This ppa provides DTN packages for Ubutnu. More info about DTN at dtn home page: http://www.dtnrg.org/wiki Adding this PPA to your system You can update your system with unsupported packages from this untrusted PPA by adding ppa:l3on/dtn to your system's Software Sources. (Read about installing) sudo add-apt-repository ppa:l3on/dtn sudo apt update