Traffic light and router: what they have in common

1. Step 1. Traffic light — has part — Relay. Relay controllers.
2. Step 2. Relay — is part of — Electrical telegraph. Relays boosted the signal on long lines.
3. Step 3. Electrical telegraph — works like — Packet switching. An analogy: telegraph messages were passed from station to station with intermediate storage — a “store and forward” principle similar to packet transmission.
4. Step 4. Packet switching — is used in — Router. It forwards packets.

Open Evothings