File describing boundary conditions for transient gas networks. This contains a list of nodes with data. The additional meta information allows to specify a time, file version, etc. This contains some additional information. Mandatory is the version of the file, the date and the time interval with start, end and its unit. The network file that belongs to the boundary conditions. An optional tag to specify the author. The version of the file. The date when the file was created. The time interval (start, end, time unit) for which pressure, flow, valve status, ... is available in this file A value for the speed of sound. A value for the friction coefficient. A list of nodes for which data is provided. A specific node on the list of nodes. Information for nodes. Possible choices for nodes: boundary nodes and innodes. Can contain information on time, pressure and/or massflow. A certain timepoint that is considered. Pressure at the current node at a certain timepoint. Massflow at the current node at a certain timepoint.