Communication control device, communication control method, and non-transitory computer readable medium storing application control program

A communication control method performed by a communication control device for controlling communication between a subject device and an external device, the communication being performed via a second network by an application executed by the subject device connected to a first network different from the second network, the communication control method comprising:

• detecting occurrence of congestion on a communication line used for the communication by monitoring a state of the communication line;
• transmitting, based on the detecting the occurrence of congestion, a notification to the application that has used the communication line on which the occurrence of congestion has been detected, the notification indicating congestion on the communication line in use;
• acquiring a communication speed of the communication line;
• and
• transmitting, based on detecting the communication line with the communication speed equal to or lower than a predetermined value, a speed decrease notification to the application that has used the communication line with the communication speed equal to or lower than the predetermined value, the speed decrease notification indicating that the communication line is in a low-speed state.

A non-transitory computer readable medium storing an application control program that includes instructions for a subject device executing an application for performing data communication with an external device, the instructions being configured to, when executed by at least one processor, cause the subject device to carry out:

• receiving a message from a communication control device configured to control communication between the application and the external device, the message indicating that congestion has occurred on a communication line used for the communication with the application;
• and
• limiting the communication based on the receiving of the message indicating that congestion has occurred on the communication line;
• wherein the communication control device is configured to control communication between the application and the external device by:
• detecting occurrence of congestion on the communication line used for the communication by monitoring a state of the communication line;
• transmitting, based on the detecting the occurrence of congestion, the message to the application that has used the communication line on which the occurrence of congestion has been detected;
• acquiring a communication speed of the communication line;
• and
• transmitting, based on detecting the communication line with the communication speed equal to or lower than a predetermined value, a speed decrease notification to the application that has used the communication line with the communication speed equal to or lower than the predetermined value, the speed decrease notification indicating that the communication line is in a low-speed state.