P6. This elementary problem begins to explore propagation delay and transmis-
sion delay, two central concepts in data networking. Consider two hosts, A
and B, connected by a single link of rate R bps. Suppose that the two hosts
are separated by m meters, and suppose the propagation speed along the link
is s meters/sec. Host A is to send a packet of size L bits to Host B.
a. Express the propagation delay, dprop, in terms of m and s.
b. Determine the transmission time of the packet, ditrans, in terms of L and R.
c. Ignoring processing and queuing delays, obtain an expression for the end-
to-end delay.
d. Suppose Host A begins to transmit the packet at time t = 0. At timer =
drans, where is the last bit of the packet?
e. Suppose drop is greater than dirans. At time t = drans, where is the first
bit of the packet?
f. Suppose drop is less than dirans. At time t = drans, where is the first bit of
the packet?
=
g. Suppose s = 2.5.10%, L = 1500 bytes, and R 10 Mbps. Find the
distance m so that drop equals d