From "PTTLink Wiki"
Allstar/app_rpt is a complete repeater (or simplex node) controller with VoIP linking and more features that most repeater controllers.
- Asterisk/app_rpt can run on many single board computers including the Raspberry Pi or as a Virtual Machine in a data center.
- Multiple repeaters (nodes) may be interfaced at one site while only running one instance of Asterisk/app_rpt on one computer.
- Ad-hoc connectivity. Any node can connect with any other node.
- Any number of nodes can connect to a node (subject to bandwidth limitations) forming a hub.
- Voting and simulcast over IP networks with Allstar Radio Thin Client Module (RTCM).
- All of the security features in Asterisk are at your disposal (Public/Private keys, IP address filtering)
- No central authority for authorizing connections. You are free to use our PTTLink, or set up a your own completely isolated network of systems.
- Registration-based authentication method forPTTLink nodes to handle Internet connections with dynamic IP addresses
- The ability to remotely execute a DTMF command on any node from any other node.
- Multiple hardware interfaces supported including the Quad Radio PCI card (EOL), the CM1x (USB), WM5102 (RPi), TLV320 (RPi) and RTCM.
- MDC-1200 support and integration
- Audio Filters - Optional filters for making the audio wider on both the lower and upper frequency limit.
- Autopatch, and Reverse Autopatch over traditional landlines or through a VoIP service provider. VOX-based or full duplex.
- VHF/UHF remote base operation using the TM-271A, Kenwood TMG-707A, Motorola Syntor X and others.
- HF remote base operation using the Yeasu FT-897 or ICOM IC-706 all-mode radios.
- Secure remote base access using individual user logins to prevent unauthorized access.
- Interoperability with Echolink, DMR and D-Star also possible.
- Control and access to the radio via telephone dialup.
- SIP and/or IAX for soft phone access to nodes.
- iaxRPT soft dispatch console for Windows. Android IAXRPT for Android phones and tablets.
- Facilities to integrate with existing addressable full duplex RF linked systems.