JPH05252231A - Station address decision method - Google Patents

Abstract

PURPOSE:To improve the utilizing efficiency of a center side installation and to reduce the installation cost by sending a command from a destination equipment whose address is set and allowing a receiver side communication controller to decide its own station and the other station address based on the address used for the setting. CONSTITUTION:Received bit serial information is extracted as a frame by a line control section 11, and when an error check code is checked and it is correct, it is informed to a station address decision control section 14. Sets of two addresses used for its own station and other station are stored and when a value of an address section of a reception frame is coincident with any address, whether the reception frame is a command or a response based on the reception frame control value is discriminated. In the case of the former, it is used for its own station address and the other address decided in advance is set to a transmission control section 12 as a destination station address. Furthermore, in the case of the latter, it is used for the destination station address and the other is used for its own station address and the result is sent to the control section 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control device for performing data communication with a partner device via a communication line according to a high level data link control procedure (HDLC).

[0002]

2. Description of the Related Art CCITT (International Telegraph and Telephone Advisory Committee)
Recommendation X. 32, X. In the control procedure called LAPB of Layer 2 of 25, the high level data link control procedure such as ISO (International Organization for Standardization) 7776, the frame is composed of a flag sequence, an address section, a control section, an information section, a frame check sequence and a flag sequence. Command and response. At the time of frame transmission, as the value of the address section of the frame, the station address of the partner is set by the command, and the address of the own station is set by the response.

Therefore, if the value of the address part of the frame received by the communication control device is the address of the own station, it is a command, and if it is the address of the other station, it is a response.
The communication control device discriminates the command and response from the address value of the received frame, and then discriminates various commands and responses from the value of the control unit. FIG. 5 shows frame configurations and frame types related to the data link setting phase.

There are the following two methods for determining the station address. One is a method of arranging the address between the local station and the other station in advance when using a switched line or a dedicated line (hereinafter called fixed method), and the other is only when a switched line is used. The method of arranging the value of the station address depending on whether the calling side or the called side (hereinafter referred to as a floating method). CCITT Recommendation X. Reference numeral 32 is a protocol between the DTE and the DCE for accessing the packet switching network via the switching network, and a fixed system and a floating system are provided for determining the station address of the data link layer. As the circuit switching network, ISDN (Integrated Services Digital Network) circuits, circuit switching data networks, and telephone switching networks are targeted.

In ISO, two DTEs via a switched line are used.
In between. There is a protocol for connection-oriented network services using the 25-packet procedure, and a fixed method and a floating method are provided for determining the station address of the data link layer. The following three types of switching lines are targeted. The standard numbers are ISO9574 for the B channel of the ISDN line, DIS10588 for the line switching data network, and DI for the telephone switching network.
S (Draft International Stan
10732.

X. In 25, the station address is fixed. In the above-mentioned CCITT recommendation, ISO standard, 03 and 01 are used as the standard value of the station address, and in the floating system, the sender side is 03 and the sender side is 01. The X. In 25 layer 2, DCE (network side) is 01, DT
E (terminal side) uses the station address of 03. Further, in the fixed method, a plurality of groups of two address values are prepared and one group can be selected and used.

In the above-mentioned conventional technique, the method of determining the station address has to be set in advance for each line accommodation port of the communication control device, so that there is the following problem.

[0008] In the exchange line, in consideration of the connection frequency of terminal users, a representative telephone number is provided for two methods of determining a station address, a fixed method and a floating method, and a plurality of line accommodation ports are prepared. For this reason, even if all lines that support a certain method are in use and there is a vacancy in the line that supports another method, a terminal busy situation occurs for terminal users who want to use another method. As a result, serviceability and equipment use efficiency deteriorate. Also, since the terminal user has different line accommodation ports depending on the method of deciding the station address to use, the terminal user selects a telephone number corresponding to the method of deciding the station address of his / her terminal and calls the center side. There must be.

Although the address determination system for the leased line is a fixed system, every time a new terminal is accommodated or whenever the terminal is changed, it is investigated / confirmed whether 03/01 or other address information is used. Then, it is necessary to set / change the address values of the corresponding own station and the partner station, or accommodate the line to the line accommodation port having the same value.

The above points will be described in more detail with reference to FIG. FIG. 6 shows the internal configuration of the communication control device.

In FIG. 6, the communication control unit 1 is a DSU.
The communication line 2 is accommodated via the (terminal) 3. In the components of the communication control device 1, 11 is a line control unit, 12 is a transmission control unit, and 13 is an upper interface unit. The line control unit 11 performs electrical matching between the DSU 3 and the communication control unit 1, frame assembly / disassembly, addition / check of error check code, and monitoring / control of DSU signal line. The transmission control unit 12 executes LAPB procedure processing. Also, A and B are symbols indicating line termination ports. The station address determination method is preset and fixed for each line accommodation port.

Now, it is assumed that the station address determination method for the line accommodating port A is a fixed method, and that the own station = 03 and the partner station = 01. The operation when the station address determination method of the partner device connected to the main line is the fixed method is as follows.

When attempting to start communication, the partner device sends a data link establishment command (SABM) in which station address = 03 is set. The bit serial information received from the line is extracted as a frame by the line control unit 11, and if the error detection code is checked correctly, the line control unit 11 transmits this frame (SABM) to the transmission control unit 12.
Notify to.

The transmission control unit 12 checks the station address of the received frame and determines that it is a command because the same '03' as the address value of its own station is set. Then, it is determined from the control value of the frame that this frame is a SABM command, and the line control unit 11 is requested to transmit a UA response that is an affirmative response. This establishes the data link,
Data transfer can be performed.

[0015]

However, when the station address determination method of the partner device connected to the line accommodating port A is a floating system and the partner device originates the call and receives the call at the communication control device 1, It becomes like this and the data link cannot be set. That is, since the partner device is the originating side, the partner device sends the SABM command with 01 set in the address part. The line control unit 11 extracts the frame and notifies the transmission control unit 12 if the error detection code is correct. The transmission control unit 12 checks the station address of the received frame, and determines that it is a response because the same value “01” as the partner station address value held by the transmission control unit 12 is set. However, since there is no corresponding response from the control unit value of the frame, this frame is discarded. Therefore, the data link cannot be established and communication cannot be performed.

Therefore, in view of the above points, an object of the present invention is to irrespective of the station address setting method of the partner station, based on the reception information from the partner station whose address is determined when the data link is established. Another object of the present invention is to provide a station address determination method capable of identifying its own station address and internally setting it in the communication control device.

[0017]

In order to achieve such an object, the invention according to claim 1 is the second communication control device side connected to the first communication control device by a communication line. The own station address for the second communication control device and the other station address for the first communication control device are determined, and using the determined own station address and other station address,
In the station address determination method for transmitting a command and a response from the second communication control device to the first communication control device, one of the address values is used as the own station address and the other is used. Two address values used as the other station address are held in advance in the second communication control device, and when the communication line is connected, one of the two address values from the first communication control device is held. A frame including one address value and a control value indicating that this transmission information is a command is transmitted to the second communication control device, and the second communication control device transmits the two frames in the received frame. If a determination process of whether or not the same address value as any of the address values and the control value is included is performed and a positive determination is obtained as the determination result, In addition, the second communication control device determines an address value included in the received frame as the own station address, and determines the other address value of the determined address value of the two addresses. It is characterized in that it is determined as the other station address.

According to a second aspect of the present invention, in addition to the first aspect of the invention, the determination is made when the second communication control device holds a plurality of sets of address values with the two address values as one set. The processing determination condition is that any one of the plurality of sets is included in the received frame and the control value is included.

According to a third aspect of the present invention, the second communication control device is connected to the first communication control device by a communication line.
Own station address for the communication control device of the
Other station address for the communication control device of the above, and using the determined own station address and other station address, command and response from the second communication control device to the first communication control device In the method of determining a station address for transmitting a message, any one of the two address values is used as the temporary other station address from the second communication control device when the communication line is connected. When a command is transmitted to the first communication control device, the presence or absence of a response from the first communication control device is determined in the second communication control device, and the result of the determination is affirmative, , After confirming that the address value used for the response is one of the two address values held in advance, the address value used for the response is set to the maximum value. And the other address value of the two address values used for the response is determined as the final address of the own station, and the result of the determination is negative. When the determination is made, the temporary other station address is switched to an address value other than the currently used address value of the two address values, and a command is issued from the second communication control device. It is characterized in that it is transmitted to the first communication control device, and a determination process regarding the presence or absence of the response and a determination process regarding the final other station address and its own station address are executed.

According to a fourth aspect of the present invention, in addition to the third aspect of the invention, in the case where the second communication control device holds a plurality of sets of address values with the two address values as one set, the response Until the presence determination is obtained, the set of address values used for the command is sequentially switched, and the switched command is transmitted from the second communication control device to the first communication control device. To do.

[0021]

According to the present invention, it is possible to send a command and a response from the communication control device to the partner device regardless of the fixed system or the floating system if the own station address and the other station address are known. In the invention of claim 1, a command is transmitted from the partner device (first communication control device) whose address is determined, and the communication control device on the receiving side (second communication) is transmitted from the address used for the command. Control device)
Determines its own address and other station address.

According to the second aspect of the invention, a plurality of address values of the own station and the other station that are held in advance are used so that they are used with the plurality of first communication control devices connected to the second terminal device. The address can be determined.

According to the third aspect of the invention, the second communication control device side sequentially switches the address of the other party to transmit a command, and when there is a response to this command, it is used for the response. Second from address
Determines the own station address and the other station address used in the communication control device.

Also in the fourth aspect of the present invention, the address values of the own station and the other stations that are held in advance are set to a plurality of values, so that the second
It is possible to determine the address to be used with the plurality of first communication control devices connected to the terminal device of the.

[0025]

Embodiments of the present invention will now be described in detail with reference to the drawings.

Prior to the description of the present invention, a communication control device to which the present invention is applied will be described with reference to FIG. The same parts as those in the conventional example of FIG. 6 are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 2, the communication control unit 1 has a DSU 3
The communication line 2 is accommodated via. In the configuration of the communication control device 1, 11 is a rotation control unit, 12 is a transmission control unit, 13
Is a high-order interface unit, and 14 is a station address determination control unit using, for example, a central processing unit (CPU).

The line control unit 11 performs electrical matching between the DSU 3 and the communication control unit 1, frame assembly / disassembly, addition / checking of error check code, and monitoring / control of the DSU signal line. The transmission control unit 12 executes LAPB procedure processing. The host interface unit 13 exchanges information with the host device. Further, A and B are symbols indicating line accommodation ports.

The bit serial information received from the line is
The line control unit 11 extracts the frame, checks the error detection code, and if it is correct, the rotation control unit 11 notifies the station address determination control unit 14 of this frame. The station address determination control unit 14 holds a set of two address values in which one of the address values is used as an address for its own station and the other is used as an address for another station, and the value of the address part of the received frame is Check if it matches any of these values. When the value of the address part of the received frame matches any one of the two predetermined address values, it is determined from the control part value of the received frame whether the received frame is a command or a response. If the received frame is a command, the value of the address portion of the received frame is set as the own station address, and the other predetermined address value is set as the partner station address in the transmission control unit 12. If the received frame is a response, the value of the address part of the frame is set as the partner station address, and the other predetermined address value is set as the own station address in the transmission controller 12.

When the value of the address part of the received frame does not match any of the predetermined address values, the frame is discarded. In the prior art, after distinguishing the command and response from the address value of the received frame, various commands and responses were identified by the value of the control unit. In this embodiment, the frame to be identified is related to the data link setting phase. By limiting to the frame type of (1), the command and the response are identified from the control unit value of the frame (control value of the present invention, see the communication format of FIG. 5). The station address setting method when using a set of address values (03, 01) will be described below.

A partner station whose address has been determined (claim 1
Command information is received from the first communication control device of the invention of claim 1, and the communication control device (the second communication control device of the invention of claim 1) 1 determines its own station address and other station address from the received content. Will be described with reference to FIGS.

FIG. 1 shows the operation contents of the station address determination control unit 14 shown in FIG. FIG. 3 shows a specific detailed procedure of the station address determination control unit 14 for determining the station address.

When the partner device is the originating side and the partner device connected to the line accommodating port A has a floating address determination method, the communication control device 1 operates as follows. On the partner device side, since the own station address is previously determined to be 03, the SABM in which the destination station address = 01 is set
(Set Asynchronous Balance
d Mode) command.

The line controller 11 of the communication control device 1 extracts this frame (SABM) from the bit serial information received from the partner device via the line, checks the error detection code, and if correct, determines the station address. Notify the control unit 14. The station address determination control unit 14 confirms that the value 01 of the address portion of the received frame matches any one of the address information values (03, 01) held in advance and held (step P1 in FIG. 3). Or P2), and from the value of the control part of the received frame, this frame is S
It is determined that the command is an ABM command (step P10 in FIG. 3).

Therefore, the own station address of the line of the communication control device 1 is the value 01 of the address part in the received frame.
Then, the partner station address is set in the transmission control unit 12 as the other value 03 (step S0 → S10 in FIG. 1, step P11 in FIG. 3). Then, the transmission control unit 13
The BM command is notified and the data link establishment process is instructed. The transmission control unit 13 is an ACK (Unnumbered Ackno) which is an affirmative response in which the station address = 01 is set.
Instruct the line control unit 11 to transmit a wledgement response (steps S11 → S12 in FIG. 1, FIG. 3).
Step P12 → P13). As a result, a data link is established and data transfer can be performed.

If the station address determination method of the partner apparatus is fixed and the station address of the partner apparatus = 01, the operation is as follows. The partner device transmits the SABM command in which the station address = 03 is set. Line control unit 11
Extracts the frame (SABM) from the bit serial information received from the line, checks the error detection code, and if it is correct, notifies the station address determination control unit 14. The station address determination control unit 14 determines the value 03 of the address portion of the received frame and the held address information value (03,0
It is confirmed that one of 1) matches (step P1 or P2 in FIG. 3), and it is determined from the control value of the received frame that this frame is a SABM command (step P10 in FIG. 3). ..

Therefore, the own station address of the line of the communication control device is set to the value 03 of the address part of the frame and the other station address is set to the other value 01, and the transmission control part 12
(Step S0 → S21 in FIG. 1). And
The transmission control unit 12 is notified of the SABM command and is instructed to perform the data link establishment process. The transmission control unit 12 instructs the line control unit 11 to transmit a UA response which is a positive response. As a result, a data link is established and data transfer can be performed.

Communication controller 1 whose address is undecided
Is a transmitting side (command information transmitting side-second communication control device of claim 3), and a partner device whose address is determined (first communication control device of claim 3) is a receiving side. 1, it demonstrates using FIG. FIG. 4 shows a specific detailed procedure of the station address determination control unit 14 for determining the station address.

In this case, the station address determination control unit 14 of the own station transmits the SABM command with the address value 03 or 01 as the partner station address, but the station address determination control unit 14 first The other party's address part is set to 03
The line control unit 11 transmits the temporarily set SABM command.
And activates a timer to monitor the reception of the UA response, which is a positive response (step S3 in FIG. 1).
0 → S31, steps P50 to P52 in FIG. 4).

When the received frame from the partner device is the UA response with the station address = 03, it is processed as follows. That is, when the station address determination control unit 14 confirms the reception of the frame before the timer times out (steps P53 → P54 in FIG. 4), the value 03 of the address part of the received frame and the held address information value ( 03,0
It is confirmed that any one of 1) matches, and further it is judged from the control unit value of this frame that it is a UA response (steps P55 → P56 in FIG. 4). The initial temporary address of the own station 01 and the temporary address of the opposite station 0
The value of 3 is set in the transmission control unit 12 as the final setting address, the transmission control unit 12 is notified that the data link is established, and the timer is stopped (step S in FIG. 1).
40 → S41 → S42 → S43, P55 to P5 in FIG.
7).

Further, when the received frame is a FRMR (Frame Reject) response with the station address = 01, it is processed as follows. That is, the station address determination control unit 14 confirms that the value 01 of the address part of the received frame and the held address information value (03, 01) match, and further, the FRMR is determined from the value of the control part of this frame. It is determined that it is a response (steps P55 → P60 in FIG. 4). Therefore, the station address is replaced with the own station address 03 and the partner station address 01 (steps P60 → P61 in FIG. 4) to instruct the line control unit 11 to transmit the SABM command in which the address part is set to 01, and with an affirmative response. A timer is activated to monitor the reception of a certain UA response (step P61 → P5 in FIG. 4).
1, steps S61 to S64 in FIG. 1).

Since the partner station sends back a UA response by transmitting the SABM command with the addresses exchanged, the execution procedure of the station address determination control section 14 shifts to the procedure of steps P53 to P57 in FIG. After confirmation, the final addresses of the own station and other stations are determined from the reception address when the UA response is received.

If the frame is not received within a certain period of time after the SABM command of the temporarily set address is transmitted and the frame times out (step P53 in FIG. 4), the address values of the own station and the partner station are exchanged, that is, the partner station address. = 01, the line control unit 11 is instructed to transmit the SABM command, and the timer is activated to monitor the reception of the UA response, which is an affirmative response (step P70 → P in FIG. 4).
51 → P53).

Hereafter, the final address determination is performed by receiving the UA response, as in the above case.

<Other Embodiments> A plurality of sets of two address values are prepared as in the case where one communication control device is connected to a plurality of communication control devices, and one set is used for station address determination control. When selecting and using the unit 14 (corresponding to the invention of claim 2), the station address determination control unit 14
Holds a plurality of sets of address information. Then, in contrast to the processing when one set of addresses is used in the above-described embodiment, it is necessary to search a plurality of sets of address information for a set of addresses that match the address value of the received frame. More specifically, the process of P1 and P2 in FIG. 3 is a process of determining whether the address of the received frame is included in any of a plurality of sets of address values.

When the communication control device is on the transmission side (corresponding to the invention of claim 4), a plurality of sets held by the station address determination control unit 14 are held until the address is determined by the address value of the received frame. SAB is sequentially obtained from the address information until the UA response is obtained.
The address of the M command is switched and set, and the command is transmitted.

[0047]

As described above, according to the present invention,
If the station address of one communication control device has been determined,
Since it is not necessary to preset the station address of the other communication control device corresponding to the line accommodating port, it is not necessary for the user to manually set the station address. Therefore, the communication control device, D
The center side equipment such as SU and the number of lines can be efficiently used, the equipment cost can be reduced, and the system design can be facilitated, so that the design cost can be reduced. If the line to be used is a switched line, only one representative number telephone number on the center side is provided, and the user of the terminal need only know this number, which is convenient. Further, in the case of a dedicated line, even if the station address is changed by changing the terminal, it is not necessary to change the equipment on the center side, so maintenance and operation costs can be reduced.

[Brief description of drawings]

FIG. 1 is a station address determination control unit 1 according to an embodiment of the present invention.
4 is a flowchart showing the processing contents for each type of reception information of No. 4 of FIG.

FIG. 2 is a block diagram showing a circuit configuration of an embodiment of the present invention.

FIG. 3 is a flowchart showing a processing procedure of a station address determination control unit 14 of FIG. 2 for determining a station address by a reception command.

4 is a flowchart showing a processing procedure of a station address determination control unit 14 of FIG. 2 for determining a station address based on a received response.

FIG. 5 is an explanatory diagram showing a configuration of a communication frame.

FIG. 6 is a block diagram showing a circuit configuration of a conventional example.

[Explanation of reference numerals] 1 communication control device 2 communication line 3 DSU 11 line control unit 12 transmission control unit 13 upper interface unit 14 station address determination control unit A, B line accommodating port identifier

Claims (4)

[Claims] 1. A second communication control device, which is connected to the first communication control device by a communication line, has its own station address for the second communication control device and other information for the first communication control device. A station for determining a station address and transmitting a command and a response from the second communication control apparatus to the first communication control apparatus using the determined own station address and other station address In the address determination method, two address values, one of which is used as the own station address and the other of which is used as the other station address, are stored in advance in the second communication control device, and the communication is performed. At the time of line connection, one of the two address values and a control value indicating that the current transmission information is a command are transmitted from the first communication control device. Send a no-frame to the second communication control device, the second communication control device includes a same address value as any of the two address values in the received frame,
When the determination process of whether or not the control value is included is performed and a positive determination is obtained as a result of the determination, the second communication control device determines that the address value included in the received frame. Is determined as the own station address, and the other address value from the determined address value of the two addresses is determined as the other station address. 2. When the second communication control device holds a plurality of sets of address values with one set of the two address values, the determination condition of the determination process is set to the plurality of sets in the received frame. The station address determination method according to claim 1, wherein any one of the above is included and the control value is included. 3. A second communication control device side connected to the first communication control device by a communication line, and a local address of the second communication control device and other information about the first communication control device. A station for determining a station address and transmitting a command and a response from the second communication control apparatus to the first communication control apparatus using the determined own station address and other station address In the address determination method, when the communication line is connected, the second communication control device
A command that uses any one of the two address values as the temporary other station address is transmitted to the first communication control device, and whether or not there is a response from the first communication control device is determined by the first communication control device. The communication control device of No. 2 makes a judgment, and when the result of the judgment is a positive judgment, it is confirmed that the address value used for the response is one of the two address values held in advance. Then, the address value used for the response is determined as the final address of the other station, and the address value of the other of the two address values used for the response is the final address of the own station. When the result of the determination is negative, the temporary other station address is set as the currently used address value of the two address values. The command is switched to the other address value and the command is transmitted from the second communication control device to the first communication control device, and the determination process regarding the presence or absence of the response and the final other station address and the own station address are performed. A station address determination method characterized by executing a determination process. 4. When the second communication control device holds a plurality of sets of address values with the two address values as one set, an address used for the command until the determination that there is a response is obtained. 4. The station address determination method according to claim 3, wherein the set of values is sequentially switched, and the switched command is transmitted from the second communication control device to the first communication control device.