a$.$ Consider Figure Q$\mathrm{.}4$a$.$ A sender begins sending packetized audio periodically at $t=1.$ The first packet arrives at the receiver at $t=6.$

a$)$ What are the delays $($from sender to receiver, ignoring any playout delays$)$ of packets $1$ through $8?$ Note that each vertical and horizontal line segment in the figure has a length of $1,2,$ or $3$ time units.

$[2$ marks$]$

b$)$ If audio playout begins at $t=5,$ which of the first eight packet sent will not arrive in time for playout?

$[2$ marks$]$

c$)$ If audio playout begins at $t=6,$ which of the first eight packets sent will not arrive in time for playout?

$[2$ marks$]$

d$)$ If audio playout begins at $t=7,$ which of the first eight packets sent will not arrive in time for playout?

$[1$ marks$]$

e$)$ What is the minimum playout delay at the receiver that results in all of the first eight packets arriving in time for their playout?

$[1$ marks$]$

Figure Q$\mathrm{.}4$a

b$.$ How do you implement the token bucket policer such that we can limit the input traffic to specified burst size and average rate?

marks$]$

c$.$ In this problem we consider the delay introduced by the TCP slow$-$start phase. Consider a client and a Web server directly connected by one link of rate $R.$ Suppose the client wants to retrieve an object whose size is exactly equal to $14S,$ where $S$ is the maximum segment size $($MSS$).$ Denote the round$-$trip time between client and server as RTT $($assume to be constant$).$ Ignoring protocol headers, determine the time to retrieve the object $($excluding TCP connection establishment$)$ when $6\frac{S}{R}>\frac{S}{R}+RTT>2\frac{S}{R}.$

marks$]$