JP3060660B2 - Terminal device transmission control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission control system for a terminal device. In a local area network (LAN) in which a plurality of terminal devices are connected to each other, data transmitted on a transmission path is processed by a destination terminal device, but the destination terminal is a printer device (called a low-speed device). In the case of the data output process, the destination terminal requires more processing time than the process of writing data to a magnetic disk device (referred to as a high-speed device) or the like. Occupies more time than data transmitted to a high-speed device.

As a result, in order to reduce the efficiency of data transmission requiring immediate processing to a high-speed device, there is a demand for an improvement in the efficiency of data transmission to a high-speed device.

[0003]

2. Description of the Related Art FIG. 5 shows a terminal device constituting a local area network. FIG. 5 shows a configuration in which, for example, terminal devices 61 and 62 such as workstations, a printer device 63, and a file device 64 such as a disk device are connected by a local area network (LAN).

[0004] Terminal devices 61 and 62 to transmit data.
Confirms whether the transmission path is free. This confirmation is performed by detecting a carrier (carrier) on the transmission path (called carrier detection).

It is now assumed that the terminal device 61 confirms the availability of a transmission path to transmit data to be output to the printer device 63, and starts transmitting data to the transmission path. The data transmitted to the transmission path has the configuration shown in the explanatory diagram of the frame in FIG.
Transmission / reception management is performed.

The output data from the terminal device 61 to the printer device 63 is divided into a plurality of frames, and one frame forms one transmission data. When the terminal device 62 writes data to the file device 64 while the terminal device 61 is transmitting a frame to the transmission path, the terminal device 62 performs carrier detection.
When a carrier is detected, the terminal device 62 delays the transmission in order to avoid collision between the frame transmitted by the terminal device 62 and the frame of the terminal device 61.

[0007]

A computer processing device such as a workstation having a data processing function, a printer device, a file device, and the like are connected as terminal devices to the LAN. A traffic congestion state in which the number of frames transmitted per unit time per unit time increases. Even if the amount of data of the transmission frame to each terminal device is the same, the time that a transmission frame to a low-speed device such as a printer device, which has a relatively low data processing speed, occupies the transmission path is determined by the time of a high-speed device Takes more than the occupation time of the transmission frame to
If data transmission to a high-speed device is performed during data transmission to a low-speed device, the transmission frame collides with a transmission frame to a low-speed device, so retransmission of the transmission frame to the high-speed device occurs frequently, and the transmission efficiency to the high-speed device increases. There was a problem of dropping.

An object of the present invention is to improve transmission efficiency to a terminal device requiring high-speed processing by detecting that traffic on a transmission path is congested and relaxing transmission of transmission frames by low-speed devices. I do.

[0009]

FIG. 1 is a block diagram showing the principle of the present invention. Terminal processing unit 4 including transmission processing unit 1, transmission line control unit 2, and traffic counter 25
And a terminal device 5 holding a predetermined control code 55, and a local area network 3. The terminal processing device 4 and the terminal device 5 are mutually connected via the local area network 3, When the transmission data to the terminal device 5 is designated, the transmission request to the control code 55 of the terminal device 5 is made to the transmission path control unit 2 and the control code 55 notified from the transmission path control unit 2 is transmitted. It is determined whether to perform transmission with delay control or transmission without delay control based on the following.In the case of transmission with delay control, a predetermined waiting time is provided after the data in the transmission buffer 21 is transmitted, and the next transmission data Is stored in the transmission buffer 21 and transmission is requested to the transmission path control unit 2. In the case of transmission without delay control, transmission data is stored in the transmission buffer 21 without providing a waiting time and transmission path control is performed. Part 2 The transmission path control unit 2 reads the control code 55 from the transmission destination terminal device and notifies the transmission processing unit 1 when receiving the control code 45 request from the transmission processing unit 1, and transmits the data. When there is a transmission request, the transmission data in the transmission buffer 21 is transmitted to the destination terminal device. When a carrier on the transmission path is detected, the detection frequency is accumulated in the traffic counter 25 at predetermined time intervals, and the transmission processing unit 1
And the transmission processing unit 1 performs transmission without delay control if the value of the traffic counter 25 is equal to or less than a predetermined value.

[0010]

The transmission processing unit 1 determines whether to perform transmission with delay control or transmission without delay control based on the control code 55 notified from the transmission path control unit 2, and transmits the transmission request of the transmission buffer 21. For the transmission path control unit 2.
Performs transmission without delay control if the value of the traffic counter 25 is equal to or less than a predetermined value, and
If the value of 25 exceeds a predetermined value, a predetermined waiting time is provided for a transmission request with delay control and the next transmission data is transmitted to control the traffic of the transmission frame transmitted to the transmission path. It is possible to do.

[0011]

FIG. 2 shows a system configuration diagram of the embodiment. Although a plurality of terminal devices are connected to the local area network 3, in FIG.
5-1 and the connection of the printer device 5-2 and the terminal devices 5-3,..., 5-n are shown.

The terminal processing device 4 includes a transmission processing unit 1 including a data processing unit 11, a delay control unit 12, and a timer 13,
The transmission line control unit 2, the transmission buffer 21, and the traffic counter 25 are configured, and the file device 5-1 and the printer device 5-2 are configured from the transmission line control units 510 and 520 and the control code 55, respectively (terminal device). 5-3,..., 5-n also hold the control code 55, but are not shown).

The transmission path control unit 2 of the terminal processor 4 constantly checks the presence or absence of a carrier on the transmission path. When a carrier is detected, the carrier is stored in a traffic counter (25). The value (abbreviated as traffic frequency) stored in the traffic counter (25) is notified to the data processing unit 11. After notifying the data processing unit 11, the traffic counter (25) is cleared and carrier detection in the next cycle starts.

When the notified traffic frequency exceeds a predetermined value, the data processing unit 11 determines that the traffic volume (the number of transmission frames) of the transmission line is large, and determines the low speed of the printer device 5-2 or the like. For sending data to the device,
The transmission request to the transmission path control unit 2 is performed with a predetermined time interval delayed. The transmission procedure of this series of transmission frames will be described with reference to the data transmission procedure of the embodiment of FIG.

In FIG. 3, in a processing step 81, the data processing unit 11 stores transmission data in the transmission buffer 21, specifies a destination terminal, and issues a transmission request to the transmission path control unit 2.
The transmission path control unit 2 checks the availability of the transmission path by performing carrier detection, and waits for the availability of the transmission path when a carrier is detected. Processing steps if the transmission path is free
At 82, the transmission path control unit 2 reads the control code 55 of the designated destination terminal from the destination terminal.

When reading the control code 51, if the destination terminal is the printer device 5-2, the transmission line control unit 2 requests the transmission line control unit 520 to transmit the control code 55, and the transmission line control unit 520 This is performed by receiving the control code 55 transmitted from the PC and passing it to the data processing unit 11.

In processing step 83, the data processing section 11 receives the control code 55 and stores it in the control code storage section 14. In processing step 84, the transmission path control unit 2 sends out a transmission frame composed of data in the transmission buffer 21 to the transmission path.
In processing step 85, the data processing unit 11 checks whether or not there is delay control based on the control code 55. The control code 55 for a low-speed processing device such as a printer device is set to have delay control, and the control code 55 for a high-speed processing device
Is set without delay control.

If the result of the check is that there is delay control, the data processing unit 11 determines in step 86 that the transmission path control unit 2
Checks the value of the traffic counter notified from the server. If the value is equal to or less than a predetermined value (determined that the frame being transmitted on the transmission path is not congested), the transmission without delay control is performed in processing step 89, and If the value exceeds the value, the data processing unit 11 specifies the delay time until the transmission request is made and notifies the delay control unit 12 in the processing step 87.

Next, in processing step 88, the delay control unit 12 sets the delay time in a timer, and when the delay time has elapsed, detects a timer interrupt and notifies the data processing unit 11 of it. In processing step 89, the data processing unit 11 stores the next transmission data in the transmission buffer 21 and requests the transmission path control unit 2 to transmit. The transmission request made according to the above procedure is performed until all data transmission requests are completed.

When there is no delay control, a transmission request is made without providing a delay time.

[0021]

According to the present invention, the transmission processing unit 1 includes a traffic counter.
Determine whether to perform delay control by checking the value of 25, if the traffic on the transmission line exceeds a predetermined amount,
Transmission of a frame to a low-speed device to a transmission path can be reduced by providing a delay time, and transmission efficiency to a terminal device that requires high-speed processing can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the principle of the present invention.

FIG. 2 is a system configuration diagram of an embodiment.

FIG. 3 is a data transmission procedure according to the embodiment;

FIG. 4 is an explanatory diagram of a transmission frame.

FIG. 5 is a terminal device constituting a local area network 1 is a transmission processing unit, 11 is a data processing unit, 12 is a delay control unit, 13
Is a timer, 14 is a control code storage unit, 2,510,520 is a transmission line control unit, 21 is a transmission buffer, 25 is a traffic counter, 3,60 is a local area network, 4 is a terminal processing unit, 5,5-3,. .., 5-n, 61,62 are terminal devices, 5-1,64 are file devices, 5-2,63 are printer devices,
55 represents a control code, and 81 to 89 represent processing steps.

Claims (2)

(57) [Claims] 1. A terminal processing device (4) comprising a transmission processing unit (1), a transmission line control unit (2), a traffic counter (25), and a terminal holding a predetermined control code (55). A terminal processor (5) and a local area network (3), wherein the terminal processing device (4) and the terminal device (5) are mutually connected via the local area network (3); ), When transmission data to the terminal device (5) is designated, sends a request to the transmission line control unit (2) to acquire the control code (55) of the terminal device (5). The control code (55) notified from (2)
It is determined whether the transmission has the delay control or the transmission without the delay control based on the following. In the case of the transmission having the delay control, a predetermined waiting time is provided after the data in the transmission buffer (21) is transmitted and the next The transmission data is stored in the transmission buffer (21), and transmission is requested to the transmission path control unit (2). In the case of transmission without delay control, the transmission data is stored without any waiting time in the transmission buffer (21). ) And requests transmission to the transmission path control unit (2). When the transmission processing unit (1) receives a request to acquire the control code (45) from the transmission processing unit (1), the transmission path control unit (2) The control code (55) is read from the terminal device and notified to the transmission processing unit (1). When there is a data transmission request, the transmission data in the transmission buffer (21) is transmitted to the destination terminal device. Transmission control method of the terminal device. 2. In a terminal device (4) connected via a local area network (3), when a transmission line control unit (2) detects a carrier on a transmission line, the transmission line control unit (2) changes the detection frequency at every predetermined time interval. The information is accumulated in the counter (25) and notified to the transmission processing unit (1), and the transmission processing unit (1) performs transmission without delay control if the value of the traffic counter (25) is equal to or less than a predetermined value. The transmission control method for a terminal device according to claim 1, wherein