This invention provides a communication apparatus, which designates, when a line designated as that used for a specific application falls into a disabled state, another line as a new line used for the specific application. To accomplish this, even when at least one of a plurality of lines falls into a disabled state, and when the line in the disabled state is designated as a line used for the specific application, the communication apparatus designates a line other than the line in the disabled state among the plurality of lines as a new line used for the specific application.