I make Radio over Internet Protocol kits for sites for my current employer. There are fifty sites spread across the United States that wish to be connected to a central dispatch location. For Motorola ASTRO based sites, this is done through a Conventional Channel Gate Way (CCGW) device. For Trbo sites, this is done through Zetron IP interface. CCGW's have eight connections, while Zetron interfaces only have a max of two links each. Radio audio is converted to IP data, and then processed by ASTRO dispatch consoles for distant sites via CCGW or Zetron 6300 series IP interface devices.
Shown is a Motorola XPR4550 UHF mobile, powered by an Astron power supply, and connected via its accessory connector to the Zetron 6300 IP interface for Push to Talk and TX/RX audio. I use this setup to test connections on my own flat network before sending hardware across the country. This is a somewhat expensive method of connecting radio to the Internet, as the mobile is often $500/1000/5000 (Trbo XPR4550/Trbo XPR5550e/APX4500), $2700 for the Zetron IP interface and $120 for the Astron power supply. Then there are the ancillary items, like the antenna and mount, coax, network hardware and jacks, and Internet connection.