Commercial Radio Support

Hello all. I’m new to Asterisk, but from the little I’ve read it seems Asterisk doesn’t support interfacing with commercial radio directly (example: Motorola MCC 7500), besides the app_rpt Asterisk application that targets amateur radio (see It seems app_rpt is a fork of Asterisk (app_rpt and chan_usbradio removal from trunk). Am I correct in concluding that Asterisk doesn’t support interfacing with commercial radio? Just thought I’d double check here with the experts.
Thank you!

Well the interface you get with the amatur radio stuff is usually audio and a “PTT” line that plugs in to the radio running a repeater. I’ve only dealt briefly with using Asterisk on the network side of the linking.

How are you wanting to interface? What are you trying to accomplish exactly?

Thanks for the quick response. After a little more reflecting I think we can do what we need if the ‘Motorola MCC 7500’ is included on our Asterisk network, and it looks like it actually is possible. According to ‘’, it is stated ‘The Session Initiation Protocol (SIP) is used to communicate with the media gateways across the console IP network’. So it’s likely that this commercial radio product is also able to register with Asterisk. Thanks!

Not sure if this is any off a help, but look into Asterisk JACK and JACK_HOOK

Digging into this deeper, it seems that having PTT (Push To Talk) embedded in the RTP message header might go a long way in supporting radio. Details are covered in section ‘ RTP header extension’ of ‘Voice communication system for air traffic control’ ( Is there a way to modify the RTP header to embed PTT on/off information? The PTT on/off information would need to be detected by a program that monitors a PTT input.

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