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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>As far as I am aware there isn’t a way for * to
receive/send audio to a multicast group. There needs to be a way
for Asterisk to tell the phone which ip multicast group to join in order to
receive the page. This method varies by vendor. I know that
with Cisco ip phone multicast paging they send a SCCP message to the phone to
instruct it to send the appropriate IGMP join for the multicast group. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Another way would be to advertise the ip multicast groups
with SDP. Do you know how the Zultys phone knows which ip multicast
group to join? <font color=navy><span style='color:navy'> I hope
they aren’t statically tying themselves to 224.0.0.1 as this is a
reserved ip multicast address always has a TTL of 1. </span></font> <font
color=navy><span style='color:navy'>If they are using this address have them
read RFC 1112. </span></font><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>>>>The reason? I have found a method to paging on
Zultys ZIP2 and ZIP4x4 handsets. Basically it involves sending a stream of RTP
data to port 3771 to multicast address 224.0.0.1.<o:p></o:p></span></font></p>
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12.0pt'><o:p> </o:p></span></font></p>
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