TCP/IP over Packet Radio
Packet radio is, however, only a point-to-point medium. In order to build a network with stations able to communicate anywhere whether in direct contact or not, more layers of mechanisms are required.
The TCP/IP protocols, first developed from research into reliable military communications, have proven themselves to be robust and efficient. As their use in today's Internet proves, they can be effective nearly anywhere.
The people of the amateur radio community who are experimenting with advanced communications methods have decided to use these same protocols in amateur radio digital communications.
Not only does this capitalize on the many advantages of TCP/IP itself, but also serves to promote enhancements to the protocols arising from unique problems seen in transmitting them over radio links.
A number of recent improvements to TCP/IP were first discovered by amateurs working on achieving reliable efficient data transmission over lossy and congested radio paths.
AMPRNet ( Amateur Packet Radio Network )
IPv4 Network 44/8 is known as the AMPRNet, named from "AMateur Packet Radio Network".
Volunteer hobbyist amateur radio operators are investigating the construction of an entirely radio-based world-wide network using TCP/IP.
Network 44, termed the AMPRNet, is that network.
An address allocation originally obtained in the 1970's by Hank Magnuski, today it is administered as a distributed disjoint group of subnets by regional "coordinators", who assign addresses on the network to amateur radio operators in their area.
The worldwide overall organization of these subnetwork blocks is current handled by Brian Kantor.
Addresses on this network are available to any licensed amateur radio operator who is interested in advancing the art of amateur radio digital communications.
Internet connectivity and the management and behaviour of the connected host system is the responsibility of the person who owns that computer.
Amateurs are in an unusual situation compared to the rest of the Internet. We're trying to build our own radio-based network, so for the goals of the network, radio connectivity is more important than internet connectivity. The current structure of the AMPRNet is that there are a bunch of fully and partially-isolated ("disjoint") subnets in nearly every country and most major cities around the world.
Some of these have radio links to adjacent subnets but no other connections, some of them are completely isolated, and some are connected to others via "tunnels" through the Internet. This is a network in growth, and the status of subnets changes daily.
There is a single low-bandwidth tunnelling router located at UCSD and managed by Brian Kantor, which allows a minimal connectivity between the main Internet and some parts of the AMPRNet. It is there primarily to allow experimenters on the AMPRNet the opportunity to exchange information and to obtain access to Internet resources.
AMPRNet is not intended to be, and should not be used as, a substitute for buying access to the Internet from a local Internet Service Provider.
It is, at this point in its evolution, an experimental network which should not be relied upon to provide consistent or dependable communications. As with amateur radio itself, it is a hobbyist adventure.
AMPR.ORG is the domain that is available for amateur radio operators to register their AMPRnet hosts, and for other amateur radio related computer systems.
Domain names in AMPR.ORG are available to any licensed amateur radio operator who is interested in advancing the art of amateur radio digital communications.
In most countries, there is a local coordinator who is responsible for assigning an address and updating the master hosts list.
There is no formal organization, no membership requirements, and no dues. All of the work is done by volunteers as they have time to do it.
If you are an amateur radio who needs an address, contact your national/local coordinator.
AMPR.ORG is not intended to be, and should not be used as, a substitute for buying a personal domain name. It's really there for amateur radio use.
AMPRNet and Internet
The AMPRNet is mostly NOT connected to the Internet. Out of the multiple thousand computer systems (hosts) registered in the AMPR.ORG domain, and the thousands of IP addresses on network 44, few are actually able to reach or be reached from the Internet.
In addition, these are amateur radio stations. In nearly every country in the world where amateur radio is permitted, there are very tight restrictions on the content of messages that may be transmitted. Willfully violating these restrictions could result in government fines and/or the forfeiture of the amateur radio license and quite possibly the radio equipment as well. That means that most amateurs are far more careful about what content leaves their equipment, even if it's not over the radio, than the ordinary Internet user would be.
To check the host is connnected to internet or not, you can use the usual internet tools - traceroute (tracert on some systems), ping, dig, nslookup, smtp VRFY, etc., to discover whether the given host exists or not, and whether it is routed to or not (most aren't!).
Look at the hostname given. Most AMPR hostnames have the amateur radio callsign in front of the .ampr.org part.
In ALL countries that allow amateur radio, the callsign and who it belongs to and where he is located is public information. Most countries have Amateur Radio callbook containing this data that are used by amateurs to exchange written confirmations of signal reports and other experiments.