A communication system comprising a first node (100, 200) and a second node (200, 300) that is connected to the first node (100, 200), wherein: the first node (100, 200) is a central unit, CU, and the second node (200, 300) is a distributed unit, DU; or the first node (100, 200) is a DU and the second node (200, 300) is a remote unit, RU, wherein the second node (200, 300) includes a transmitter (210, 310) configured to transmit, when the second node (200, 300) is connected to the first node (100, 200), function identification information for identifying functions installed in the second node (200, 300), the first node (100, 200) includes a receiver (110, 240) configured to receive the function identification information transmitted from the second node (200, 300), and a processor (120, 220) that is connected to the receiver, and the processor (120, 220) is configured to execute a process including deciding, based on the function identification information, a function to be enabled or disabled out of the functions installed in the second node (200, 300), selecting at least a test item used for verifying the function that is decided to be enabled, conducting a test of the selected test item, notifying a result of the test to the second node (200, 300), and starting, when obtaining a test result indicating that the function that is decided to be enabled is normally operated, a service that uses the function, wherein: for each selected test item, an operation test including transmission and reception of a signal between the first node (100, 200) and the second node (200, 300) is conducted; the receiver (110, 240) is configured to receive verification completion information indicating a test item for which verification has already been completed in the second node (200, 300); and the selecting includes selecting, based on the verification completion information, a test item for which verification has not been completed out of test items used for verifying the function that is decided to be enabled. the first node (100, 200) is a central unit, CU, and the second node (200, 300) is a distributed unit, DU; or the first node (100, 200) is a DU and the second node (200, 300) is a remote unit, RU, the second node (200, 300) includes a transmitter (210, 310) configured to transmit, when the second node (200, 300) is connected to the first node (100, 200), function identification information for identifying functions installed in the second node (200, 300), the first node (100, 200) includes a receiver (110, 240) configured to receive the function identification information transmitted from the second node (200, 300), and a processor (120, 220) that is connected to the receiver, and a receiver (110, 240) configured to receive the function identification information transmitted from the second node (200, 300), and a processor (120, 220) that is connected to the receiver, and the processor (120, 220) is configured to execute a process including deciding, based on the function identification information, a function to be enabled or disabled out of the functions installed in the second node (200, 300), selecting at least a test item used for verifying the function that is decided to be enabled, conducting a test of the selected test item, notifying a result of the test to the second node (200, 300), and starting, when obtaining a test result indicating that the function that is decided to be enabled is normally operated, a service that uses the function, deciding, based on the function identification information, a function to be enabled or disabled out of the functions installed in the second node (200, 300), selecting at least a test item used for verifying the function that is decided to be enabled, conducting a test of the selected test item, notifying a result of the test to the second node (200, 300), and starting, when obtaining a test result indicating that the function that is decided to be enabled is normally operated, a service that uses the function, for each selected test item, an operation test including transmission and reception of a signal between the first node (100, 200) and the second node (200, 300) is conducted; the receiver (110, 240) is configured to receive verification completion information indicating a test item for which verification has already been completed in the second node (200, 300); and the selecting includes selecting, based on the verification completion information, a test item for which verification has not been completed out of test items used for verifying the function that is decided to be enabled.