Send a TV channel to multicast¶

In hospitality and operator IPTV networks, it is common to deliver TV channels inside a local network via UDP multicast (usually MPEG-TS).

Catena SE can “push” (publish) a TV channel to a multicast group — this is typically done for compatibility with TVs/set-top boxes that expect IPTV over UDP.

Prerequisites¶

• The network must correctly support multicast (IGMP/IGMP snooping, routing between VLANs if needed).
• Catena SE nodes must send multicast traffic via the interface connected to the local network (not the internet uplink).

Basic setup¶

Multicast output is configured on the channel itself, in the Push section.

This setting is not available in templates, because it does not make sense there: push defines “where and how to deliver this specific channel” (a concrete multicast group/port), not a content processing rule.

Open the Push tab.

To send a channel to UDP multicast, add a push to the required address.

Typical format:

udp://239.0.0.1:5000

Where:

• 239.0.0.1 is the multicast group IP;
• 5000 is the UDP port.

“One port for all channels” (AMAKS-style)¶

A common design is to use the same port for all channels (for example, 5000) and vary only the multicast IP:

• udp://239.0.10.1:5000 — Channel 1
• udp://239.0.10.2:5000 — Channel 2
• udp://239.0.10.3:5000 — Channel 3

This simplifies operations (ACL/firewalls/players) and makes addressing easier to explain.

Advanced options (if needed)¶

Below are a few options that are often useful in IPTV networks.

Track selection¶

If a channel has multiple tracks, you can explicitly choose what to send:

udp://239.0.0.1:5000?tracks=v1a1

Where:

• v1 is the first video track;
• a1 is the first audio track.

Choosing a network interface¶

If you need to explicitly choose the interface for multicast egress, you can use the interface-name form:

udp://eth0@239.0.0.1:5000

Where eth0 is the interface connected to the local IPTV network.

PID configuration¶

If needed, you can configure the PIDs of the outgoing MPEG-TS stream (PMT/PNR and track PIDs).

This is useful when your TVs/STBs/headend expect specific signaling or fixed PID values.

Bonus: CBR UDP stream preparation¶

When pushing to UDP, Catena SE can also prepare a CBR (constant bitrate) UDP stream, which is useful for some IPTV networks and equipment.

Authorization limitations¶

Important: protection (token-based authorization) does not work for UDP multicast.

UDP multicast is not a client-server protocol: the server does not see individual clients and therefore cannot validate viewer tokens.

If you need access protection inside the network, typical approaches are:

• network isolation/VLAN/ACL;
• CAS/encryption in the IPTV layer (depending on your design).

MPTS and advanced multiplexers¶

Building multiple channels into MPTS and advanced multiplexer settings (SI/NIT/SDT, LCN, “multiplexer”) are available in the separate MCaster product.

Verification¶

You can verify multicast delivery on any host in the same network (or on a TV/STB).

Examples:

• in VLC: open a network stream udp://@239.0.0.1:5000
• in ffplay: ffplay udp://@239.0.0.1:5000

If playback does not start, the root cause is most often the network (IGMP/routing/ACL) rather than Catena SE.