1. First we must note that after the first packet reaches to the first router,
the second packet will be sent, and after the second packet reaches to
first router the third one will be sent.
For the first packet to reach the first router we have:
Propagat
CMPT-371, Assignment-2 Solutions
1. The only side eect of having such channel is increased congestion. The
operation of the Go-Back-N protocol will not be aected. Duplicate
packets will be discarded/ignored at the receiver since they will be
out-of-order.
CMPT 371, Fall 2013 Midterm
1. (20 pts) Suppose we have a TCP connection with a bandwidth of B
Kbit/sec each way, with an RTT of 0.5 seconds and no dropped/delayed
packets. The sender and receiver each have a window of size N (dont
worry about types of wi
CMPT-371, Assignment-3 Solutions
1. In the following graph. The minimum spanning tree (MST) includes
edges (s,a) and (a,b) with a total cost of 2. While the RPF tree include
edges (s,a) and (s,b) with a total cost of 10. Your answer may vary.
s
1
9
1
a
b
CMPT-371, Assignment-4 Solutions
1. All nodes will attempt to transmit at t = 1. Therefore, collision will
occur and no one succeeds. At t = 3, at most two nodes would succeed to transmit. Hence, it is impossible that all nodes would have
successfully tra
CMPT 371: Homework Assignment 4
1. Construct a network with the following properties: The links have symmetric costs in both directions. There is a node s such that the total
cost of the RPF broadcast tree rooted at s is ve times that of the
minimum spann
CMPT 371: Homework Assignment 1
1. I would like to send three packets, of size 1500 bytes each, from point
A to point B. A is connected to Router 1 with a link of lenght l1 meters
and bandwidth b1 bytes/s. Router 1 is connected to Router 2 with a
link of
CMPT 371: Homework Assignment 2
1. Consider a channel that can somehow duplicate a packet (ie, you send
packet x, and another copy of x can be generated without you knowing.
This can happen to ACKs as well. Is this a problem? You can assume
that we are us
CMPT 371: Midterm
1. Give short answers.
(a) In go-back-N the senders and the receivers windows must be the
same size. True of false? .
(b) In the alternating bit protocol the size of the sequence space
is.
(c) . is a mechanism in TCP for preventing the s
CMPT 371: Homework Assignment 4
1. Consider slotted ALOHA. At time t = 0 3 nodes become ready to send a
frame. Let p = 1/2. What is the probability that at time t = 3, that is,
three time slots later, all of them have transmitted successfully? What
is the