Algorius Net Viewer Manual
To add a new line to the network map, press the Draw Line button on the toolbar or press the Ctrl+L button. The map editor arrow cursor will become a cross cursor, showing the drawing mode is activated. Clicking on the network map will create the first vertex of the line and the next click will correspondingly set its second vertex. Following this, the connection line will be created and added to the network map.
The drawing mode will remain active after you draw a line, so that you can just add one more line.