Internet Radio Linking Project

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Internet Radio Linking Project" – news · newspapers · books · scholar · JSTOR (March 2008) (Learn how and when to remove this message)

The Internet Radio Linking Project, also called IRLP links amateur radio stations around the world by using Voice over IP (VoIP). Each gateway consists of a dedicated computer running custom software that is connected to both a radio and the Internet. This arrangement forms what is known as an IRLP Node. Since all end users communicate using a radio as opposed to using a computer directly, IRLP has adopted the motto "Keeping the Radio in Amateur Radio".

Amateur radio operators (hams) within radio range of a local node are able to use DTMF tone generators to initiate a node-to-node connection with any other available node in the world. Each node has a unique 4 digit node number in the range of 1000–8999. A real-time searchable list of all nodes worldwide (including their current status) is available anytime by viewing the IRLP Network at a Glance. As of February 2019, there are over 1,500 active nodes.^[1]

IRLP connections are of two types: node to node, and node to reflector. Stations wishing to communicate with 3 or more nodes at the same time may accomplish this by connecting to what is called an IRLP Reflector. Reflectors are a type of conferencing system. Most reflectors on the network have 10 channels (0–9) with channel 0 being the main channel. Each reflector has a unique 4 digit node number in the range of 9000–9999. The first 3 digits consist of the reflector number, while the fourth digit represents the channel number. As of April 2007, there are 20 operational reflectors (including Echo Reflector 9990, which digitally records and plays back transmissions for testing purposes). Since most reflectors have 10 channels, there are approximately 200 unique reflector channels available for use.