Sunday, January 24, 2010

Wondering about AMPRnet

Do you know about AMPRnet? I've wondered about this mythical network off and on since the 1980's packet boom. Back then, I was doing 1200 bps 2-meter packet from my home in Guilford, CT. I had a nice little setup with a toaster-style Macintosh, a KAM+, and a 10-20 Watt transmitter (Handytalky with an amp.). It would do the usual packet thing -- access local BBSs, digipeaters, etc. With a lot of effort, I could connect through RF gateways into New York or the Boston area. It was kind of fun sitting there and listening to each packet going out and (hopefully) returning. Not useful, by any means, but entertaining.

Then I got the TCP/IP bug. On the one hand, this was a loser for performance, adding all the overhead of full routing to each packet. On the other hand, there was a degree of error control, and I had actual IP addresses assigned to me! I was ( and ( So far as I know, the IPs are still "mine", but the server has forgotten about me. :-(

There is a "Class A" network assignment for AMPRnet or "" --, or as we now say in CIDR terms, 44/8. That's a big deal. That is an allocation of 2**24 = 16,777,216 individual IP addresses, about 1/256 of the entire IPv4 address space, assigned to Amateur Radio. That's the same IPv4 address space that is supposed to be exhausted as soon as 2011.

AMPRnet appears to be very lightly administered (and that's being polite) -- even for an amateur radio activity. The allocations are supposed to be managed by regional volunteers, but coverage seems spotty. The advertised coordinator for my area seems to be inactive now, so there is no one for me to even ask about my allocation! And, if you can get a number, it doesn't have much value, since no one can route packets to you unless you make "upstream" arrangements that are impractical for individuals. People seem to set up tunnels to a server at, which probably works, but is hardly the way to build a big network!

Traditional packet radio has been in long decline, except for special uses like APRS and DX spotting. Newer digital developments, such as DSTAR and HSMM use TCP/IP technology, since it's still the standard for computer networking, and they may use AMPRnet addresses.

What about that 44/8 network? Is there any way, other than history, to justify maintaining that huge allocation in the face of a global IPv4 number shortage? I know of no simple way to find out which ones are allocated. I would be surprised if there were as many as 1,000 in use. Out of 16 million, it's a trivial number.

The simple fact is that amateurs got a Class A allocation in 1992, when people weren't asking many questions and commercial use of the Internet was just beginning. We'd never get it today.

We should ask why amateurs actually want any IP number assignments. Wouldn't we do just as well with a non-routable private network like 10/8? The vision that somehow a random Internet user needs to interact with a random Amateur Radio station is an odd one. If it involves RF transmission, only licensed operators are allowed -- although the status of server based systems like e-mail and the web may be unclear. It's 2010, and we have 20 years of Internet and ham radio development to look back on. Ham digital nets are fragmented and don't talk to each other much, let alone the Internet as a whole. Why do we need full routability between the RF world and the Internet?

The Internet <--> ham model that is working is tunneling through the Internet to interconnect radio devices and computers. Echolink, IRLP, and DSTAR rely on this mode. No permanent addresses are required. An RF-to-Internet gateway is generally at someone's house or place of work, where there is a standard Internet Service Provider connection. The gateway relies on the ISP's assigned address, just as we all do for domestic service.

So maybe AMPRnet needs to be put to rest, giving its water back to the tribe. That would make a nice press release: Public-spirited amateur radio operators help the Internet put off catastrophe for 2 months!

Or, maybe I'm missing something important. Let me know in the comments!

Jeff, WA4ZKO, has some good comments here and here.


goody said...

I was just going to write a blog article on this topic. Last night on Slashdot I saw that we're down to 10% of the addresses left for allocation in IPv4. I was thinking about how getting back the 44. network would help and I'm surprised someone hasn't attempted to do it.

I wonder if we have an allocation in IPv6? Unfortunately it probably doesn't matter anyway as it's doubtful we'll ever create a ubiquitous and self-sustainable IP network.

Martin AA6E said...

The fact (as it seems) that there is no clear organization behind AMPRnet may be "protecting" us. There is no one who has the authority to give it back! I'm asking ARRL if they have any connection to 44/8. They seem like the obvious responsible group. (But note that Internet assignments are an international problem. Maybe an IARU issue?)

Martin AA6E said...

Jeff - all very interesting.

A little known fact is that each and every Internet user gets the entire 10/8 network (16 million addresses) to use as he or she pleases. The only problem is that it is not routable from the Internet. No problem, you can set up your own custom gateway if needed. (This used to be common in the bad old days of DECnet, UUCP, etc. that had to connect to the new IP nets somehow.)

For hams, it's a mistake to think that the 44/8 network is some kind of asset to Amateur Radio -- that it could ever be used. Most hams, I bet, don't know that Amprnet exists, but those who do probably think that it must have some value.

But it doesn't really, for all the reasons you provide. Except that there is some historical usage, and there are some announced subnets in the Internet routing tables for 44/8. (See, for example.)

73 Martin AA6E