No new content. Today you collect real numbers: how long a ping takes to cross the country and the ocean, how many hops it makes, and how fast you are at speedup arithmetic.
No reading — measure. Keep 6.8 (latency) and 6.10 (speedup) open. Your teacher hands out the Lab 6.12 sheet with the speedup scenarios.
Internet, measured. Every claim in this lab is backed by a number you produced — the course’s rule since Unit 4.
1. Latency. ping a server on at least three continents. Record the round-trip time in milliseconds.
2. Hops. traceroute (or tracert on Windows) to the same servers. Count the hops.
3. Bandwidth. Run a speed test once. Record download and upload in Mbps.
4. Chart. Latency (y) vs. distance (x). One sentence explaining the pattern.
5. Speedup. Five correct speedup calculations from the lab sheet.
Light in fiber travels about 200,000 km per second — two-thirds of its speed in a vacuum. A ping goes there and back, so the fastest possible round trip is 2 × distance ÷ 200,000 km/s. Pick a destination, then enter what you measured.
Your measured times will be higher than the floor. Cables don’t run in straight lines, and every hop adds a little delay. If your chart still rises with distance, that’s physics showing through. (Distances are straight-line distances from Irvine, rounded.)
Fresh problems every time. Get five right in a row and the arithmetic is automatic. Answers to two decimal places.
| Turn in | What it must show |
|---|---|
| Data table | Destination, distance, ping (ms), hops. Three continents minimum. |
| Chart | Distance on x, latency on y, both labeled with units, y-axis from zero. |
| One sentence | The pattern, and one reason the measurement is above the speed-of-light floor. Say only what your data shows. |
| Speedup | Five calculations from the lab sheet, with the work shown. |
Four questions on reading measurements.