Transmission and propagation delay

Question

I have a very simple calculation for the delay over a simple link and i do not understand a part in the solution.

Consider that:

I have a 10Mbps line, 200.000.000 m/s cable speed, 2.000 km distance, and 8.000 bytes file.

The solution is this:

---

I do not understand why an extra '8' is added in 'L' and an extra '10' is added in 'C'. Can someone please explain it to me?

I searched it on Google and i could not find an answer, although i assume that this is something basic (maybe i don't know how to search properly :p)

Thanks in advance.

Answer 1

Simple maths i guess

• 1 Byte = 8 bits ; so you have 8
• 8 * 1000 = 8000 ; you have another 8
• 10 Mbps = Ten Mega bits per second
• Mega = 1,000,000 ; you have 10 in front

So in conclusion

• 8.8.10^3 == 8000 bytes
• 10.10^6 == 10Mbps

Hope I helped you with MATH ;)