demo · v142

Multicast receiver

Pick a multicast group, watch the simulated network: one sender, several receivers — those that joined the group light up and receive each packet, the others ignore it. Try the real UDPSocket constructor with the button; it will only succeed inside an Isolated Web App.

IWA-only UDPSocket and Direct Sockets are exposed only inside Isolated Web Apps. To run the real API, install the IWA from chrome://web-app-internals and reload there. This page simulates the multicast dataflow for everyone else.
valid multicast group?
—
group scope
—

relevant API

// Isolated Web App only
const socket = new UDPSocket({
  localAddress: "0.0.0.0", localPort: 5353,
  multicast: { groupAddresses: ["224.0.0.251"], loopback: true },
});
const { readable } = await socket.opened;
for await (const { data, remoteAddress } of readable) { /* … */ }

see also