmission channel is regarded as a normal signal channel, and the corresponding conversion table Having means for the bit to "true".

Further, one specific configuration added to the above basic configuration is that after the exchange establishes the normal signal channel for the emergency signal cell in the previous period, a predetermined signal is periodically sent to this channel from the originating exchange. The present invention is to have means for transmitting a cell, detecting the normal signal channel as a failure, and executing the signal channel selection process again when the destination exchange cannot regularly receive the signal cell.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention.

As shown in FIG. 1 (A), the originating exchange 10
Is connected to the destination exchange 20 by a multiplexing line 40 by ATM (asynchronous transfer mode).

The originating exchange 10 connects the communication line for each call from the switch unit 11 to the multiplexing line 40 via the signal cell insertion unit 14, while the communication processing unit 12 causes the signal cell insertion unit 1 to be connected.
Connect the signal channels via 4.

The signal channel on the multiplex line 40 is formed by a signal cell to which one preset virtual channel number is assigned. This cell is generated by the signal cell insertion unit 14.

The destination exchange 20 analyzes the cells received by the header converter 21 and distributes the received cells to the signal processor 22 and the switch 24.

The header converter 21 has a conversion table 30, and this conversion table 30 has an output side channel number 32 and an authentication bit 33 in an area corresponding to a reception virtual channel number (VCI) 31.

Both the signal processing unit 12 of the originating exchange 10 and the signal processing unit 22 of the terminating exchange 20 have heartbeat circuits 13 and 23 to monitor the line.

The header converter 21 of the destination exchange 20 has a conversion table 30.

FIG. 1B is a block diagram showing an example of the conversion table 30. As shown in the figure, the conversion table 30 displays the virtual channel number (VC
I) 31 has an area for an output side channel number 32 and an authentication bit 33.

The area of the output side channel number 32 is the output port physical number and the virtual channel number on the output port. Further, for the inter-station signal, a route instruction to the signal processing unit 22 or the control unit (not shown) is recorded.

The area of the authentication bit 33 is the signal processing section 22.
When authenticates the reception cell with the user information channel or the normal signal, the notification is received and "true" is recorded in the position corresponding to the reception virtual channel number (VCI).

When the authentication bit 33 is "suspect" other than "true", the header conversion section 21 transfers the received cell to the signal processing section 22.

Therefore, in the case of a normal signal channel failure,
Or, at the time of initial startup when the normal channel number is undecided,
Since the authentication bit 33 is “suspicious”, when the received normal signal cell is determined to be a normal signal by the signal processing unit 22, the conversion table 30 receives the notification and receives the authentication bit 33.
Change the "suspect" of to "true".

As described above, since any virtual channel number of the authentication bit "suspect" can be used as an emergency signal channel, if a normal signal can be received, a new normal signal channel can be set.

Further, when the normal signal channel established is delayed due to some trouble in the reception of the normal signal, the signal processing units 12 and 22 have heartbeat circuits 13 and 23 for early detection. The heartbeat circuits 13 and 23 periodically send out signal cells from the originating heartbeat circuit 13 by a predetermined virtual channel number (VCI) of the multiplexing line 40, and the destination heartbeat circuit 23 carries out this regular period. When a specific signal cell cannot be received, a failure of the normal signal channel is detected and a predetermined operation process is executed.

[0022]

As described above, according to the present invention, the authentication bit "true" is recorded in the virtual channel for normal use,
Virtual channel to receive is "suspicious" except authentication bit "true"
Then, one of all virtual channels with the authentication bit “suspect” is selected and converted to the authentication bit “true”, and all unauthenticated virtual channels can be used as an emergency channel. The number can be made variable, and there is an effect that a signal channel can be set separately even if a specific virtual channel number becomes an obstacle.

Further, by periodically transmitting the signal cell to the normal signal channel of the specific virtual channel number, there is an effect that the abnormality can be detected even if the specific channel becomes an obstacle.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a signal channel selection system of the present invention.

[Explanation of symbols]

10, 20 Switch 11, 24 Switch section 12, 22 Signal processing section 13, 23 Heartbeat circuit 14 Signal cell insertion section 21 Header conversion section 30 Conversion table 31 Virtual channel number (V
CI) 32 Output side channel number 33 Authentication bit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication H04Q 11/04 303 Z 8843-5K 9076-5K H04Q 11/04 R

Claims (2)

[Claims] 1. In a signal channel selection system for selecting a signal channel to be set between exchanges adopting an ATM (asynchronous transfer mode) multiplexing system, the exchange is installed between each input port and a switch section. In the conversion table in the header conversion unit, an authentication bit area is provided in addition to the output side channel number area indexed by the reception virtual channel number included in the reception cell, and the authentication bit indexed by the reception virtual channel number is not authenticated. In this case, the received cell is regarded as an emergency signal cell and transferred from the header conversion unit to the signal processing unit. When the signal processing unit analyzes the emergency signal cell and authenticates it as a signal, this transmission channel is changed to the normal signal channel. And a signal channel characterized by having means for setting the corresponding authentication bit in the conversion table to "true". Selection method. 2. After establishing the normal signal channel for the emergency signal cell in the previous term, a predetermined signal cell is periodically sent from the originating exchange to this channel, and the destination cell exchanges this signal cell periodically. 2. The signal channel selection system according to claim 1, further comprising means for detecting the normal signal channel as a failure when the signal cannot be received and executing signal channel selection processing again.