AMPRNet

In 2001, undocumented and dual-use of 44.0.0.0/8 as a network telescope began,[1] recording the spread of the Code Red II worm in July 2001.

[2][3] Discussion on digital communication amateur radio modes, using the Internet protocol suite[4] and 44/8 IPv4 addresses followed subsequently.

[5] As of December 2009[update] approximately 1% of inbound traffic volume to the 44/8 network was legitimate radio amateur traffic that could be routed onwards, with the remaining 2‒100 gigabyte per day of Internet background noise being diverted and logged by the University of California San Diego (UCSD) internet telescope for research purposes.

In 1981, Hank Magnuski obtained the class A 44/8 netblock of 16.7 million IP addresses for amateur radio users worldwide.

One approach for 1,200/9,600-baud VHF/UHF operation emerged as TCP/IP over ROSE (Radio Amateur Telecommunications Society "RATS" Open Systems Environment, based on X.25 CCITT standard).

Since it is based on IP, the AMPRNet supports the same transport and application protocols as the rest of the Internet, though there are regulatory restrictions on encryption and third-party traffic.

[11][14][15][16] By 1996 higher-speed 56k modems briefly had greater throughput than was possible to forward via the "mirrorshades" central reflector router and back again.

[17] Only IP addresses with an active Domain Name System (DNS) entry under ampr.org are passed by the packet filter for forwarding.

[1] Beginning in February 2001,[1][22][23][24] as part of backscatter research and the CAIDA/UCSD network telescope project, the whole of the 44/8 address block[25] was being advertised via the border gateway protocol (BGP) as a passive honeypot for Internet background noise and backscatter collection,[24][26] based in the Center for Applied Internet Data Analysis[note 1] at the San Diego Supercomputer Center.

[25][37][38] As of 2016[update], the 44/8 network was receiving backscatter from Denial-of-Service attacks (DoS) each measuring ~226 packets per second (mean peak average)[39] totalling 37 terabytes per month.

[24] The project funding proposal for "Sustainable Tools for Analysis and Research on Darknet Unsolicited Traffic" (STARDUST) specified a planned upgrading to 10 Gigabit Ethernet with a passive optical tap, in order to provide finer timestamping and avoid packet loss.

[25] As of 31 December 2017[update], the overall total collected by the UCSD Network Telescope stood at 3.25 petabytes (uncompressed), stored across 129,552 hourly files.

[25] Users of the collected data up to 2012 are requested to acknowledge that "Support for Backscatter Datasets and the UCSD Network Telescope is provided by Cisco Systems, Limelight Networks, the US Department of Homeland Security, the National Science Foundation, DARPA, Digital Envoy, and CAIDA Members.

"[46] The original Class A network allocation for amateur radio was made in the 1970s,[47] and recorded in September 1981,[7] which consisted of ~16 million IP addresses.

[51] On 18 July 2019, the designation recorded by Internet Assigned Numbers Authority was altered from "044/8 Amateur Radio Digital Communications"[52] to "044/8 Administered by ARIN".

[56] Prior to sale, addresses in the 44.192/10 block had been allocated to amateur radio areas for the outer space-amateur radio satellite service,[58][59][60] to roaming,[60] Oceania,[58][59][60] Antarctica,[58][59][60] the Arctic,[58][59][60] Italy for Centro Italiano Sperimentazione ed Attività Radiantistiche (CisarNet)[61][62] Germany for Stuttgart/Tübingen,[63] Eppstein,[63] plus the Germany/pan-European Highspeed Amateur-radio Multimedia NETwork [de] (HAMNET).

[72] During early 1993 the committee and ARRL board of directors were working on guidelines for semi-automatic digital stations, with the proposals passed to the Federal Communications Commission.

In February/March 2020, the Center for Networked Systems (CNS) of the University of California, San Diego (UCSD) received $225,000, given by ARDC to allow financial endowment of a student scholarship in the name of Alan Turing and honouring Brian Kantor.

[83] In November 2021, ARDC awarded a five-year grant, for a total of $1.3 million, to support US-based activities around Amateur Radio on the International Space Station (ARISS-USA).

[84] In January 2022, the Internet Archive received a grant of $0.9 million for assembling a Digital Library of Amateur Radio and Communications (DLARC).