##
Performance Metrics
The numbers that describe a healthy link — and why bandwidth is only part of the story.
| Bandwidth | Max theoretical capacity (bps) |
| Throughput | Actual data rate achieved |
| Goodput | Useful app data (minus overhead) |
| Latency | One-way / round-trip delay (ms) |
| Jitter | Variation in latency — hurts voice |
| Packet loss | Percentage of packets dropped |
| MTU | Largest frame without fragmenting (1500) |
// application targets
| Traffic | Latency | Jitter | Loss |
|---|
| Voice (VoIP) | < 150 ms | < 30 ms | < 1% |
| Video conferencing | < 200 ms | < 30 ms | < 0.1% |
| Interactive / SSH | < 100 ms | — | low |
| Bulk / file transfer | tolerant | — | tolerant |
// rules of thumb
- Voice target: < 150 ms latency, < 30 ms jitter, < 1% loss
- Bandwidth ≠ throughput — overhead & congestion reduce it
- 8 bits = 1 byte → watch Mbps vs MB/s
- Bandwidth-delay product = how much data fills the pipe