Source-specific multicast (SSM) support

Wowza Streaming Engine
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We run Wowza in a network that natively supports IP multicast, which means there is an increased opportunity for more than one sources to be using the same multicast group. It is therefore important to filter out unwanted sources in order to avoid the possibility of interference. We can also do this with firewall rules or filters on the host or at the edge router, but the right way to do it would involve Wowza using SSM (IGMPv3/MLDv2 include joins) for multicast input. To trigger SSM Wowza could honor both the source-filter attribute in SDP files (RFC 4570) as well as a URL scheme like the one used by VLC for MPEG-TS/UDP input: udp://source@group:port

I’m not sure however what is the state of Java support for SSM: I’ve seen the JSSM library (https://jssm.dev.java.net/) which mentions that SSM will be natively supported in Java 7.

While on the topic of multicast, I have a couple more questions:

  • Does Wowza support IPv6 multicast?

  • What happens if I give Wowza a hostname instead of a multicast group, and this hostname resolves to both IPv4 and IPv6 multicast addresses?

  • Is there any support for multicast streaming output?

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Does Wowza support IPv6 multicast?

I believe we do. It has not been explicitly test but I believe it should work.

What happens if I give Wowza a hostname instead of a multicast group, and this hostname resolves to both IPv4 and IPv6 multicast addresses?

Again, I believe this works. Give it a try.

Is there any support for multicast streaming output?

Yes there is. It is only achievable through the servers-side API (see the RTPUtils utility class - https://www.wowza.com/resources/WowzaMediaServer_ServerSideAPI.pdf). You can push out a multi-cast stream. There is currently not a way to do this using RTSP/RTP. Only native RTP.

Charlie