JPH03210864A - Level 2 signal processor - Google Patents

Abstract

PURPOSE:To allow the unit to cope with a common line signal system of both of the CCITT standards and the TTC standards by converting the standard of a signal unit to be sent from a 1st standard into a 2nd standard when the designation of signal format conversion is received and converting the standard of the received signal unit from the 2nd standard into the 1st standard. CONSTITUTION:A signal conversion section 13 connects to a transmission control section 14 and a reception control section 16 and connects also to a personal computer via a control line 11 and the conversion function is set/reset by a conversion selection signal 11 from the personal computer 1 and set into the conversion state or the non-conversion state. The signal conversion section 13 converts the TTC standard of the signal unit outputted from the transmission control section 14 into the CCITT standard when the conversion function is set or converts the CCITT standard into the TTC standard inputted by the reception control section 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a level 2 signal processing device, and particularly to a level 2 signal processing device in a telephone exchange using, for example, a common line signaling system.

(Prior Art) A message transfer section of a common line signaling device of No. 7 signaling system is composed of levels 1 to 3. Level 3 performs signaling network management such as distribution of signaling messages and route selection. Level 2 is connected between level 3 and level l and performs the transmission and reception of signal units and error control. Level l is connected to the signal link and transmits and receives signal units from it.

When the transmitting side receives a predetermined control command from the level 3 signal processing device, it inserts a special link status signal unit defined in advance into the signal unit to be transmitted to the opposite device and transmits it.

The receiving side identifies the link status signal unit among the received signal units, performs a series of processing, confirms the normality of the signal link, and then notifies the processing device of level 3 or higher that it is operational.

After notification that operation is possible, error retransmission control, congestion control, etc. are performed in response to transmission requests from processing devices of level 3 or higher, and error-free signal units are matched by the signal unit order reversal prevention and loss prevention functions. Send to device. If the signaling device becomes impaired, the loss of the signaling unit will occur. In this case, the level 2 signal processing device initializes the opposing device. For example, Japanese Patent Laid-Open No. 63-22741 discloses a prior art related to this initialization.

The current common line signaling system is being standardized internationally through CCITT recommendations, and domestically through TTC standards. On the other hand, in the domestic market, the common line signaling system based on the CCITT standard is currently mainly used.

(Problem to be Solved by the Invention) Therefore, for example, when connecting a TTC standard telephone exchange to an existing network forming a common line signal network based on the CCITT standard, it is necessary to There was a problem that connection could not be established because the field configurations of the departure/arrival signal station code and line number were different. In addition, in order to solve this problem, for example, adding CCITT standard processing functions to a level 3 or higher processing unit that performs signal processing will complicate the software structure of the signal processing device and reduce the processing capacity of the main device itself. There was a problem with letting it happen.

The present invention eliminates the drawbacks of the prior art and provides a level 2 signal processing device that allows the exchange to support common channel signaling systems of either the CCITT standard or the TTC standard without being limited to the standard of the exchange. The purpose is to

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a level 2 signal processing device for the NO, 7 common line signaling system in a telephone switching network, which controls transmission control for controlling transmission of transmission signal units. means and
It has a reception control means for correcting errors in the received signal unit, and a signal conversion means connected to the transmission control means and the transmission and reception control means, and when the signal conversion means receives a designation to convert the signal format, The signal standard of the transmission signal unit sent from the transmission control means is converted from the first signal standard to the second signal standard, and the signal standard of the signal unit received by the reception control means is converted from the second signal standard to the first signal standard. Convert to signal standard.

(Function) According to the present invention, when the signal conversion means receives an instruction to convert the signal format, the signal conversion means changes the standard of the signal unit transmitted from the transmission control means from the first standard to the first standard. The standard of the signal unit received by the receiving means is converted from the second standard to the first standard.

(Example) Next, an example of a level 2 signal processing device according to the present invention will be described in detail with reference to the accompanying drawings.

The level 2 signal processing device of this embodiment is connected to a communication network using a common line signaling system of the CCITT or TTC standards, and processes changes between the two standards using, for example, hardware. FIG. 2 shows a telephone exchange system to which this embodiment is applied, and is composed of a telephone exchange 2 and a common line signaling device 10. Note that in the common line signal device IO in the same figure, constituent elements not directly related to the present invention are omitted for ease of understanding.

The telephone exchange 2 is an exchange designed according to the TTC standard signal format. The telephone exchange 2 is also capable of connection processing to networks forming a common line signaling network based on the CCITT standard signal format by means of the common line signaling device IO.

The level 3 processing unit 4 of the common channel signal processing unit 1 performs network management such as distribution of signal messages to level 4 signal processing units (not shown) and route selection.

The level 2 signal processing device 5 controls the transmission and reception of the signal unit, performs error correction on the received signal unit, and converts the TTC standard signal of the telephone exchange 2 to the CCITT as necessary.
Convert it to conform to the standard communication network.

The presence or absence of standard conversion is set by a conversion selection signal 11 output from the personal computer 1 through the man-machine interface 3. The level I processing unit 7 is connected to the signal link 9 and performs conversion processing between the signal of the link and the logic level signal in the level 2 signal processing device 5. Note that if the standards of the telephone exchange 2 and the communication network are the same, no conversion settings are made for the level 2 signal processing device 5.
The level 2 signal processing device 5 controls transmission and reception of signal units and corrects errors in received signal units, but does not perform signal conversion processing.

FIG. 3 shows the basic signal format of the TTC standard and CCITT standard. The differences between these standards will be explained using the figure. In the signal format of the TTC standard, the communication line number (CIC), the originating station number topc), and the receiving station number IDPc) of the routing label preceding the message tM) are each composed of 16 bits. On the other hand, in the CCITT standard, the communication line number (CICI) of the routing label is 12 bits, and the originating station number (O
The level 2 signal processing device 5 in this embodiment has both the conventional level 2 processing and the TTC/CCI processing.
Performs TT standard conversion.

FIG. 1 shows a functional block diagram of an embodiment of a level 2 signal processing device according to the present invention. In the signal processing device 5, the transmission control section 14 is connected to the level 3 processing section 4 via the reception tIIA 20, and receives the transmission message from this. The transmission control unit 14 constructs a signal unit from the received transmission message. The transmission control unit 14
A forward direction number is assigned to the configured signal unit, the signal unit is stored in a retransmission buffer (not shown), and the signal unit is sent to the transmission/reception control section 18. The transmission control section 14 also retransmits the signal units accumulated in the buffer when receiving a retransmission request from the congestion control section 15.

The transmission/reception control section 18 is connected to the level I processing section 7 via a transmission line 24o and a reception line 26. The transmission/reception control section 18 outputs the transmission signal unit from the transmission control section 14 through the transmission line 24 and sends the reception signal unit input from the reception line 26 to the reception control section 16 .

The reception control unit 16 checks the backward order of the received signal units, and if it is correct, sends it to the level 3 processing unit 4.
If there is an error, it is output to the congestion control unit 15 that requests retransmission. The congestion control unit 15 that has received the error detection estimates the traffic amount of the signal link by outputting a retransmission request to the transmission control unit 14.

The link state control section 12 is connected to the transmission control section 14 and the reception control section 16. The link state control unit 12
When the frequency of reception errors exceeds a predetermined value, a message is sent to the transmission control unit 14 to initialize the opposing device (not shown).

The signal conversion section 13 includes a transmission control section 14 and an amount control section 16.
is connected to the personal computer via the control m1ll.
(Fig. 2) is also connected. The conversion function of the signal conversion unit 13 is turned on/off by a conversion selection signal 11 from the personal computer 1, and is thereby set to a conversion state or a non-conversion state. In the conversion state where the conversion function is on, the signal conversion unit 13 converts the TT of the signal unit output by the transmission control unit 14.
C standard to CCITT standard, and reception control unit 16
Converts the input CCITT standard to the TTC standard.

Note that in this example, since the exchange is based on the TTC standard, the CC
Although a case has been shown in which the communication network conforms to the ITT standard, the present invention is not limited to this. In other words, even if the switching equipment is set to the CCITT standard and the communication network is set to the TTC standard, the signal converter 13 is By adapting to this,
Similarly, signal standard conversion processing can be performed. In this case as well, the designation of whether or not conversion processing is to be performed is set in the signal conversion unit 13 from the personal computer. Therefore, the level 2 signal processing device 5 can also be used in systems that do not require conversion, and can also be used for different signal standards without having to replace the system when conversion processing becomes necessary. It becomes possible.

(Effects of the Invention) According to the present invention, the software processing of the upper level device of level 3 or above is hardly changed (, TT
C standard signal to CCITT standard signal,
It becomes possible to convert T-standard signals into TTC-standard signals. Therefore, a common line signaling device having this device is not limited to the original standard, and can be connected to a communication network of any standard without reducing its processing capacity.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing an embodiment of a level 2 signal processing device according to the present invention, FIG. 2 is a configuration diagram of a telephone switching system to which the present invention is applied, and FIG. 3 shows differences in routing labels. It is an explanatory diagram. Major. τshi is 191. Personal computer 2゜Telephone exchange Level 3 processing unit Level 2 signal processing device Level l processing unit Common line signaling device Link status control unit Signal conversion unit Transmission control unit Congestion control unit Reception control unit Transmission/reception control unit

Claims (1)

[Claims] 1. No. 1 in the telephone switching network. 7 common channel signaling level 2 signal processing device, the device comprises: a transmission control means for controlling transmission of a transmission signal unit; a reception control means for correcting errors in a reception signal unit; and the transmission control means and the transmission/reception unit. and a signal conversion means connected to the control means, and upon receiving an instruction to convert the signal format, the signal conversion means converts the signal standard of the transmission signal unit sent from the transmission control means into a first signal format. A level 2 signal processing device, characterized in that it converts a signal standard to a second signal standard, and converts the signal standard of a signal unit received by the reception control means from the second signal standard to the first signal standard. . 2. In the level 2 signal processing device according to claim 1,
The level 2 signal processing device is characterized in that the signal conversion means is configured to externally determine whether signal format conversion is necessary or not.