I've been playing with VOIP Linking over the years with programs like ILink, EQSO, IRLP, and Echolink. I tried Allstar many years ago, but was discouraged due to my lack of Linux knowledge and that there was not much documentation on the web. Well things have changed and I now really appreciate what others have shared.
Allstar is now by far my favorite..
The Allstar web site to get started is: https://allstarlink.org. On that site you will find much information as well as the ability to register with Allstar. Once registered, you can request server and node authorization.
AM CURRENTLY USING Raspberry Pi3's FOR MY NODES.
Utilizing the software package from HAMVOIP
The Node interface is the URI from DMK Engineering
AllstarLink provides hams with a means of connecting radios (repeaters or simplex links) over the internet. It is built upon the asterisk open source PBX (runs on Linux). Audio quality is better than EchoLink or IRLP.
W2YMM ALLSTAR LINK
HELPFUL SITE TO HELP YOU GET UP AND RUNNING WITH ALLSTAR