AMPRNet

The AMPRNet (AMateur Packet Radio Network) or Network 44 is used in amateur radio for packet radio and digital communications between computer networks managed by amateur radio operators. Like other amateur radio frequency allocations, an IP range was provided in 1981 for Amateur Radio Digital Communications (a generic term) and self-administered by radio amateurs. In 2001, undocumented and dual-use of 44.0.0.0/8 as an internet telescope began. Beginning on 1 May 1978, the Canadian authorities allowed radio amateurs on the 1.25-meter band (220 MHz) to use packet radio, and later in 1978 announced the 'Amateur Digital Radio Operator's Certificate'.Discussion on digital communication amateur radio modes, using the internet protocol suite and 44/8 IPv4 addresses followed subsequently. By 1988, one thousand assignments of address space had been made.As of December 2009 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.By 2016, the European-based High-speed Amateur-radio Multimedia NETwork (HAMNET) offered a multi-megabit Internet protocol network with 4,000 nodes, covering central Europe. The use of TCP/IP on amateur radio, using packet radio networks, occurred early on in the history of the Internet and preceded the appearance of the public Internet. The class A 44/8 netblock of 16.7 million IP addresses was set aside for amateur radio users worldwide, having been secured in 1981 by Hank Magnuski; when computer networking was in its infancy and prior to Internet flag day when Network Control Program (NCP) was replaced by Transmission Control Protocol (TCP) on 1 January 1983. The initial name used by Jon Postel in Request for Comment #790 was the 'Amateur Radio Experiment Net'. Originally packet radio was used as a low level protocol for many competing higher level protocols, and TCP/IP users were essentially a minority due to the complexity of the configuration. The low baud rates also inflamed packet node site owners, as they saw the IP protocol as having too high of a protocol overhead. Very few systems operated over HF for this reason. The best solution on 1,200/9,600-baud VHF networks emerged as TCP/IP over ROSE (Radio Amateur Telecommunications Society 'RATS' Open Systems Environment, based on X.25 CCITT standard). Within just a few years the public Internet made these solutions obsolete. The ROSE system today is maintained by the Open Source FPAC linux project. The AMPRNet is connected by wireless links and Internet tunnels. Due to the bandwidth limitations of the radio spectrum, VHF and UHF links are commonly 1,200-baud, and usually restricted to a maximum of 9,600 baud. Although with the advent of mass-produced Wi-Fi equipment on 2.4 GHz and 5 GHz this technology is now being used to provide much faster links on nearby amateur frequencies. 300 baud is normally used on HF. Microwave links generally do not use packet radio, and instead use the commercial Wi-Fi access points (as high-speed multimedia radio (HSMM) or 'hinternet'). The AMPRNet fully supports TCP/IP allowing for support of all network protocols. The AMPRNet is composed of a series of subnets throughout the world. Portions of the network have point to point radio links to adjacent nodes, while others are completely isolated. Geographically dispersed radio subnets can be connected using an IP tunnel between sites with Internet connectivity. Many of these sites also have a tunnel to a central router, which routes between the 44 network and the rest of the Internet using static routing tables updated by volunteers.