[Asterisk-Users] RTP Stream on Multicast

[Keith O'Brien]

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.  

 

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?   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.     If they are using this
address have them read RFC 1112.   

 

 

 

>>>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.

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20050217/4c05aec4/attachment.htm