Did you know that amateur radio operations have access to our own dedicated, globally accessible, IP network? We do! AMPRNet, sometimes colloquially called 44Net, is a large space of IP address space reserved exclusively for use by hams. It is administered by Amateur Radio Digital Communications, a non-profit organization dedicated to the advancement of amateur radio.

It is also a ridiculously underutilized resource. Every radio amateur ought to request an allocation; seriously, there is no reason not to, and most of the space is simply going to waste. Get your allocation now!

Brief History of the Internet and AMPRNet

In the beginning was the ARPANET, an experiment in wide-are packet-switched computer networking. Starting under the auspices of the US Department of Defense’s Advanced Research Projects Agency (ARPA), ARPANET was the prototype for what would become the modern Internet.

For background Information, I highly recommend the book, Where Wizards Stay Up Late: The Origins of the Internet by Katie Hafner and Matthew Lyon. Also, the contemporary 1972 documentary, Computer Networks: The Heralds of Resource Sharing gives a wonderfully prescient view into the early days of computer networking. The early ARPANET designers foresaw almost everything we take for granted on the Internet of today, including cloud computing!

The ARPANET project was a great success, and several years into it, the focus turned to inter-networking: that is, networking networks of computers, bridging them together into an inter-network, or “internet”. An intense period of research and design starting in the late 1970s lead to the development of the Internet Protocol suite in the 1980s. The so called TCP/IP suite consisted of a set of layered protocols with the the Internet Protocol and its adjacent Internet Control Message Protocol sitting on top of even lower-level device and link layer protocols, with the higher-level Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) layered on top of IP. These formed the basis for application-level protocols such as TELNET and FTP on top of TCP, and the Domain Name Service on top of UDP. TCP/IP emerged as a US Department of Defense standard in 1983, with version 4 of the Internet Protocol (IP or IPv4).

As this was happening, a forward-thinking ham by the name of Hank Magnuski, KA6M, thought it might be interesting to try and use TCP/IP over amateur radio, so he wrote to Jon Postel, the Internet Assigned Numbers Authority at the time, asking for an IP network allocation for amateur radio. Postel gave the “class A” IP network 44 to Magnuski for experimental amateur radio use. Thus was born 44Net, so named because its IP addresses start with the number 44.

It’s probably worth mentioning at this point that IPv4 uses addresses that are always 32-bits long and divided into a host and network portion: the higher order bits define the network, and the low order bits identify a host on that network. In the historical Internet class-based routing scheme, a “class-A” network meant the first 8 bits were reserved for the network address, while the bottom 24 bits were the host portion; 24 bits allows 2^24 or roughly 16.7 million addresses. For comparison, addresses on the early ARPANET were limited to 256.

Since the Internet started out as a US government-funded research project, it was not initially approved for commercial use. However, the this changed during the Clinton administration, with the Telecommunications Act of 1996. Opening the Internet to commercial applications led to an explosion of use and accelerating demand for IP addresses, which soon became scarce. Various techniques were used to relieve the pressure on available IP address space, including the elimination of class-based routing and pervasive use of Network Address Translation (NAT), but demand for IPv4 increased exponentially and IP addresses became a very valuable commodity.

Through this time, we hams kept our allotment of the network. Ownership of the segment moved from Magnuski through a series of individuals and culminated in the transfer to the Amateur Radio Development Corporation, forerunner of the modern ARDC. A group of volunteers took care of the administrative duties, allocating subnetworks to interested radio amateurs, establishing peering points with the rest of the Internet, etc.

However, AMPRNet remained an absurdly underutilized resource: out of the more than 16 million available address, never more than about 40,000 have been allocated; out of those allocated, only a fraction have been used (most hams are allocated a minimum of 256 addresses by default). As demand for IPv4 address space grew commercially, ARDC was sitting on a goldmine.

In 2019, ARDC made the decision to sell one quarter of the AMPRNet address space, at a rate of about USD $25 per IP address, or roughly $100 million USD. That money was then put into a non-profit, the present ARDC, for distribution to the community in the form of grants, scholarships, etc.

Hams never shying about from a good kvetch, this caused quite a kerfuffle in the 44Net community. However, the money is being put to good use, and in this author’s opinion, this was the most impactful thing to do with the space. Like our spectrum, we use it or lose it and we weren’t using it (hence why I encourage all hams to get an AMPRNet allocation!). As an aside, ARDC minimizes its tax burden by claiming the remaining 44Net address space as an asset they are distributing to hams: if that were not the case, they would basically have to keep selling parts of it off until it was gone. This is another reason to get an allocation if you don’t already have one!

For more details on the history of AMPRNet and the sale, the ARDC has put together a page.

So What Can I Do With It?

Okay, so I’ve convinced you that you want — nay, need — an AMPRNet allocation. You’ve headed on over to the 44Net wiki and learned how to get access to the portal and gotten yourself an allocation.

Next you set up a router running OpenBSD and configured it as an AMPR gateway. You’re passing traffic with other AMPRNet networks and the Internet. Congratulations!

Now what do you do with this?

It’s cliche, but essentially anything: the possibilities are nearly endless. You can basically set up a parallel Internet. For instance, you could send and receive email using the same standardized protocols used on the Internet at large, but without relying on commercial Internet infrastructure. Similarly, you can run web servers, login between AMPRNet attached hosts, tunnel AX.25 over IP over AMPRNet, provide instant messaging services, or make use of real-time communication using IRC or the venerable Unix talk program. Almost anything you can do on the Internet at large you can do on AMPRNet, as long as you follow applicable regulations when transmitting over RF. Real-time voice and streaming video? Yes! Your only limits are your imagination and part 97.

Example: HamWAN

That all sounds great in theory, but a real-world example might be illustrative. Consider the HamWAN reference implementation in the Seattle area: this is a high speed (multi-megabit) IP network covering a large chunk of western Washington State, and extending north into Canada: HamWAN covers from as far north as Vancouver in British Columbia, to parts of the Cacades Range and Mount Rainier National Park, to well south of Olympia. Another segment covers most of the Portland metro area in Oregon. Virtually all of Seattle and Tacoma is covered. That is an enormous area, all covered by a high-speed, amateur operated network that is mostly independent of the Internet.

Naturally, they use AMPRNet addresses.

What do they do with it? A partial list of applications includes:

  • High-definition realtime streaming video
  • APRS igates
  • Authoritative DNS service
  • High precision network time services (a stratum-1 NTP server)

Additionally, administrative services for the Puget Sound Data Ring network are handled on the network itself. For more details see their services page.


Get an AMPRNet allocation. No seriously, please, use the resource: if we don’t make use of it, we will lose it.

Wouldn’t you like to have a ham-centric parallel Internet that you could use for amateur radio? It’s already there.