P$2.$ Equation $1\mathrm{.}1$ gives a formula for the end$-$to$-$end delay of sending one packet of length $L$ over $N$ links of transmission rate $R.$ Generalize this formula for sending $P$ such packets back$-$toback over the $N$ links.

P$3.$ Consider an application that transmits data at a steady rate $($for example, the sender