Chapter 1, Problem P27P

a.

Explanation of Solution

The formula used for calculating the bandwidth-delay product is $\text{R}\text{×}{\text{d}}_{\text{prop}}$

The expression used for calculating the propagation delay in terms of meters (m) and seconds (s) is ${\text{d}}_{\text{prop}}\text{=}\frac{\text{m}}{\text{s}}$  seconds.

Substitute, “20,000” for “m” and “2.5 ×10⁸” for “s”

The propagation delay of the link is $\frac{\text{20000}\text{×}{\text{10}}^{\text{3}}}{\text{2}}$

b.

Explanation of Solution

The size of the file transmitted from Host A to Host B is 800,000 bits...

c.

Explanation of Solution

The formula used for calculating the width of a bit present on the link is as follows

$\text{Width}\text{of}\text{the}\text{bit}\text{=}\frac{\text{Length}\text{of}\text{thelink}}{\text{bandwidth-delay}\text{product}}$

The formula used for calculating the bandwidth-delay product is $\text{R}\text{×}{\text{d}}_{\text{prop}}$

The expression used for calculating the propagation delay in terms of meters (m) and seconds (s) is ${\text{d}}_{\text{prop}}\text{=}\frac{\text{m}}{\text{s}}$  seconds.

Substitute, “20,000” for “m” and “2.5 ×10⁸” for “s”

The propagation delay of the link is $\frac{\text{20000}\text{×}{\text{10}}^{\text{3}}}{\text{2}\text{.5}\text{×}{\text{10}}^{\text{8}}}\text{=}0$