JP2000270119A - Communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform communication by the sum of the communication speed in a plurality of digital private lines of ISDN using the plurality of lines. SOLUTION: This communication apparatus 1 is provided with line control parts 104 and 105 for housing the plurality of digital private lines, a bulk control part 106 and a control part 101. Under the control of the control part 101, upon activating the communication or upon receiving a test pattern PB, the bulk control part 106 sends out the test pattern PB to the plurality of lines, respectively. Also, based on the reception timing of the test pattern PB received through the plurality of lines, respectively a signal propagation time difference between the plurality of lines is detected and the signals received through the respective plural lines are synchronized with each other corresponding to the time difference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication apparatus for accommodating a plurality of digital dedicated lines and performing communication at the sum of the communication speeds of the accommodated plurality of lines.

[0002]

2. Description of the Related Art Conventionally, TA (terminal adapter)
Such communication terminals using ISDN are known. As this type of communication device, JP-A-4-57436, JP-A-5-227245, or JP-A-6-227245.
As shown in Japanese Patent Publication No. 276261, two channels B1 and B2 (communication speed: 6
4 kbps) to use up to 128
There are communication devices that can communicate at kbps. In these communication devices, a sequence for establishing synchronization of the B1 channel and the B2 channel is executed by using a call setting sequence as a trigger, thereby establishing synchronization of the two channels B1 and B2.

[0003]

By the way, a line for an ISDN circuit-switched service requires a longer communication time.
It costs much (line usage fee). Therefore,
When the communication time is long, it may be more advantageous to use a digital leased line whose cost is constant regardless of the communication time. In particular, when communication is performed using a plurality of lines (each line includes two B channels), the tendency becomes remarkable.

[0004] When communication is performed at the sum of the communication speeds of a plurality of lines using a plurality of digital dedicated lines (each line includes two B channels), the communication between the B channels in the above-described prior art is performed. As with the synchronization, it is necessary to establish the synchronization between the multiple lines. However, since the digital leased line is always in a connected state and the call setting sequence is not performed, the call setting sequence cannot be used as a trigger for establishing synchronization between a plurality of lines as in the related art. .

Therefore, the conventional technique cannot be applied to the establishment of synchronization between a plurality of digital leased lines (each of which includes two B channels). Communication using the sum of the communication speeds of the plurality of lines using a plurality of lines cannot be realized.

The present invention has been made in view of the above circumstances, and an object of the present invention is to accommodate a plurality of digital leased lines, establish synchronization between the accommodated plurality of lines, It is an object of the present invention to provide a communication device capable of performing communication at the sum of the communication speeds.

By the way, if a plurality of lines are synchronized and used for communication irrespective of a line for an ISDN circuit switching service or a digital leased line, any one of the plurality of lines used for communication may fail. Occurs, even if the remaining lines are normal, communication cannot be performed at all. On the other hand, if a failure occurs in any of the multiple lines used for communication, it is conceivable to immediately start communication using the remaining normal lines. Given the possibility of a transient and immediate recovery, in the event of such a failure, immediately eliminate the failed line,
Performing communication using the remaining normal lines may rather degrade communication efficiency. On the other hand, if the fault that occurred on the line is not transient, continuing to use the line on which the fault has occurred degrades communication efficiency.

Accordingly, the present invention provides a communication device capable of resuming communication in a form that is not likely to degrade communication efficiency when the communication occurs on any of a plurality of lines used for communication. Is also an issue.

[0009]

In order to achieve the above object,
The present invention is a communication device for accommodating a plurality of ISDN digital dedicated lines and performing communication by synchronizing the accommodated plurality of lines, and a line control means for accommodating a plurality of digital dedicated lines, To initiate communication, and
Means for executing a predetermined signal sequence for transmitting and receiving a test signal via the line with another communication device connected via the plurality of lines when receiving a test signal from the line, the signal sequence Includes a sequence for transmitting and receiving a specific test signal via each of the plurality of lines, wherein the communication device further includes receiving the specific test signal received via each of the plurality of lines during the signal sequence. Time difference detecting means for detecting a signal propagation time difference between the plurality of lines based on timing, and synchronizing signals received via each of the plurality of lines with each other according to the signal propagation time difference detected by the time difference detecting means. A synchronizing means, a buffer for holding a signal received through each of the plurality of lines, and a time difference detecting means In accordance with the signal propagation time difference out,
Synchronizing means having buffer control means for controlling the buffer, and a signal synchronized by the synchronizing means, so that signals received via each of the plurality of lines are simultaneously output from the buffer. Matching means for assembling in a predetermined order to form a signal and transmitting the signal to the communication terminal, dividing the signal transmitted from the communication terminal into a plurality of signals, and allocating the signals to the plurality of lines according to a predetermined standard and transmitting the signals; And a communication device comprising:

[0010] According to such a communication device, one of the communication devices that starts the communication transmits and receives a test signal to and from the other communication device connected via each of the plurality of lines, in response to the start of the communication. Is executed. On the other hand, the other communication device also executes a predetermined signal sequence for transmitting and receiving a test signal to and from the one communication device, triggered by reception of a test signal transmitted from one communication device.

In this signal sequence, a specific test signal is transmitted / received between the two communication devices via each of the plurality of lines, thereby detecting a signal propagation time difference between the plurality of lines. The signals received via the plurality of lines are synchronized with each other.

That is, according to such a communication device,
Irrespective of the call setting sequence, a predetermined signal sequence for transmitting and receiving a test signal can be used as a trigger to establish synchronization between a plurality of lines and enable communication using the synchronized plurality of lines.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below.

FIG. 1 is a schematic configuration diagram of a communication system to which one embodiment of the present invention is applied.

As shown in the figure, in the communication system of this embodiment, communication devices 1a and 1b (hereinafter, also simply referred to as communication terminals 1) to which communication terminals (DTEs) 3 are connected, respectively,
They are connected to each other via a high-speed digital dedicated line 2 of SDN.

Each communication device 1 accommodates two lines from the high-speed digital leased line 2 (the lines 4a and 4b for the communication terminal 1a, and the lines 5a and 5b for the communication terminal 1b). Communication is performed at the sum of the communication speeds of

FIG. 2 shows a schematic configuration of the communication device 1.

As shown in the figure, a communication device 1 includes a DTE interface unit 102 for exchanging information with a communication terminal 3 and line control units 104 and 105 for accommodating two high-speed digital leased lines 2. , Bulk controller 106, bulk controller 106 and line controller 10
4 and 105, via a communication port 103 for exchanging test patterns and a control bus 107,
A control unit 101 for integrally controlling each component of the communication device 1 and an alarm transmission unit 10 for transmitting an alarm
9 and a display unit 108 for displaying various information.

The bulk control unit 106 includes the line control unit 10
The signal transmitted from the communication partner via each of the two lines accommodated by the communication lines 4 and 105 is synchronized with each other, and the signals from the synchronized two lines are assembled in a predetermined order to form a signal. The data is transmitted to the communication terminal 3 via the communication terminal 102. Also, the DTE interface unit 10
The signal transmitted from the communication terminal 3 via the communication terminal 3 is divided into a plurality of signals.
4 and 105 are assigned to the two lines accommodated and transmitted to the communication partner.

FIG. 3 shows a schematic configuration of the bulk control unit 106.

As shown in the figure, the bulk control unit 106
A delay time detector 601 for detecting a signal propagation time difference (delay time) between two lines accommodated by the line controllers 104 and 105; and a line accommodated by the line controller 104 (4a for the communication device 1a, 5a for device 1b)
Buffer 603 for temporarily holding a signal from a line (4b in the case of the communication device 1a and 5b in the case of the communication device 1b) accommodated by the line control unit 105. And the line control unit 104,
And a speed matching unit 602 for communicating with a communication partner based on the sum of the communication speeds of the two lines accommodated by the network 105.

The delay time detecting unit 106 is connected to the communication port 10
6, two lines (4a and 4b in the case of the communication device 1a,
In the case of b, test patterns for detecting the delay time are transmitted to each of 5a and 5b). In addition, a test pattern for delay time detection transmitted from each communication partner via each of the two lines accommodated by the line control units 104 and 105 is received via the communication port 106, and the test pattern is received according to the arrival time.
A signal propagation time difference (delay time) between lines is detected.

FIG. 4 shows an example of signal reception timing in the communication device 1 on the receiving side.

Here, FIG. 4A shows the line control unit 104,
The signal reception timing of one of the two lines accommodated by 105 is shown, and FIG. 4B shows the signal reception timing of the other. B1, B2
Is a data channel included in each line.

The signal transmitted on each line has a difference in signal propagation time due to a difference in a line route or the like. Therefore, a difference occurs in the reception timing as shown in the figure. The delay time detecting unit 106 receives a signal from the line control unit 10
The signal propagation time difference (delay time) between the two lines is detected based on the reception timing (arrival time) of the test pattern for delay time detection transmitted via each of the two lines accommodated by the lines 4 and 105. Then, the control unit 101 is notified of the detected delay time. In response, the control unit 101
Is the buffer provided on the side of the line (the line having the reception timing shown in FIG. 4A in the example shown in FIG. 4) on which the test pattern for delay time detection arrives first among the buffers 603 and 604. Is instructed to hold the input signal for a period indicated by the delay time.

The buffers 603 and 604 are provided in the control unit 101.
The input signal is held for a period designated by. If there is no instruction, the input signal is output immediately. By doing so, the signals transmitted via the two lines accommodated by the line controllers 104 and 105 are synchronized with each other. That is, the buffers 603 and 604 function as buffers that absorb the signal propagation time difference between the two lines accommodated by the line controllers 104 and 105.

The speed matching unit 602 includes buffers 603 and 6
Signals transmitted from each of the two lines accommodated by the line control units 104 and 105 via the line controller 04 are assembled in a predetermined order to generate one signal. Further, the signal transmitted from the communication terminal 3 via the DTE interface unit 102 is divided into signals of the total number of channels (4 channels) of the two lines accommodated by the line control units 104 and 105, and these are divided. In accordance with a predetermined criterion, each of the two lines accommodated by the line control units 104 and 105 is assigned and transmitted. In this way, two lines accommodated by the line controllers 104 and 105 are used, and communication is performed with the communication partner at the sum of the communication speeds of these lines.

FIG. 5 is a diagram for explaining the operation principle of the speed matching unit 602.

FIG. 5 (a) shows signals exchanged with the DTE interface unit 102, that is, the communication terminal 3, and FIG. 5 (b) shows the line control unit 104,
5 shows a signal exchanged with a line accommodated by one of them, and FIG. 5C shows a signal exchanged with a line accommodated by the other. B1 and B2 are data channels included in each line.

Referring to FIG. 5, first, line control unit 104,
An operation principle in the case where signals sent from each of the two lines accommodated by 105 are assembled in a predetermined order to generate one signal will be described.

The speed matching section 602 converts the signals shown in FIGS. 5B and 5C into a signal Di included in the B1 channel of the line shown in FIG. 5B → the line shown in FIG. 5B. Of B
The signal Di + 1 included in two channels → the signal Di + 2 included in the B1 channel of the line shown in FIG. 5C → the signal Di + 3 included in the B2 channel of the line shown in FIG. 5C. Assemble with Then, every time one round is made, i is incremented (i = i + 4), and the above processing is repeated. By doing so, the signal shown in FIG. 5A is generated. This signal is transmitted to the communication terminal 3 via the DTE interface unit 102.

Next, the signal transmitted from the communication terminal 3 is divided into a plurality of signals via the DTE interface unit 102, and the line control unit 104
An operation principle in the case of assigning to each channel of the two lines accommodated by 105 will be described.

The speed matching unit 602 time-divides the signal shown in FIG. 5A at appropriate time intervals, and
i to the B1 channel of the line shown in FIG.
To the B2 channel of the line shown in FIG.
To the B1 channel of the line shown in FIG.
Are assigned to the B2 channels of the line shown in FIG. Then, after one round, i is incremented (i =
i + 4), and the above processing is repeated. In this way, the signals shown in FIGS. 5B and 5C are generated. These signals are sent to the corresponding lines via the line controllers 104 and 105.

Next, the operation of the communication device 1 will be described.

FIG. 6 is a flowchart for explaining the operation of the communication device 1.

First, when the power is turned on, a line used for communication is set as a used line according to the initial setting (step J1). Here, it is assumed that two lines accommodated by the line accommodation units 104 and 105 are set as used lines.

Next, the control unit 101 controls the ISDN layer 1 (TTC (Telecommunication Technology Committe
e) Standard I.D. 430, I.P. The monitoring of 430a) is started. Then, it waits for layer 1 to be established for each used line (step J2), and after establishment, shifts to the next step.

Next, the control unit 101 transmits a communication start indication signal (an ER signal in an interface conforming to V.24 and V.35 of the TTC standard, an X signal of the same standard) from the communication terminal 101 via a DTE interface unit 102. 21 is turned on, or a negotiation start signal (test pattern P described later) is turned on.
Wait for receiving 1) (step J3), and move to the next step. In each of the steps after step J3, the control unit 101 continues to monitor the will display signal. When the will display signal is turned off, the control unit 101 controls so as to immediately return to step J3.

Next, the control unit 101 controls each unit so that negotiation processing for establishing a communication route with a communication partner is performed for each used line. And
Wait for the negotiation to end (step J
4) After completion, move to the next step.

In the following steps, the control unit 1
01 monitors the input of an instruction for synchronization establishment processing from the communication terminal 3 and, when the instruction is input, controls to return to step J4 immediately.

Next, the control unit 101 controls the bulk control unit 10
6 is instructed to perform bulk synchronization establishment processing between the used lines. In response to this, the bulk control unit 106 performs synchronization establishment processing between the used lines. The control unit 101 waits for the completion of the bulk synchronization establishment (step J5), and after the synchronization establishment, the communication is started by the communication terminal 3 (step J5).
6). In addition, in each step after step J5,
The control unit 101 monitors the reception of a negotiation start signal (a test pattern P1 described later), and when receiving the negotiation start signal, controls to return to step J4 immediately.

The control unit 101 continues to monitor the layer 1 in each step after the step J3, and when the disconnection of the layer 1 is detected during the execution of the step J3, the control unit 101 returns to the layer 1 establishing processing of the step J2. Is controlled. Further, when the disconnection of the layer 1 is detected during the execution of the above steps J4, J5, and J6, the failure processing (step J7) is executed, and then, according to the result, the step J2 is executed.
Is controlled so as to return to the layer 1 establishment process of the above or the negotiation process of step J4.

Next, the negotiation processing performed in step J4 shown in FIG. 6 will be described. Here, as described above, the negotiation process is a process for establishing a communication route with a communication partner, and a process of determining whether data communication using a data channel of a used line is possible. It is.

FIG. 7 is a flowchart for explaining a negotiation process performed in the communication device 1. This flow is performed sequentially or simultaneously for each of the lines used in the communication device that starts communication. That is, when two lines accommodated by the line accommodating units 104 and 105 are set as communication lines in the communication apparatus 1, negotiation processing is performed on each of the two lines sequentially or simultaneously. It is more preferable that the negotiation for a certain line is performed for each of the two B channels of the line, but it may be performed for only one B channel.

Hereinafter, the details of the negotiation for one line will be described using the line accommodated by the line accommodating unit 104 as an example.

First, the control unit 101 controls the communication port 103
And the line control unit 10 via the delay time detection unit 601.
The transmission of the test pattern P1 for negotiation is started to the line accommodated by No. 4 (step S
1). Next, it waits for a test pattern P1 for negotiation to be sent from the communication partner (the other communication device 1) to the line accommodated by the line control unit 104 (step S2). Next step S
3, but here, the test pattern P1 has already been set.
Has been sent, the process proceeds directly to the next step S3.

Here, if the communication device 1 is a device that starts communication, that is, a device whose ER / C is turned on in step J3 of FIG. 6, the communication device 1 is used in step S1. In accordance with the setting of the line, the negotiation test pattern P1 is transmitted to the line accommodated by the line control unit 104, and the negotiation test pattern P1 is transmitted from the communication partner (the other communication device 1) in step S2. I will wait for you to come. On the other hand, if the communication device 1 is a device on which communication is activated, that is, a device that has received the negotiation start signal in step J3 of FIG. 6, the line accommodated by the line control unit 104 in step S1. When the test pattern P1 for negotiation is received, the test pattern P1 is transmitted to this line when the test pattern P1 for negotiation is received. Since the test pattern P1 has already been transmitted when step S2 is executed, the next step S3 Will go on.

Next, the control unit 101 proceeds to step S
In step 3, the timer T1 is started (step S3), and waits until the timer T1 times out. This timer T1
Means that the negotiation test pattern P1 started to be transmitted in step S1 is transmitted to the communication partner (if a failure occurs).
This is to ensure that it arrives reliably.

Next, when the timer T1 expires, the control section 101 stops sending the negotiation test pattern P1 (step S5). Then, via the communication port 103 and the delay time detecting unit 601,
The transmission of the test pattern P2 for negotiation to the line accommodated by the line control unit 104 is started (step S6).

Next, the control unit 101 activates the timer T2 (step S7), and sets the line accommodated by the line control unit 104 until the timer T2 times out.
Test pattern P2 for negotiation from communication partner
Is sent (steps S8 and S9), and if sent, the process proceeds to the next step S10. However, if the test pattern P2 has already been sent, the process proceeds to the next step S10. move on.

The timer T2 is for re-executing the negotiation process when a failure occurs and the negotiation test pattern P2 transmitted from the communication partner cannot be received. If the negotiation test pattern P2 cannot be received from the communication partner before the timer T2 expires, the process returns to step S1, and the negotiation process is restarted from the beginning.

Next, at step 10, the control unit 10
1 starts the timer T3 (step S10) and waits for the timer T3 to time out (step S11).
This timer T3 is, like the timer T1, the test pattern P for negotiation which has started transmission in step S6.
No. 2 is for ensuring that the communication partner reaches the communication partner (if a failure occurs).

Next, when the timer T3 times out, the control section 101 stops sending the negotiation test pattern P2 (step S12). then,
Via the communication port 103 and the delay time detection unit 601, the transmission of the negotiation test pattern P3 to the line accommodated by the line control unit 104 is started (step S13).

Next, the control unit 101 activates the timer T4 (step S14), and sets a test pattern for negotiation from the communication partner to the line accommodated by the line control unit 104 before the timer T4 times out. Wait for P3 to be sent (steps S15, S1
6) If sent, go to the next step S17.
However, here, if the test pattern P2 has already been sent, the process directly proceeds to the next step S17. This timer T4, like the timer T2, causes some trouble,
This is for re-executing the negotiation process when the negotiation test pattern P3 transmitted from the communication partner cannot be received. Timer T4
If the negotiation test pattern P3 cannot be received from the communication partner by the time up, the process returns to step S1, and the negotiation process is restarted from the beginning.

Next, in step S17, the control unit 101
Starts the timer T5 (step S17), and starts the timer T5.
Wait for time-out of 5 (step S18). This timer T5 is the same as the timers T1 and T3 in the step S1.
This is to ensure that the negotiation test pattern P3 started to be transmitted in step 3 reaches the communication partner (if a failure occurs) without fail.

Next, when the timer T5 times out, the control section 101 stops sending the negotiation test pattern P3 (step S19). then,
The timer T6 is activated (step S20), and waits until the negotiation test pattern P1 is sent from the communication partner to the line accommodated by the line control unit 104 before the timer T6 times out (step S20). S21, S22). When a failure occurs and the negotiation test pattern does not reach the communication partner (the other communication device 1), the communication partner restarts the negotiation process from the beginning, and the timer T6 starts the negotiation test pattern P1. Is transmitted again, the negotiation process is performed again from the beginning in the same device.

If the negotiation test pattern P1 is received from the communication partner before the timer T6 times out, the process returns to step S1 and the negotiation process is restarted from the beginning. On the other hand, if the negotiation test pattern P1 is not received from the communication partner before the timer T6 expires, the establishment of negotiation is declared (step S23), and the process ends.

In the above flow, the timer T1
The time up to T6 may be set to be longer than that in consideration of the signal propagation time when the high-speed digital dedicated line 2 is used.

FIG. 8 shows a flow of a test pattern for negotiation in the flow shown in FIG.

As shown in FIG. 8, when the data channel of a certain line between the communication device 1a and the communication device 1b is normal in both directions, each sequence is started by the test pattern P1 transmitted by the communication starting side. In the communication device, negotiation test patterns P1 to P1
The transmission and reception of P3 is performed for each of the lines used in the device that starts the communication, and negotiation of these lines is established.

On the other hand, for example, the data channel from communication device 1b to communication device 1a is normal,
When the data channel from the communication device 1a to the communication device 1b is disconnected, as shown in FIG. 9, the negotiation test pattern transmitted from the communication device 1a
, The communication device 1b that has started the communication continues to transmit the test pattern P1, and the communication device 1a repeats the negotiation process. Therefore, when such an event is detected, predetermined abnormal processing is performed.

Next, the bulk synchronization establishment processing performed in step J5 shown in FIG. 6 will be described. Here, the bulk synchronization establishment processing is, as described above, when the establishment of negotiation is declared for each of the lines set as the used lines in the device that activates the communication, and in each of the communication devices, This is a process performed to synchronize signals transmitted from a communication partner (another communication device 1) through the buffer 603 or the buffer 60.
4 sets the time to hold the signal sent via the corresponding line.

FIG. 10 shows the communication device 1a and the communication device 1
It is a flowchart for demonstrating the bulk synchronization establishment process performed between b. Here, the device that starts communication is the communication device 1a, and the lines 4a and 4b accommodated in the line control units 104 and 105 are set as the used lines in the communication device 1a, and negotiation processing is established for these lines. An example will be described below.

First, the processing of the communication device 1a in this case will be described.

First, the bulk control unit 106 of the communication device 1a
The delay time detecting unit 601 of the line 4a accommodated in the line control units 104 and 105 via the communication port 103,
4b, the test pattern PB for detecting the delay time is transmitted at the same timing (step S101). next,
Lines 4a and 4b accommodated in line control units 104 and 105
The test pattern PB for delay time detection transmitted from the communication device 1b via each of them is received via the communication port 103 (step S102).

Next, the delay time detecting section 601 detects the signal between the line 4a and the line 4b based on the reception timing of the test pattern PB for delay time detection sent from the communication device 1b on each of the lines 4a and 4b. The propagation time difference (delay time) is calculated, and this is notified to the control unit 101 (step S103).

In response to this, the control unit 101 sets the buffer provided on the line side of the buffers 603 and 604, which has received the test pattern PB for delay time detection transmitted from the communication device 1b first, to the Control is performed so that the signal received from the corresponding line is held for the delay time obtained in step S103 (step S104).

Then, the control unit 101 communicates with the communication port 1
An end signal is sent to the lines accommodated in the line controllers 104 and 105 via the communication device 03 (step S105), and then the communication device 1b waits for an end signal to be sent (step S106).

When the termination signal is received from the communication device 1b, the processing is terminated and the communication terminal 3 is notified of the connection.
The state shifts to a state where communication by the communication terminal 3 is possible. That is, the signal transmitted from the communication terminal 3 via the DTE interface unit 102 is divided by the speed matching unit 602 and assigned to each channel of the lines 4a and 4b accommodated by the circuit control units 104 and 105. Also, the line 4a accommodated by the circuit control units 104 and 105,
4b, one of the signals sent through each
After being time-delayed by the corresponding buffers 603 and 604 and synchronized with the other, the speed matching unit 602 causes the lines 4a,
4b is assembled into one signal and sent to the communication terminal 3 via the DTE interface unit 102.

Next, the processing in the communication device 1b will be described.

The delay time detecting section 60 of the bulk control section 106
1 is the line 5 accommodated in the line controllers 104 and 105
The test pattern PB for detecting the delay time sent from the communication device 1a through the communication port 10a through the communication port 10a.
3 (step S201).

Next, the delay time detecting section 601 detects the signal between the line 5a and the line 5b based on the reception timing of the test pattern PB for detecting the delay time sent from the communication device 1a on each of the lines 5a and 5b. The propagation time difference (delay time) is calculated, and this is notified to the control unit 101 (step S202).

In response to this, the control unit 101 changes the buffer provided on the line side of the buffers 603 and 604, which has received the test pattern PB for delay time detection transmitted from the communication device 1a first, Control is performed so that the signal received from the corresponding line is held for the delay time obtained in step S202 (step S203).

Thereafter, the delay time detecting section 601 sends the test pattern PB for detecting the delay time at the same timing via the communication port 103 to each of the lines 5a and 5b that have received the test pattern PB from the communication device 1a. (Step S204).

Then, the control unit 101 sets the communication device 1a
Wait for an end signal to be sent (step S20).
5). When the end signal is received, the end signal is sent to the lines accommodated in the line controllers 104 and 105 via the communication port 103 (step S206), and the processing is ended to notify the communication terminal 3 of the connection. Then, the state shifts to a state where communication by the communication terminal 3 is possible. That is, the signal sent from the communication terminal 3 via the DTE interface unit 102 is divided by the speed matching unit 602 and
4 and 105 are allocated to each channel of the lines 5a and 5b accommodated. Also, the circuit control units 104, 10
One of the signals transmitted through each of the lines 5a and 5b accommodated by the
03, 604, and after synchronizing with the other, the signal included in each channel of the lines 5a, 5b is assembled into one signal by the speed matching unit 602, and the communication terminal 3 is connected via the DTE interface unit 102. Send to

Next, the failure processing performed in step J7 in FIG. 6 will be described.

FIG. 11 is a flowchart for explaining the fault processing performed in the communication device 1.

In this process, a failure detection counter Ci provided for each line i set as a currently used line and a timer Ki are used.

As shown in the figure, in this processing, the control unit
When the layer 1 disconnection of the line i is detected, first, it is checked whether or not the timer Ki is running (step K1). If not, the timer Ki is started (step K3) and the fault detection counter Ci is cleared. After that (Step K4), the fault detection counter Ci is incremented by one (Step K5), and the threshold value that has been initially set is compared with the value of the fault detection counter Ci (Step K6), and the value of the fault detection counter Ci is calculated. Is larger than the threshold, the process proceeds to step K8.
Proceed to.

On the other hand, if the timer Ki is running (step K1), it is first checked whether or not the timer Ki that times out at the initially set time has timed out (step K2). The timer Ki is restarted (step K3), and the failure detection counter C
After clearing i (step K4), the failure detection counter C
i is incremented by 1 (step K5), and the threshold value which has been initialized is compared with the value of the failure detection counter Ci (step K6). If the value of the failure detection counter Ci is larger than the threshold value, the process proceeds to step K8. If smaller, go to step K7.

Here, assuming that a value greater than or equal to 2 is set as the threshold value, the fault detection counter Ci becomes 1 in both of the above two cases, so that the process proceeds to step K7. Then, in step K7, the processing is performed in step J of FIG.
Control to return to 2 is performed.

On the other hand, if the timer Ki is running (step K1) and the timer Ki has not timed out (step K2), the fault detection counter CI is incremented by 1 (step K5) and initialized. The set threshold value is compared with the value of the failure detection counter Ci (step K).
6) If the value of the failure detection counter Ci is larger than the threshold value, the process proceeds to step K8; if smaller, the process proceeds to step K7.

When the process proceeds to step K7, control is performed to return the process to step J2 in FIG.

On the other hand, when the process proceeds to step K8, first, an alarm is sent out via the alarm sending unit 107 (step K8), and the display unit 108 displays that the line i has a serious fault (step K8). K9).

Then, the used line is changed from the used line currently set as the used line to the line other than the line i in which the layer 1 disconnection is detected (step K10). Then, control is performed to return the processing to step J4 in FIG. 6 (step K11).

As a result of the above processing, as shown in FIG.
Timer Ki for any line included in the used line
Until a layer disconnection exceeding the threshold value is detected within the timeout period of (1), that is, until the frequency of occurrence of the layer 1 disconnection of any line becomes equal to or higher than a predetermined level, the layer 1 establishment processing of step J1 in FIG. The process is repeated to perform communication using the set use line. However, if the frequency of occurrence of layer 1 disconnection of any line becomes equal to or higher than a predetermined level, this line is excluded from the use line. The processing is performed such that the processing from the negotiation processing in step J3 of FIG. 6 is performed, and the communication is performed using a line other than the line in which the occurrence frequency of the layer 1 disconnection is equal to or higher than a predetermined level as a new used line. Will be done.

The embodiment of the present invention has been described above.

In the above-described embodiment, the case where two high-speed digital dedicated lines are accommodated and communication is performed at the sum of the communication speeds of the two lines has been described. However, the present invention is not limited to this. INDUSTRIAL APPLICABILITY The present invention is applicable to a communication device that accommodates a plurality of digital dedicated lines and performs communication at the sum of the communication speeds of the plurality of lines.

In the above embodiment, the line used is changed by the processing of the failure processing (step J7 in FIG. 6).
In the case where such a change of the used line is not performed, if it is guaranteed that the same line is set as the used line in both communication devices, whether the negotiation of all the used lines has been established in both devices. Since it is possible to recognize whether or not the negotiation of all the lines in use has been established, the bulk synchronization process shown in FIG. 10 may be started from any device that has recognized that the negotiation has been established. That is, the device that first transmits the test pattern PB
Either device may be used. However, in this case, in the negotiation process, it is desirable to determine the device that starts the bulk synchronization process.

In the negotiation process, the line to be used may be determined between the two devices, or one device may notify the other device.
In both devices, it is possible to recognize whether or not negotiation of all used lines has been established. Similarly, the bulk synchronization processing shown in FIG. It may be started.

Furthermore, in the above embodiment, the normality of each line is checked by performing a negotiation process for each accommodated line prior to the bulk synchronization establishment process. However, instead of the negotiation process, after the bulk synchronization establishment process, in a state where communication is performed between the communication terminals, for example, in a signal transmitted on each line, the communication device allocates a data bit uniquely used by the communication device, In the communication device, the normality of each line can be checked by detecting the data bit. Further, in the communication device, scrambling / descrambling of a signal included in the data channel of each line accommodated by the communication device is performed between the communication device and a communication terminal which is a communication partner, and a communication terminal connected to the communication device performs It is also possible to check the normality of each line by confirming that the communication data is normal. In these cases, when a line abnormality is detected, it is preferable to perform the bulk synchronization establishment process again.

Further, the change of the used line due to the failure processing is applied not only when a plurality of digital leased line lines are synchronized and used, but also when a plurality of ISDN line switching service lines are synchronized and used. be able to.

[0093]

As described above, according to the present invention,
A communication device capable of accommodating a plurality of digital dedicated lines, establishing synchronization between the accommodated plurality of lines, and performing communication at the sum of the communication speeds of the plurality of lines can be provided. Further, it is possible to provide a communication device capable of restarting communication in a form that is not likely to degrade communication efficiency when any of a plurality of lines used for communication occurs.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a communication system to which an embodiment of the present invention is applied.

FIG. 2 is a schematic configuration diagram of the communication device 1 shown in FIG.

FIG. 3 is a schematic configuration diagram of a bulk control unit 106 shown in FIG.

FIG. 4 is a diagram showing an example of signal reception timing in the communication device 1 on the reception side in FIG.

FIG. 5 is a diagram for explaining the operation principle of the speed matching unit 602 shown in FIG.

FIG. 6 is a flowchart for explaining the operation of the communication device 1 shown in FIG. 1;

FIG. 7 is a flowchart illustrating a negotiation process performed in communication device 1 shown in FIG. 1;

8 is a diagram showing a flow of a test pattern for negotiation in the flow shown in FIG. 7 (in a normal state).

9 is a diagram showing a flow of a test pattern for negotiation (when a failure occurs) in the flow shown in FIG. 7;

FIG. 10 is a flowchart illustrating a bulk synchronization establishing process performed between communication apparatuses 1a and 1b illustrated in FIG. 1;

FIG. 11 is a flowchart illustrating a failure process performed in the communication device 1 illustrated in FIG. 1;

12 is a diagram illustrating an example of a change in a communication state due to a failure process in the flow illustrated in FIG. 11;

[Explanation of symbols]

 1a, 1b Communication device 2 High-speed digital dedicated line 3 Communication terminal 4a, 4b, 5a, 5b Line 101 Control unit 102 DTE interface unit 103 Communication port 104, 105 Line control unit 106 Bulk control unit 107 Control bus 108 Display unit 109 Alarm transmission Unit 601 delay time detecting unit 602 speed matching unit 603, 604 buffer

Continued on the front page (72) Inventor Takenori Chiba 94-Fuji, Koriyama-shi, Fukushima Prefecture F-term (reference) 5K028 AA11 KK01 KK03 NN22 NN23 SS24 5K030 GA01 HC04 JA01 KA03 KA21 LA15 5K034 AA01 DD01 EE07 EE13 FF03 HH01 HH02 HH12 HH17 HH21 HH37 HH42 JJ11 MM18 MM25 RR02 5K101 KK20 LL03 LL04 MM01 MM06 NN21 SS01 VV02

Claims (1)

[Claims] 1. A communication device for accommodating a plurality of digital exclusive lines and synchronizing the accommodated plurality of lines for communication, comprising: line control means for accommodating a plurality of digital exclusive lines; Means for executing a predetermined signal sequence for transmitting / receiving a test signal via the line with another communication device connected via the plurality of lines when starting up and receiving a test signal from the line. The signal sequence includes a sequence of transmitting and receiving a specific test signal via each of the plurality of lines, and the communication device further includes: a signal received via each of the plurality of lines in the signal sequence. A time difference detecting means for detecting a signal propagation time difference between the plurality of lines based on a reception timing of the specific test signal; and Synchronizing means for synchronizing signals received via each of the plurality of lines with each other in accordance with the output signal propagation time difference, and a buffer for holding a signal received via each of the plurality of lines; and According to a signal propagation time difference detected by the means, so that signals received via each of the plurality of lines are output simultaneously from the buffer, and a buffer control means for controlling the buffer, and a synchronization means comprising: Along with assembling the signals synchronized by the synchronization means in a predetermined order to form a signal and sending it to the communication terminal,
A communication device, comprising: a matching unit that divides a signal sent from the communication terminal into a plurality of signals, allocates the signals to the plurality of lines according to a predetermined standard, and transmits the signals.