A configuration tool, particularly a configuration computer, for configuring at least one user-specific connection between access points of a transmission network, particularly of a highly available network, which are connectable to user-located network devices , the configuration tool comprising means for displaying a graphical representation of the transmission network on the basis of planning data about network devices of the transmission network and about links between these network devices via which the at least one user-specific connection can be established, the graphical representation containing the visualization of at least one availability criterion of the network devices and/or links.