Chapter 1, Problem P10P

Explanation of Solution

The formula for calculating the link rate to transmit the required packet is $\frac{\text{Length}\text{of}\text{the}\text{packet}}{\text{Transmission}\text{rate}\text{of}\text{the}\text{link}}\text{=}\frac{\text{L}}{{\text{R}}_{\text{i}}}$

The rate of first link required to transmit the packet at first end system is $\frac{\text{L}}{{\text{R}}_{\text{1}}}$  and similarly for second and third links $\frac{\text{L}}{{\text{R}}_{\text{2}}}$ and $\frac{\text{L}}{{\text{R}}_{\text{3}}}$

The formula for calculating the propagation speed of the packet over the link is $\frac{\text{Length}\text{of}\text{the}\text{link}}{\text{Propagation}\text{speed}\text{of}\text{the}\text{link}}=\frac{{\text{d}}_{\text{i}}}{{\text{s}}_{\text{i}}}$

The propagation speed of the packet over the first link is $\frac{{\text{d}}_{\text{1}}}{{\text{s}}_{\text{1}}}$ and similarly for second and third links $\frac{{\text{d}}_{\text{2}}}{{\text{s}}_{\text{2}}}$ and $\frac{{\text{d}}_{\text{3}}}{{\text{s}}_{\text{3}}}$

The processing delay of the packet at each switch is ${\text{d}}_{\text{proc}}$

The end-to-end delay of the packets can be calculated by using the below expression