ns3 3.29+dfsg-3 (arm64 binary) in ubuntu focal

 ns-3 is a discrete-event network simulator for Internet systems,
 targeted primarily for research and educational use.
 ns-3 is free software, licensed under the GNU GPLv2 license,
 and is publicly available for research, development, and use.
 ns-3 is intended as an eventual replacement for the popular
 ns-2 simulator. The project acronym “nsnam” derives
 historically from the concatenation of ns (network simulator)
 and NAM (network animator).
 .
 This package contains several utilities. The files for development
 are in libns3-3, libns3-dev and python-ns3.