Note that some of the questions may be ambigous. You must state any assumptions you make in your answer.
For instance, for problem #3 you might assume that all connections are between nodes in the network, or you might assume that the network is a subnet that might also have a connection to a larger network (such as the Internet).
Furthmore, you might assume that time-division multiplexing or frequency-division multiplexing is being used. Your must state your assumption as part of your answer.
Problem #3 refers to Figure 1-5 which is not in the first edition of the textbook. You can view that Figure here.
You may use the following conversions without stating them as assumptions:
Consider the frosting-and-conveyor-belt analogy for a sender, a single link, and a receiver, as introduced in class today. Suppose that the sender outputs 3 bits per second, and that the conveyor belt is 4 meters long and moves at 10 cm/sec. Suppose that packets are 40 bits long.
Add a router
and a second link identical to the first, so
that there are two 4-meter conveyor belts in succession. Suppose
that there is a processing delay of 8 seconds to begin
retransmitting a packet at the router.
Calculate how long it
would take to transfer a file
consisting of 15 packets
across the two links. (You can think of the file
as a
message
in the terminology we've been using in class.)
A1.