JPS6013349B2 - Dedicated line reconfiguration method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reconfiguring a dedicated line in the event of a trunk line failure in a switched network that accommodates the dedicated line via an exchange switch.

A part of the transmission path in the communication network is used as a dedicated line,
When connecting these transmission lines to a space-division type or time-division type exchange, the dedicated line was bypassed by the dedicated line, and only the general connection line was accommodated in the exchange.

However, with this accommodation method, it is necessary to provide branching/insertion functions and multiplexing/demultiplexing functions outside the exchange, and when increasing/decreasing the capacity of the dedicated line or replacing the capacity, it is necessary to change the equipment with the above-mentioned functions. It was necessary to change the wiring of jumpers on the wiring rack, which caused problems in terms of economy and maintainability. Therefore, the transmission line (for example, a time division multiplex transmission line), which is partially used as a dedicated line, is connected to the exchange, including the dedicated line, and the dedicated line is fixedly connected via the communication line system. An accommodation method has been proposed that eliminates the need for special equipment for this purpose and allows for easy expansion and replacement of dedicated lines.

By the way, in a switched network that accommodates dedicated lines via such exchange switches, if a relay line becomes faulty, there are two methods: wait for the faulty relay line to recover without taking any measures, or wait until the relay line is restored. Methods such as notifying the line failure status to the maintenance personnel and allowing the maintenance personnel to set up a new route are adopted. With these methods, the dedicated line becomes disconnected due to a failure in the trunk line, leading to a decline in transmission quality.In addition, because the line is manually reconfigured, the dedicated line is interrupted for a long time. The burden is heavy.
In a switching network that accommodates a dedicated line via an exchange switch, the present invention provides a method for automatically reconfiguring the dedicated line using another line in the event of a failure in the trunk line, and detecting the failure. The purpose of this is to avoid affecting the upstream stages of the station.

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

FIG. 1 is a block diagram of a dedicated line resetting method.

Now, when setting up a dedicated line between certain terminal devices using part of the time division multiplex transmission path, each time division switch DS
In E, the retention memory and time of the Highway Q gate can be maintained using maintenance personnel's commands, etc., without setting and releasing communication channels for each call.

Control information regarding the dedicated line is fixedly set by writing data to the slot phase conversion holding memory. FIG. 2 is a channel allocation diagram in a time division multiplex transmission path.

From the concentrator to the switch DSE and the switch DSE
The trunk lines between each other are time division multiplexed (for example, C
CITT Recommendation X50), which is shared by multiple calls.

That is, data from a certain terminal is divided into 6 bits as shown in Figure 2, and a framing bit F and a status bit S are added to the 6 bits of data, and the data is divided into 8 bits as a unit. Multiplexed.
Time slots A for leased line calls from terminals are arranged in a time-sharing manner as shown in the figure.

Further, the value of the status bit S matches the value of the control line from the terminal on the interface between the terminal device and the line termination device. FIG. 3 is a block diagram of the time division switch in FIG. 1.

A trunk line fault detection device FD is provided for each line, and the control line from the detection device FD and the control line from the exchange switch NW are connected to the interface device INTF (communication system control device and central processing unit). It is coupled to the central processing unit CPU via a signal transmitting/receiving device).

A storage device MEM is connected to the central processing unit CP Yamako for storing the subscriber's provided service class (general connection service or dedicated line service) and dedicated line path information along with other control information. .

Now, when a failure occurs in the trunk line, the trunk line failure detection device FD detects this and notifies the processing device CPU via the interface device INTF.

As explained in FIG. 2, the line connection FL is shared by a plurality of calls in a time-sharing manner, and calls for the general connection service and calls for the dedicated line service are combined and connected. The processing unit CPU identifies whether the connection using the failed trunk line is a general connection service or a dedicated line service by reading the subscriber service class information stored in the storage device MEM, and determines whether the connection using the faulty trunk line is a general connection service or a dedicated line service. If it is a service, "Restore the channel of this trunk line.

On the other hand, in the case of a dedicated line service, the process immediately moves to a resetting request without restoring the connection on the subscriber side. That is, in the present invention, ``the station that detects the failure performs processing for requesting leased line re-arrangement, and immediately selects a detour route from this station without the failure affecting the previous stage.
The processing unit CPU reads the path information of the dedicated line stored in the storage unit MEM, and sends out a resetting request signal using an empty channel of another trunk line. For example, in FIG. 1, the switching center DSE-1 that has detected a fault, before the fault occurs,
The data on the dedicated line assigned to
If it is sent to E-2, the highway gate holding memory and time
The contents of the slot phase conversion holding memory are automatically rewritten, and the data of the dedicated line assigned to the time slot t of the incoming highway is transferred to the time slot t3 of the outgoing highway of the 8U route via the communication path section. Adjacent station D
Send to SE-3. In that case, the fault detection station DSE-1
sends out a general dialing signal as if the call was made from the subscriber terminal, and also notifies that it is a dedicated line setup request. Similarly, in the adjacent station DSE-3, by setting the control information regarding this dedicated line in a fixed manner, the data of the dedicated line assigned to the time slot W on the incoming highway can be transferred to the time slot W on the incoming highway. time.

It is sent to the adjacent station DSE-2 in slot L. Station DSE-
In step 2, based on the path information of the dedicated line stored in the storage device MEM, "select the same trunk line as before the failure" and the same channel, and send the data on the dedicated line to the subsequent stage, and from then on, connect the same route as before the failure. It is connected to the subscriber terminal via the fault trunk line FL.
However, in reality, in many cases, the station that returns from the detour route to the pre-failure route is further away.

In Fig. 1, the station that detects the fault is the station DSE.
Since not only station DSE-1 but also station DSE-2 can be detected, if the dedicated line is reset at both stations, it will cause a malfunction.

Therefore, between two exchanges that accommodate trunk lines, a distinction is made between priority and non-priority for each leased line.When a trunk line fails, only one of the exchanges, that is, the priority station, can use the leased line. For example, in Figure 1, in a certain dedicated line, station DSE-tortoise is prioritized, station DSE-tortoise is prioritized, and station DSE-
2 as non-priority and store the information in each storage device M old M, when a faulty trunk line FL is detected,
Only the station DSE-1 can reconfigure the dedicated line by proposing and collating the priority and non-priority information in the storage device MEM. In this case, the station DSE-2 can be given priority for another dedicated line that uses the failed trunk line FL. Although the present embodiment has been explained using a time-division switching system as an example, the present invention can also be applied to a space-division switching system such as a conventional telephone switching network.

As explained above, according to the present invention, when a fault occurs in a trunk line, among the stations that have detected this, the station that has priority for the dedicated line that uses that trunk line Since the dedicated line is automatically reconfigured using You can reset the settings.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a leased line reconfiguration system showing an embodiment of the present invention, FIG. 2 is a channel allocation diagram of the time division multiplex transmission line in FIG. 1, and FIG. 3 is a diagram of the switching center in FIG. 1. It is a block diagram. FD; Trunk line failure detection device, DSE-1, DSE-2:
Switching station that can detect failures, DSE-3: Detour relay station, C
PU: Central processing unit, FL: Faulty trunk line, M old M storage device, NW: Replacement switch, TF: Interface device, F: Framing bit, S: Status bit, A: Assigned to a certain dedicated line time slot. Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. In a communication switching network that provides a dedicated line service by using a part of the transmission path in the communication network as a dedicated line and fixedly connecting subscribers to each other via an exchange switch, The switch is equipped with a function to detect a trunk line fault and a function to identify whether the connection using the trunk line is a general connection service or a dedicated line service, and when the switch detects a trunk line fault, the trunk line is used. A dedicated line reconfiguration method characterized in that for a dedicated line among connections that have been made, another trunk line is automatically selected from the exchange to reconfigure the dedicated line connection. 2 For the two exchanges that accommodate the trunk lines used to connect the leased lines, a distinction is made between priority and non-priority for each leased line, and when the exchange detects a failure in the trunk line, the priority leased line 2. The dedicated line reconfiguration method according to claim 1, wherein the dedicated line connection is reconfigured from the exchange only for the private line.