Listen to radio dispatch traffic on IP phones

Unanswered Question
Apr 8th, 2009

Customer has a request to allow IP phone users (possibly dozens)to listen to live radio dispatch at any time. Only connection from the dispatch system is an analog output. E&M port to FXS port? Multicasting?


I have this problem too.
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Overall Rating: 3.7 (4 ratings)
testeven Wed, 04/08/2009 - 09:40


Using a soundcard in the CUCM server you could set up a Music On Hold server which plays a radio stream to callers while on hold.

You would need to connect a radio using a standard audio cable to the soundcard which will then be able to stream the music into your network.

But if you are looking to listen to the readio at any time from the IP phone speaker, this is not possible.

HTH, if it does, please rate.



CHRIS CHARLEBOIS Wed, 04/08/2009 - 13:04

I think 'impossible' is a little strong in this case. I seem to remember some options within the IP Phone Services SDK about receiving multicast audio to the speaker through a Phone Service, although that would require quite a bit of development. It is possible that this might be an option through Berbee's Informacast or IpCelerate's IpServer products.

dwarner3500 Mon, 04/13/2009 - 07:42

I am in contact with the customer about whether they think it worthwhile to look in the IPICS direction. Thanks for yourr input...

James Hawkins Mon, 04/13/2009 - 02:16

Multicasting should be the way to go. The config below takes an audio stream from an E&M port and converts it to an IP multicast.

voice-port 1/0/0

connection trunk 111

music-threshold -30

operation 4-wire


dial-peer voice 1 voip

destination-pattern 111

voice-class permanent 1

session protocol multicast

session target ipv4:

ip precedence 5

To connect to the audio multicast stream you should be able to write a basic IP service using the RTPMRx URI

Multicast Streams

Choose an option

Stream One


Useful links:

Please rate if helpful

dwarner3500 Mon, 04/13/2009 - 07:41

Thanks for your info. It was very helpful. I now have a few ways to approach this scenario. I was also in contact with SingleWire (Berbee) about possible solutions and might have a way to go with an external USB MOH adapter and a phone service. SingleWire doesn't support it but they know it works.

Again thanks for your input.

dwarner3500 Fri, 05/08/2009 - 10:57

Hi Jamesha,

I wanted to ask if there was anything important in the 'voice class permanent' config. You didn't add that to your example....


dwarner3500 Fri, 05/08/2009 - 11:18

Got it, thanks. I'm going to study the doc in depth. I see the voice class commands, might as well put it in there. Does the virtual interface (vif1)need a specific IP address or just on a different subnet?


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