JPH05336209A - Response time monitor control system - Google Patents

Abstract

PURPOSE:To adaptively update the response monitoring time of a communication protocol by measuring the response time which is affected by the operating state of a data communication system and a network circuit route by means of a response time measurement message. CONSTITUTION:The data communication systems 1 and 2 contain the clock control parts 11 and 21 which produce the time signals, the data communication control parts 12 and 22 which perform the communication control, and the response time measuring parts 13 and 23 which measure the response time covering the transmission through the reception of data respectively. The parts 12 and 22 include the data communication parts 121, 221 which perform the communication control for transmission/reception of the normal messages, the response time monitoring parts 122, and 222 which measure the response time and the response monitoring time for the communication control, and the special transmission/reception parts 123 and 223 which transmit and receive the response time measurement messages for measurement of the response time respectively. Then the parts 122 and 222 update the response monitoring time of a communication protocol based on the measurement result of the response time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a response monitoring time control system for changing a response monitoring time on a communication protocol in a data communication system in accordance with an operating condition.

[0002]

2. Description of the Related Art Conventionally, in response monitoring time control in a communication protocol, the setting of the response monitoring time is fixedly determined for each data communication system of the other party, regardless of which route on the network line is used. However, in recent years, network lines have become complicated not only through dedicated lines but also through satellite relay, submarine cables, communication services, etc., and the response time may be affected by the operational status of the data communication system or the network line path. Became. Therefore, if the response monitoring time is fixed and determined, inconvenience also occurs in the communication protocol.

[0003]

In the conventional response monitoring time control described above, when relay / transfer is performed on the network line, the response monitoring time is fixed when passing through a route with a low data transmission rate. Since it is determined, the response monitoring time may time out before the data arrives at the partner data communication system or even while the reply from the partner data communication system is in the network.

Therefore, when retransmission is performed due to a time-out, a situation occurs in which two identical data exist on the network. In addition, the receiving side receives the same data twice. Furthermore, when the response is remindered, the sender receives the response twice. In particular, the above-mentioned events may appear significantly depending on the way of selecting the route of the network line. The connection with the data communication system of the same partner does not always use the same path, and the individual data communication systems do not care what the path selected each time the connection is established. In addition, recently, a communication path via a communication satellite is often used, and in the case of using the communication satellite, it takes about 0.25 seconds for the transmission data to reach the partner data communication system. It takes 0.5 seconds for a round trip to receive a response. The propagation time becomes even longer after passing through the communication satellite several times. Also, if the network lines themselves are composed of connections between network lines, the time it takes for the transmitted data to reach the partner data communication system is greatly affected by the ability of the relay device (gateway) that connects the network lines. It CCITT Recommendation X. 25, etc., as a facility,
There is a throughput put class, but this is for how much data can process the transferable data per second, and how much time each individual data actually transmits to the partner data communication system. It does not indicate whether it will arrive.

[0005]

A response time monitoring control system of the present invention time-monitors a response time from a partner data communication system when a data communication system connected through a network line performs data communication according to a communication protocol. In the response time monitoring control system for monitoring the operation status of the data communication system of the other party and the network line by doing so, clock control means for generating a time signal for monitoring the response time, and the data communication system of the other party Response time measuring means for measuring the response time according to the time signal, and data communication control means for communicating with the data communication system of the other party in accordance with the communication protocol. The data communication control means includes the data communication. Send and receive regular messages in Data communication means, special transmission / reception means for transmitting / receiving a response time measurement message for measuring the response time, and the operating state of the partner data communication system and the network line by the time monitoring of the response time. And a response monitoring means for updating the response monitoring time defined in the communication protocol by the time measurement, and the response monitoring time on the communication protocol for the data communication system of the other party and the Change according to the operation status of the network line.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. Referring to FIG. 1 showing a configuration of an embodiment of the present invention, a data communication system 1 and a data communication system 2
Are connected through the network line 3. And
Clock controls 11 and 12 for generating a time signal,
Data communication control units 12 and 22 for controlling communication and response time measuring units 13 and 14 for measuring response time from data transmission to reception are provided, respectively. The data communication control units 12 and 22 include data communication units 121 and 221 that perform communication control of normal message transmission / reception,
Response time monitoring units 122 and 222 for performing time monitoring and response monitoring time updating in communication control, and special transmission / reception units 123 and 223 for transmitting / receiving a response time measurement message for measuring response time are provided, respectively.

Further, referring to FIG. 2 showing the format of the response time measurement message 27, the response time measurement message 27
It is composed of an identifier 28 indicating that the response time is measured, a counter 29 indicating how many times the response time measurement message 27 is received, and time information 30 indicating the transmission time.

When the data communication system 1 measures the response time with the data communication system 2, the response time measuring unit 13 receives the time signal indicating the internal time from the clock control unit 11, and the data communication control unit 12 receives the time signal. Special transceiver 12
3 is requested to transmit the response time measurement message 27, and the internal time obtained from the clock control unit 11 is stored as the transmission time. When the special transmission / reception unit 223 receives the response time measurement message 27, the data communication control unit 22 of the data communication system 2 notifies the response time measurement unit 23 of the reception of the response time measurement message 27. Response time measurement unit 2
In No. 3, since the received response time measurement message 27 is not a response to the response time measurement message 27 transmitted by itself, the special transmission / reception unit 223 of the data communication control unit 22 is requested to return the received response time measurement message 27. The data communication control unit 12 of the data communication system 1 receives the reply of the response time measurement message 27 from the special transmission / reception unit 223. Then, the special transmission / reception unit 123 notifies the response time measurement unit 13 of the reception of the reply of the response time measurement message 27. The response time measuring unit 13 is a response of the received response time measuring message 27 to the response time measuring message 27 transmitted by itself, so that the clock control unit 1
The clock signal of the internal time is received from 1. Response time measurement unit 1
3 uses the internal time obtained from the clock control unit 11 as the reception time, and calculates the response time based on the difference from the stored internal time of transmission. The response time monitoring unit 122 of the data communication control unit 12 updates the response monitoring time on the communication protocol based on the response time obtained by the measurement.

When the data communication system 2 requests the data communication system 1 for the response monitoring time, the same operation as described above is performed.

Next, when measuring the response time, regarding the communication of the response time measurement message 27, JISX510
A case where the present invention is applied to a balanced asynchronous mode class (BAC) of a high level data link (HDLC) control procedure defined by 4, X5105, X5106, etc. will be described as an example.

Referring to FIG. 3 showing the frame of the response time measurement message 27 used in the above-mentioned HDLC, the HDLC frame 31 storing the frame information section 32 is surrounded by flags 33 and 38 indicating the beginning and end of the frame. , Address field 3 indicating source or destination
4, a control field 35 indicating that it is an operation command or a response, an information field 36 for storing information for data transmission, and a frame check sequence 37 which is frame transmission error check data. The frame 31 for transmitting the response time measurement message 27 is transmitted with the response time measurement message 27 shown in FIG. 2 stored in the information field 36.

2 connected through a network line 3
When the two data communication systems 1 and 2 measure the response time, referring to FIG. 4 showing the order of communication of the response time measurement message 27, the frame 31 transmitting the response time measurement message 27 has no frame sequence number. An unnumbered UI (unnumbered information) frame is used. When the data communication system 1 and the data communication system 2 are connected via a network line, the data communication system 1 transmits a UI frame 41 of a response time measurement message (measurement data) to the data communication system 2. The data communication system 2 responds to the received UI frame (measurement data) 41 with a UI frame (response data) having the same information as the UI frame (measurement data) 41 as a response.
42 to the data communication system 1. When the data communication system 1 receives the UI frame (response data) 42 from the data communication system 2, the elapsed time t1 from the time when the UI frame (measurement data) 41 is transmitted is calculated from the difference between the stored transmission time and reception time. The response monitoring time is calculated by the response time measuring unit 13, and the response monitoring time is updated by the response monitoring unit 122 based on t1. Similarly, the data communication system 2 transmits a UI frame (measurement data) 43 to the data communication system 1. In response to the received UI frame (measurement data) 43, the data communication system 1 transmits, as a response, a UI frame (response data) 44 having the same information as the UI frame (measurement data) 43 to the data communication system 2. When the data communication system 2 receives the UI frame (response data) 44 from the data communication system 1, the UI frame (measurement data) 4
3, the elapsed time t2 from the time when 3 is transmitted is calculated, and t2
The response monitoring time is updated based on

When the response monitoring time is updated, an operation command (SABM) and a response (UA) thereto are transmitted / received by the data communication units 121 and 221 to communicate a normal message. After a lapse of a certain time, the update of the response monitoring time adapted to the change in the operating state of the communication systems 1 and 2 and the network line 3 is started.

When the response review time interval T1 in the data communication system 1 is reached, the UI frame (measurement data) 47 is transmitted again to the data communication system 2 when T1 elapses from the time when the response monitoring time is obtained. In response to the received UI frame (measurement data) 47, the data communication system 2 responds to the UI frame (measurement data) 47 with the same information as the UI frame (measurement data) 47.
48 to the data communication system 1. When the data communication system 1 receives the UI frame (response data) 48 from the data communication system 2, the data communication system 1 calculates the elapsed time t3 from the time when the UI frame (measurement data) 47 is transmitted, and again based on t3, the response monitoring time. Update and set again.

[0015]

As described above, according to the present invention, the response time measurement message is exchanged, the response time of the data communication system including the data transmission time is measured, and the response in the communication protocol is based on the measured response time. The monitoring time can be set appropriately. As a result, no message that violates the communication protocol is transmitted to the network line. Further, since each data communication system does not wait for a monitoring time longer than necessary and unnecessary retransmission is performed, efficient data transmission can be performed.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a format of a response time measurement message for setting a response monitoring time.

FIG. 3 is a diagram showing an HDLC frame format of a response time measurement message.

FIG. 4 is a diagram showing a communication sequence of a response time measurement message between data communication systems.

[Explanation of symbols]

1 data communication system 2 data communication system 3 network line 11 clock control unit 12 data communication control unit 13 response time measurement unit 21 clock control unit 22 data communication control unit 23 response time measurement unit 27 response time measurement message 28 measurement data or response data Identifier 29 number of times of response time measurement message transmission 30 time information 31 HDLC frame 32 frame information part 33 flag 34 address field 35 control field 36 information field 37 frame check sequence 38 flag 41 UI frame (measurement data) 42 UI of response time measurement message Frame (Response Data) 43 UI Frame (Measurement Data) 44 UI Frame (Response Data) 45 Operation Command (SABM) 46 Response (UA) 47 UI Frame (Measurement Data) 48 UI frame (response data) 121 data communication unit 122 response monitoring unit 123 special transmission unit 221 data communication unit 222 response monitoring unit 223 special transmission unit

Claims (2)

[Claims] 1. When a data communication system connected through a network line performs data communication in accordance with a communication protocol, the response time from the data communication system of the other party is time-monitored so that the data communication system of the other party and the network line can be connected. In a response time monitoring control system for monitoring an operating state, a clock control means for generating a time signal for monitoring the response time, and a response time measurement for measuring the response time of the partner data communication system by the time signal. Means, data communication control means for performing communication with the data communication system of the other party in accordance with the communication protocol, wherein the data communication control means includes data communication means for transmitting and receiving a normal message in the data communication, and the response. A response for measuring time The special transmission / reception means for transmitting / receiving a time measurement message, and the time monitoring of the response time, monitor the operational status of the other party's data communication system and the network line, and set the response monitoring time defined in the communication protocol. Response monitoring means for updating by time measurement, and changing the response monitoring time on the communication protocol in accordance with the operating conditions of the data communication system of the other party and the network line. Response monitoring time control system. 2. The response monitoring time control system according to claim 1, wherein the response monitoring time control message is transmitted and received at regular intervals to update the response monitoring time.