This page features extracts from the official AllStarLink website:  https://www.allstarlink.org/

AllStarLink is a network of Amateur Radio repeaters, remote base stations and hot spots accessible to each other via Voice over Internet Protocol. AllStarLink runs on a dedicated computer (including the Rasperry Pi) that you host at your home, radio site or computer center. It is based on the open source Asterisk PBX running our app_rpt application. App_rpt makes Asterisk a powerful system capable of controlling one or more radios. It provides linking of these radio “nodes” to other systems of similar construction anywhere in the world via VoIP. (Voice over Internet Protocol)

AllStarLink’s primary use is as a dedicated computer node wired to your repeater or radio. Connections from Echolink, other VoIP clients and telephone calls are supported.

AllStarLink has the unique characteristic that repeaters and remote base nodes are completely separate from each other.  That means that just because a remote-base is at the same site or even on the same computer system as a repeater, they are not tied together in any way. They are implemented as completely separate nodes, usable separately.

The AllStarLink website has ‘Live Node Count’ page which constantly refreshes the total number of nodes presently available.   https://www.allstarlink.org/starwars.php

There is also a node search tool that allows the details of each node to be examined in detail.

https://www.allstarlink.org/nodelist/

Unlike other Radio-centric VOIP technologies, such as Echolink or IRLP, etc, AllStarLink and the app_rpt/Asterisk technology have been specifically designed to be part of the infrastructure of the radio systems that it implements, as opposed to be an end-to-end protocol like others.

AllStarLink is an attempt to take this technology and make it available and applicable to as many Amateur Radio operators as possible, via their local repeater systems.

An AllStarLink manual describes the process of setting up a node in great detail:  

https://allstarlink.github.io/#

The Tech Minds You Tube channel has produced an excellent video describing AllStarLink