EchoLink, AllStar and IRLP: repeaters over the internet
A repeater covers a region. Link one to another over the internet and a five-watt handheld reaches whatever the far end covers. All three of the common systems carry ordinary analogue audio — the digital part is the transport, not the radio.
EchoLink
The most accessible of the three, because you do not need a radio at all: a validated licence lets you connect from a phone or computer directly into a node. Each node has a number, and you connect by sending that number as DTMF tones from your radio, or by picking it in the app.
Validation requires proof of licence, which is why EchoLink is a common first step for a newly licensed operator with no antenna yet.
AllStar
Built on Asterisk, the open-source telephone exchange, which tells you most of what you need to know: it is flexible, it is configured rather than bought, and it is popular with people who enjoy that. Nodes have numbers and can be linked and unlinked on the fly, permanently or for one conversation.
IRLP
The oldest, and the strictest: IRLP links radio to radio only, with no computer-only access by design. That restriction is the point — everyone on an IRLP link is a licensed operator on the air, which some communities value enough to accept the smaller network.
Etiquette on a linked system
- Leave a longer gap between overs than you would locally. Links add delay, and someone at the far end is waiting for a chance to speak.
- Say where you are. The other station may be on another continent and has no idea.
- Do not leave a link connected when you have finished with it.