Broadcast to multiple phones

Unanswered Question
Feb 27th, 2007

I've tried out the sample for hootie and intercom and one-way communication from 1 phone to another is working fine.

However, I'm having problem trying to broadcast to multiple phones. Has anyone tried this? Greatly appreciate any pointers given.

Thanks in advance!

I have this problem too.
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XmlEquals Tue, 02/27/2007 - 09:36

I see you are on the right path from your other post.

Send RTPMTx to a host phone, and RTPMRx to any phone that should be able to hear the media coming from the RTPMTx'ed phone, and you should have an app...

leowong Tue, 02/27/2007 - 10:07

As XmlEquals mentioned, send a RTPMRx to a group of phones. Make sure the IP is a multicast one and the port is of even number.

oonchenph Tue, 02/27/2007 - 18:31

thanks for the tip, starting to see some lights... however, i'm still lost about how to RTPMTx to multiple phones. Is it something like making use of push2phone function to a group of phones?

leowong Tue, 02/27/2007 - 18:40

basically, it involve sending the RTPMRx XML to multiple phones, requesting them to join the same Multicast address/port.

XmlEquals Tue, 02/27/2007 - 23:35

oonchenph, basically, for a given broadcast session or instance, you don't send RTPMTx to multiple phones--only one phone get's that command, as it's the host to the other phones (who will be sent RTPMRx)

leowong Tue, 02/27/2007 - 23:43

I re-phase, the RTPMRx has to be sent to multiple phone ONE BY ONE.

oonchenph Tue, 02/27/2007 - 23:44

Let's see whether I get the concept correct. To do a PA (Public Announcement), speaker will talk on Phone A and it will transmite the message to Phone B, C, D and so on.

I'll send a RTPMTx:Phone A IP:Port1 to Phone A which is the host phone. Then, I will also send RTPMRx:Phone A IP:Port 1 to Phone B, C, D and so on which supposed to receive the broadcast. Correct?

stephan.steiner Wed, 02/28/2007 - 01:31

>I'll send a RTPMTx:Phone A IP:Port1 to Phone A which is the host phone.


RTPMRx and RTPMTx are multicast commands... so class D network addresses, an address your phone never has (if you don't know the difference between unicast and multicast, do a google search on the terms.. the distinction is important and one of the basics of networking).

So here's an example of what you'd send to phone A:


And here's what you send to all the phones that need to receive your broadcast:


Then speak to your network administrator and ask him if your network supports multicast. If you have all your phones in the same network segment (single office scenario), that's no problem, but if your phones are in different subnets, then the router needs to be configured to support multicast (by default, routers don't route multicast). If your network admin doesn't know what to do, you're on the proper site already.. just search the cisco site for multicast configuration (I'm not a network guy so I'd have to look it up, too).

oonchenph Wed, 02/28/2007 - 01:48

many thanks, i think i get a clearer picture and better understanding on this multicasting now.

Will check and try it out! Thanks for all the tips... :)


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