We have been using Wowza 3.5.4 without problems. We recently updated to version 4.1.1 Wowza Streaming Engine build13180 and are experiencing a problem with multicast.

We are using VLC as media player and the MRL is "rtsp://argos.hcdn.gob.ar/live/evento-2.stream?multicastplay". In version 3.5.4 we could connect to the multicast stream with the parameter ?multicastplay, but in the new version we are connecting to a unicast stream. We can certify this because we observe the unicast connection in the log, in the Server Monitor and also we can see unicast traffic with Wireshark. However, if we double click on the SDP file a multicast connection is initiated. Further, if we modify the parameter ?multicastplay for ?what3v3r, there is no error, the unicast connection takes place.

This is our "C:\Program Files (x86)\Wowza Media Systems\Wowza Streaming Engine 4.1.1\conf\PushPublishMap.txt":

evento-2.stream={profile:"rtp", streamName:"evento-2.stream", host:"", videoPort:10020, audioPort:10022}

And this is our "C:\Program Files (x86)\Wowza Media Systems\Wowza Streaming Engine 4.1.1\applications\live\sdp\evento-2.stream_evento-2.stream.sdp"

o=- 1316670289 1316670289 IN IP4
t=0 0
m=audio 10022 RTP/AVP 96
c=IN IP4
a=rtpmap:96 mpeg4-generic/48000/2
a=fmtp:96 profile-level-id=1;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3;config=1190
m=video 10020 RTP/AVP 97
c=IN IP4
a=rtpmap:97 H264/90000
a=fmtp:97 packetization-mode=1;profile-level-id=4D0029;sprop-parameter-sets=Z01AKZZSAKALdgKhAAADAAEAAAMAMuCgAD0JAABAFn8Y4wUAAehIAAIAs/jHDtCxaJA=,aOtzUg==
a=framesize:97 1280-720

Also found another problem: Our server has two NIC. When we try to associate the multicast to one of the NIC address via GUI, we find that it is not possible to change the value: multicastInterfaceAddress_out. It's remain 0.

<!-- <MulticastBindToAddress>true</MulticastBindToAddress> -->
<!-- <MulticastInterfaceAddress></MulticastInterfaceAddress> -->
<!-- <TrafficClass>0</TrafficClass> -->