The video explains how main agents coordinate with sub‑agents through structured communication protocols. It begins with the initial handshake, where the main agent broadcasts a discovery packet and sub‑agents respond with capability descriptors. After negotiation, a session key is exchanged using asymmetric encryption to secure subsequent messages. The protocol defines three message types: commands, status updates, and alerts, each with a fixed header containing a sequence number, timestamp, and checksum for integrity verification. Flow control is managed by sliding‑window acknowledgments, allowing sub‑agents to request retransmission of lost packets. Priority tagging enables urgent alerts to pre‑empt regular status traffic. Error handling includes retry limits, exponential back‑off, and fallback to a secondary channel if the primary link fails. The video also covers synchronization mechanisms: sub‑agents periodically send heartbeat signals, and the main agent issues time‑sync packets to maintain a common clock. Security measures such as mutual authentication, nonce usage, and periodic key rotation are highlighted to prevent replay attacks. Finally, the protocol supports dynamic scaling; new sub‑agents can join without disrupting existing sessions, and the main agent can gracefully de‑register agents, ensuring clean resource release.