AARNet was initially built as a multi-protocol network, comprising Internet Protocol (IP) as well as DECnet and X.25 so as to accommodate pre-existing ACSnet and SPEARnet systems then in current use.

Australian National University staff members Geoff Huston and Peter Elford were seconded by the AVCC in 1989 and tasked with technical management and build of the new network.

[13] The AARNet4 national network comprises high capacity optical fibre transmission paths between switching centres in major cities from Cairns to Perth as well as branch lines to Darwin, Hobart and several other locations.

This policy applies to all requests for settlement-free interconnection with AARNet, either via dedicated connections or traffic via public internet exchanges.

AARNet provides the Internet to several million end-user devices at Australian universities, CSIRO, various other research and educational institutions, and some hospitals.

Prior to that, and at other locations, it is end-customer institutions' responsibility to extend services to site and to provision their own inter-campus network links.

These are either operated directly by AARNet such as in Queensland or provided by companion networks such as SABRENet in South Australia and VERNet in Victoria.

AARNet has high capacity interconnections with North American[16][17] (Internet2), European[18] (GÉANT) and Asian[19] (TEIN3) components of the global network.

For example, to interconnect major research instruments such as synchrotrons and telescopes in remote locations to high performance computer systems and researchers around the world, such as astronomers in Europe viewing the southern sky using telescopes in Australia[25] or high resolution realtime video links between remote locations.

[26] Most recently, AARNet has built a 100 Gbit/s WDM optical fibre transmission system[14] from Perth to Geraldton and on to the Murchison Radio-astronomy Observatory (MRO) in Western Australia in support of Australia's component of the international Square Kilometre Array project and the initial ASKAP telescope array at the MRO.