AEQ
PHOENIX MERCURY
16
b) Multicast:
it is also possible to send the audio stream to a special “multicast” address, for
example, 239.255.20.8. If the receiving equipments call to that same IP, they will receive the
audio that is being sent provided that their “local media port” matches the one the transmitter is
sending the packets to. Similarly to broadcast, multicast traffic is usually blocked by switches
and routers, so its use is restricted to local area networks too.
c) Multiple-unicast:
Phoenix units can send the same RTP stream to several different IPs by
replication of the encoded audio. This can traverse switches and routers in the same way it
would do if it was a simple (unicast) RTP Raw stream, although it is limited to a certain number
of destination IPs depending on the type of coding algorithm.
You can access “
Multiple-unicast
” configuration by means of the corresponding button within
the IP interface configuration screen Net1 (or Net2).
Once we have properly configured a RTP Raw channel, we can add replicas or parallel
streams, which are only IP+port pairs we want to send the audio to. Note that FEC can be
individually activated provided that it was enabled (and configured) in the general channel
configuration (see section 3.4) or it can also be disabled for certain replicas if you want. If the
list is empty, the stream will be normally sent to the IP+port indicated in the Call window, as
usual.
NOTE:
When audio is sent to several destinations, the transmitting unit can receive audio from
only one of them (or none). In order to determine which one is sending audio back, only in RTP
Raw mode, a control will appear in the general configuration window next to the ENCODER
output allowing us to disable the transmission to the IP channel. Make sure that only one of the
receiving equipments is enabled to transmit:
Channel transmission activated
Channel transmission inhibited
NOTE: Please read the application notes published by AEQ regarding IP connectivity for
more information on IP communications in particular scenarios.