A first node (10) and a second node (12) are configured for the transfer of data between them. The second node (12) is configured to determine an extent to which the second node (12) will be available for a prospective transfer (16) of data (e.g., application data) to or from the second node (12). The second node (12) is configured to transmit to the first node (10) control signaling (20) (e.g., application-layer control signaling (20)) that indicates the determined extent. The first node (10) is configured to determine, based on the control signaling (20), whether and/or when to proceed with the prospective transfer (16) of data.