sequenceDiagram
  participant S as Sender
  participant R1 as Receiver 1
  participant R2 as Receiver N
  S->>R1: Unicast handshake PIN codec tier
  S->>R2: Unicast handshake
  Note over S: One encoder one sessionId
  S-->>R1: Multicast media packets
  S-->>R2: Same packets
