JPH0514461B2 - - Google Patents

Description

[Detailed description of the invention]

[Summary] When adding call lines in exchanges that use the common line signaling system, it is possible to avoid sending and receiving unnecessary signals.
This relates to processing for transitioning to a normal call processing state after confirming a test connection. [Industrial Application Field] The present invention relates to a common line signal processing method when adding telephone lines in a digital electronic switching system that uses a common line signal method. [Prior Art] In the individual line signaling system, a control signal is included in each communication line 5 connected between stations A and B shown in FIG. 6, but in the common line signaling system, the communication line 5 contains voice , a communication line through which only data signals pass, and control signals and the like are transmitted and received using a signal line commonly provided to each communication line as a common line signal link 6. In this figure, the common line signal link 6 is shown as being installed in parallel with the speech line 5, but in reality, it usually passes through various stations. This common line signal link is a common line signal control equipment (CSE:
Common Channel Signaling Equipment）３
The CSE is controlled by a central controller (CC:
Central Controller) 1. 2
(MM) is the main memory of the central controller CC, 7, 7' is the digital switching module (DSM), 4,
4' is a trunk circuit serving as an interface.
The format of the signal transferred through the common channel signal link 6 is as shown in b, and the origin code (OPC)
14, Destination Code (DPC) 13, Circuit Identification Code (CIC) 12,
It consists of a signal type (RSC, BLO, BLA, etc.) 11 and parameters 10 depending on each signal. If the signal is from station A to station B, the source code OPC is A, the destination code DPC is B,
If it is from station B to station A, the destination code
OPC is B, and source code DPC is A. The central control unit CC and the common line signal control unit CSE are the 7th
It has the internal configuration shown in the figure. As shown in Fig. 7, the common line signal control device
The CSE includes a signal reception processing block 19 and a reception buffer 20, and the signal received from the common line signal link 6 is temporarily stored in the reception buffer 20 through the processing block and then sent to the central controller CC. The central control unit CC has a common line signal transmission/reception processing block 16 and a speech line processing block 15, and the signal from the common line signal control unit CSE is passed through the former to the latter. Common line signal control device CSE
It also includes a signal transmission processing block 17 and a transmission buffer 18, and the signal transmission processing block 17 of the common line signal control device CSE transmits according to an event passed by the communication line processing block 15 of the central control device CC to the transmission/reception processing block 16. A signal is created and sent to the common line signal link 6. [Problems to be solved by the invention] This common line signaling switching system has the following problems:
Based on CCITT's recommendations, practical implementation is planned in various countries, and some operations have begun. by the way
CCITT mainly recommends interworking for call control purposes, and does not recommend interworking for operational reasons such as changing the local station. Currently, each manufacturer handles, for example, the procedure for adding a telephone line (signal transmission/reception sequence) independently, but this does not necessarily mean that interworking is possible between switchboards from different manufacturers. If the extension procedure differs for each switching system, the following problems arise, especially when it comes to adding call lines between different switching systems. The signal reception status of the opposite station is unknown (the attributes of the call line at the other station, for example, whether the line identification code CIC is known, such as whether it is an outgoing line, whether it is about to be blocked, whether it is in an idle state, etc.) are unknown. Therefore, it is not clear when a call connection request signal for a speech line test should be sent (whether it is okay to send this signal or not). In the process of adding a call line, there is a situation where line attributes (attributes such as the signaling system, transmission form, line identification code, application information, etc. of that line) are defined for only one station. If a signal with an undefined line identification code CIC is received and ignored, the opposite station B will continue to send the same signal until it receives a confirmation signal according to the CCITT recommendation, as shown in Figure 5. The local station must receive and process this. If there are a large number of such lines (usually 100 or 200 lines are added at once), both stations A and B will repeat unnecessary transmission and reception processes many times, causing the switching system to and may affect the entire signal network. In FIG. 5, B is a station whose line identification code is defined, and A is a station whose line identification code is undefined. The signal ^* is a line reset signal (RSC) or a blockage/release request signal (BLO/UBL). Send these signals and receive a confirmation signal (RLG,
If BLA or UBA) is not returned, station B will initially retransmit the signal at intervals of 4 to 15 seconds, continue this for 1 minute, and continue to retransmit the signal at 1 minute intervals thereafter. . In the case of line expansion in the individual line signaling system, trunk attributes (line attributes such as outgoing trunk, incoming trunk, bidirectional trunk, etc.) are defined at each opposing station, and calls are made from the outgoing trunk (or bidirectional trunk) side. By starting
Tests are being conducted. The quality of the test connection usually does not affect anything other than the trunk, and the time difference in trunk attribute definitions between the two stations does not matter. However, in the common line signaling system, the above
There is a problem. This occurs during the expansion process when line attributes are defined at one station and undefined at the other station, and is a question of what kind of signal should be sent during a test when the expansion is complete. The present invention seeks to provide a means to solve these problems. [Means for solving the problem] In the present invention, the above problem is solved as shown in FIG. That is, when defining the call line attributes (CIC) of your own station, first send a line reset signal (RSC) a to the opposite station, and when the opposite station returns a reset confirmation signal (RLG) b, the next step is to issue a blockage request. Send signal (BLO) c. The signal format is as shown in Fig. 6b above. Therefore, in the first line reset signal, the destination code OPC is local station A, the source code DPC is opposite station B, the line identification code CIC is as defined above, and the signal type is 11 is a line reset signal (RSC) a. By sending the line reset signal a, station B clears the signal transmission/reception status up to that point, and by receiving the reset confirmation signal b from station B, station A can know the status of station B. By sending the blocking request signal (BLO) c, it is possible to prevent a call connection request from station B, and to send a test call connection request signal g to station B. After sending the blocking request signal (BLO) c, it waits for the blocking confirmation signal (BLA) d from the opposite station, and after this is received, a test call is entered. The above problem can be solved on the receiving side as shown in FIG. Countermeasures for this differ depending on the type of received signal, and when a line reset signal (RSC) a is received, a blocking request signal (BLO) b is sent as a confirmation signal as shown in a. reset confirmation signal). Opposing station B is now blocked and no longer sends signals to station A. When the signal from station B is a blockage request signal (BLO) or a blockage release request signal (UBL), as shown in b, after sending the confirmation signal (BLA/UBA) f, the blockage request signal (BLO) is sent. Send c.
This results in the same state as a, and the line reset signal RSC, block request signal BLO, or block release request signal UBL will not be sent repeatedly as shown in FIG. Above line reset signal RSC, blockage request signal
When a signal h other than BLO or block release request signal UBL is sent, the signal is ignored and nothing is sent, as shown in c. [Operation] In CCITT, the only signals that need to be sent repeatedly until a confirmation signal is received are the line reset signal and the blockage/release request signal, so the above process prevents the repeated reception of the same signal, and also prevents the call connection request signal from being sent repeatedly until the confirmation signal is received. It is also possible to prevent the reception of In addition, a line reset signal RSC is sent prior to the test call.
When you issue this, there is a line identification code CIC, and when this is understood, a reset confirmation signal RLG is returned from the opposite station, so by receiving the RLG, you can know the signal reception status of the opposite station and correctly enter the test call. be able to. If the opposite station cannot understand the line identification code CIC upon receiving the line reset signal RSC (CIC is undefined at the opposite station), there will be no response using the conventional method.
In addition, with the present invention, the blockage request signal BLO will be returned,
In any case, the reset confirmation signal RLG is not returned. The fact that RLG is returned means that the CIC has already been defined at the opposite station. Furthermore, as shown in Figure 1, the line reset signal
If you send and receive the blocking request signal BLO and blocking confirmation signal BLA after sending and receiving the RSC and reset confirmation signal RLG, the opposite station will not request a test call, and you can ensure that the test call is made from your own station. can be started. [Embodiment] FIG. 4 shows an embodiment in which a bidirectional trunk for CCITT No. 7 signal TUP communication line is added. Define the call line attributes as shown and send the line reset signal.
It sends RSC, receives the confirmation signal RLG, and sends a blockage request signal BLO to request line blockage.
A test call can be initiated when the blockage confirmation signal BLA is returned. Initial address (phone number) signal on test call
IAM is sent, an address completion signal ACM indicating that the telephone number has been received, and a response signal ANC are received, then a disconnection signal CLF is sent, and the test call is terminated upon receiving a recovery completion signal RLG. After that, the process moves to release the blockage, and the blockage release request signal UBL is sent, and the blockage release confirmation signal is sent.
Receive UBA. After confirming this test call and releasing the line blockage, the system enters an in-service state where normal call connections can be made. Note that these signals RSC, RLG, ... are TUP
(Telephone User Part). When using group lines, the line group reset signal GRS and maintenance line group blockage request signal MGB are used instead of RSC and BLO. For signals whose line identification code is undefined, the signals shown in the table below are returned.

【table】

〔Effect of the invention〕

As described above, according to the present invention, the line status in the opposing system is recognized when line attributes are defined, and a test call can be made reliably. In addition, even if the line identification code is undefined, a confirmation signal is sent back, so there is no need to repeat unnecessary signal transmission and reception, and even when adding a large number of call lines, there is no negative impact on the entire switching system. , etc. can be obtained.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams of the processing method of the present invention, FIGS. 3 and 4 are explanatory diagrams of the embodiment of the present invention, FIG. 5 is an explanatory diagram of the problems of the conventional method, and FIG. 7 is an explanatory diagram of the common line signaling system, and FIG. 7 is a detailed explanatory diagram of a part of FIG. 6.

Claims (1)

[Scope of Claims] 1. In a digital electronic switching system using a common line signaling method that identifies call lines by line identification codes, when adding call lines, a line including the line identification code is transmitted from the local station to the opposing station through the common line. A function that sends a reset signal a, sends a blockage request signal c when a reset confirmation signal b is returned, and enters a test call when a blockage confirmation signal d is returned, and an undefined line identification code from the opposite station. When either the line reset signal a, the blockage request signal, or the blockage release request signal e containing the line is sent,
An exchange of a common line signaling system characterized by having a function of transmitting a blockage request signal c immediately in the case of a line reset signal a, and after sending a confirmation signal in the case of a blockage request signal c or a blockage release request signal e. system.