6.4. Performance Issues

💡 First Principle: Performance problems differ from connectivity—the network works, just slowly. Causes include bandwidth saturation, latency, jitter, packet loss, and resource exhaustion. Baselines establish "normal" so you recognize degradation.

What breaks when performance degrades: Video calls freeze and stutter (jitter), file transfers take forever (bandwidth saturation), VoIP calls echo or cut out (latency and packet loss). Users experience these as "the network is slow" but each has different root causes. Without understanding performance metrics, you chase the wrong problem—adding bandwidth when the real issue is jitter from a congested router queue.

Think of performance troubleshooting like diagnosing why a car is slow: it could be the engine, transmission, tires, or even just driving with the parking brake on. Measuring the right metrics points you to the actual problem.