What is an Allstar Link network?
The AllStar Link network consists of a number of large (and small) individuals and groups who wish to provide efficient large-area communications to the Amateur Radio public in their respective local areas.
This is done by providing a local VHF or UHF repeater system controlled by a Linux-based computer system running the open-source Asterisk PBX telephone switch platform along with the app_rpt repeater/remote base controller/linking software module (which is included in the distribution of Asterisk) connected to a high speed (broadband, such as Cable Modem or DSL) Internet connection.
You can read up more from Allstar Link's website
Nodes, nodes, nodes!
I happen to have several personal nodes running the HamVoip Asterisk software on Raspberry Pi 3 B, that are connected to the WinSystem and one acting as an Echolink node. One node is a Yellow Box Node which I bought from George - WB3DZZ and the others ones I custom built.