JPS6231237A - Communication control equipment - Google Patents

Abstract

PURPOSE:To avoid the occurrence of the abort due to the occurrence of the underrun and to minimize the increase in the delay in the equipment of the sending data by inserting the speed variable code into the data sent to the line when the host processing equipment comes to be the congestion condition. CONSTITUTION:When a host processing equipment 1 comes to be the congestion condition, by the delay time of the response to the request of the transmitting data from a communicating control equipment 2 of the high level data link, a congestion deciding circuit 4 detects the congestion condition of the processing equipment 1 through a connecting line 5, drives an inserting circuit 6 of the speed variable code and instructs the insertion of the speed variable code. For such a reason, the data sending sped to the line can be temporarily decreased until the congestion condition of the processing equipment 1 is released. When a removing circuit 5 of the speed variable code detects the speed variable code inserted into the receiving data from an opponent station through a line 14, the speed variable code is removed, and thereafter, the receiving data are assembled, and sent to the communication control device 2 of the high level data link through a connecting line 10.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a communication control device for high-level data links, and in particular to a communication control device that can avoid underrun conditions caused by M in a host processing unit. It is related to.

[Conventional technology]

Conventionally, this type of high-level data link communication control device aborts the transmitted data (sequential transmission of 7 or more 1)
By doing so, the other station was notified and the transmitted data was retransmitted.

[Problem that the invention seeks to solve]

The above-mentioned high-level data link communication control device aborts the data being sent and retransmits it according to the high-level data link control procedure when an underrun occurs due to congestion in the upper processing device. By this,
There was a problem in that the delay within the device for sending data increased.

[Means for solving problems]

The communication control device according to the present invention detects when a higher-level processing device is in a congested state, and inserts a rate-variable code into data sent to a line, thereby adjusting the data transmission speed to the line to a higher-level processing unit. This is to temporarily lower the power level until the congestion state of the device is released.

[Effect]

In the present invention, it is possible to avoid the occurrence of an appoint due to the occurrence of an underrun, and to minimize the delay within the device for sending data.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of a communication control device according to the present invention. In the figure, 1 is a host processing device, 2 is a communication control device connected to the host processing device 1 via a connection line 3 and has a constant high level data link, and 4 is a communication control device connected to the host processing device 1 via a connection line 5. Connected radiation determination circuit, 6
9 is a speed variable code insertion circuit connected to the communication control device 2 through all the connection lines 7 and connected to the congestion determination circuit 4 through the connection line 8;
A connecting line 11 is connected to the convergence determining device 4 via a connecting line 11.
This is a speed variable code removal circuit connected through a speed variable code removal circuit. 12 is a connection line connected between the communication control device 2 and the congestion determination circuit 4; 13 is a connection line connected between the speed variable code insertion circuit 6 and a line (not shown); Reference numeral 14 denotes a connection line connected between the speed variable code removal circuit 9 and a line (not shown). However, the variable speed code is a code in which a series of 1's that are normally determined as an abort is sandwiched between 0's before and after, and the number of 1's is arbitrarily determined. however,
Since consecutive 1's in the number of speed variable codes are removed by the speed variable code removal circuit 6 during reception, they cannot be aborted and used.

Next, the operation of the communication control device with the above configuration will be described, particularly the operation when the host processing device 1 enters the congestion state. First, when the upper processing device 1 enters a congestion state,
The congestion determination circuit 4 detects the congestion state of the host processing device 1 via the connection line 5 based on the delay time of a response to a request for transmission data from the communication control device 2 of the high-level data link. When the congestion determination circuit 4 detects the congestion state of the host processing device 1, it drives the variable speed code insertion circuit 6 via the connection line 8 and instructs the insertion of the variable speed code. Therefore, the insertion circuit 6 inserts a speed variable code into the transmission data sent from the communication control device 2 of the high-level data link via the connection line T, and transmits it to the connection line 13.
to the line via. With this determination, the data transmission speed to the line can be temporarily lowered until the high-level processing device 1 is released from the sniffing state. The width steepness determination circuit 4 determines the insertion interval of the speed variable code depending on the degree of convergence of the host processing device 1, and instructs the speed variable code insertion circuit 6 via the connection line 8. Next, when the VC1 speed variable code removal circuit 5 detects the speed variable code inserted into the received data from the partner station via circuit #J14, it removes this speed variable code, assembles the received data, and connects. It is sent via line 10 to the communication control unit 2 of the high-level data link.

〔Effect of the invention〕

As explained in detail above, according to the communication control device according to the present invention, by inserting a speed variable code into the data sent to the line when the host processing unit is in a congested state, data to the line is It is possible to temporarily reduce the sending speed until the congestion state of the upper processing device is cleared, and it is possible to avoid the occurrence of apex due to the occurrence of underrun, and to minimize the increase in the delay in the sending data within the device. There are effects such as

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a communication control device according to the present invention. 1... Upper processing device, 2... Communication control device, 3
... Connection line, 4 ... Congestion judgment circuit, 5 ...
Connection line, 6...insertion circuit, 7-work 8...connection line, 9...removal circuit. 10-14... Connection line.

Claims (1)

[Claims] A congestion judgment circuit detects the congestion state of the upper processing unit and instructs the insertion of a variable speed code, and the congestion judgment circuit inserts the variable speed code into the data sent to the line based on the instruction to insert the variable speed code from the congestion judgment circuit, and sends the variable speed code to the line. an insertion circuit that lowers the data transmission speed of the other station, and a removal circuit that removes the speed variable code and assembles the received data when it detects the speed variable code inserted into the received data from the other station. A communication control device characterized in that data is transferred using a transmission procedure.