Multicast audio for PA system

Version 1
    This document was generated from CDN thread

    Created by: YANIS SAUVE on 29-10-2012 08:56:57 AM
    Hello everyone,
    Here's my setup:  CUCM 7.1.2, SCCP phones, using a Cyberdata V3 Paging Server (SIP).
    I'm using the paging server by dialing it's DN, and then it multicasts audio to SIP Speakers for paging purposes.
    Is there a way to have the phone continually listen to the same multicast IP:port?
    I've come across RTPMRx with CiscoIPPhoneExecute.
    By using this, will the phones continue to listen for the multicast stream even if it's not used, all this without disrupting phone functionality?
    My plan would be to have a machine send the HTTP POSTs to the phones periodically to keep them listening, or is there a way I could include the relevant commands in the XML config file so they start listening each time they reboot?

    Subject: RE: Multicast audio for PA system
    Replied by: David Staudt on 29-10-2012 03:50:58 PM
    I think in general your plan should work.  See the 'Interaction with Call Streaming' section for details on how it works with normal call operation.
    Note also you can take advantage of the 'Idle URL' functionality, which will cause the phone to retrieve a URL (which you can then have trigger your streaming service) after a configurable idle period.

    Subject: RE: Multicast audio for PA system
    Replied by: YANIS SAUVE on 30-10-2012 12:01:06 PM
    I got it to work as I supposed it's intended.
    But that won't work for me, because as soon as the multicast command passes, the phone open a channel, and when there is no sound, I still hear a hiss in the speaker.  Not really what I wanted.  I would've liked the phone to stay silent, and open it's speaker only when there is something broadcasted on the multicast channel.
    Thanks a lot for the suggestion.  I hope this thread can help somebody else.