Connect multiple tabs/browsers to the same channel and watch messages fan out. Single tab? You still receive your own publishes back (pub/sub semantics).
disconnected
URL: (set on connect)
Each send embeds a performance.now() timestamp in the payload; the RTT is
computed when the echo returns. Under packet loss, individual datagrams drop but
others still arrive on time — no head-of-line blocking.
Each send opens a fresh stream, writes the message, half-closes, reads the full echo. Under packet loss, QUIC retransmits silently — RTT spikes rather than messages dropping.