# Tutorial

Δίκτυα και Επικοινωνίες

24 Οκτ 2013 (πριν από 4 χρόνια και 6 μήνες)

302 εμφανίσεις

SEMESTER
-
VI

C
S

610
7

COMPUTER NETWORKS

TUTORIAL SHEET

DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING
,
B. I. T. MESRA

Module

I
: Foundati on

1.

What is a computer network? Identify the set of constraints and requirements that influence
network design.

2.

Wh
at is a switched network? Explain the circuit
-
switched and packet
-
switched networks with
help of diagram.

3.

Characterize the networks according to their size.

4.

What are the three general classes of failures that network designers have to address? Explain.

5.

E
xplain the layered network architecture.

6.

What is a protocol and protocol graph?

7.

What happens during the Encapsulation process? Explain.

8.

Explain the OSI and Internet architecture.

9.

Describe the client
-
server architecture and the complete communication proces
s.

10.

Enumerate and explain the protocol implementation issues.

11.

Differentiate between bandwidth and throughput of a communication link.

12.

Discuss the bandwidth and latency performance metrics of a link/channel. How will you relate
these two metrics?

13.

Define roun
d
-
trip
-
time and jitter.

14.

Calculate the total time required to transfer a 1.5 MB file in the following cases, assuming a RTT
of 80 ms, a packet size of 1 KB data, and an initial 2*RTT of “handshaking” before data is sent.

a.

The bandwidth is 10 Mbps, and data p
ackets can be sent continuously.

b.

The bandwidth is 10 Mbps, but after we finish sending each data packet we must wait
one RTT before sending the text.

c.

The link allows infinitely fast transmit, but limits bandwidth such that only 20 packets
can be sent per R
TT.

15.

Consider a point
-
to
-
point link 2 km in length. At what bandwidth would propagation delay (at a
speed of 2*10
8

m/sec)

equal transmit delay for 100
-
-
byte packets?

16.

How “wide” is a bit on a 1
-
Gbps link? How long is a bit in c
opper wire, where the speed of
propagation is 2.3*10
8
m/s?

Module

II

and
III

17.

What is a Network adapter and what are its functional components? Give examples of a few
network adapter models available in the market.

18.

How the memory
bandwidth limits the network performance? Discuss with the help of an
example.

19.

List the common types of cables and fibers available for local links.

20.

Enumerate the common bandwidths available from various carriers.

21.

List and explain the common services avail
able like POTS, ISDN, xDSL, CATV etc to connect
your home to an existing network.

22.

What is the Encoding process and explain the different encoding strategies.

23.

What are byte
-
oriented and bit
-
oriented protocols?

24.

How the error detection and correction is done
when errors are introduced into frames?

25.

How reliability is ensured while transmission of frames? With the help of a timeline diagram
explain the four different scenarios for the stop
-
and
-
wait ARQ.

26.

Consider a scenario in which the link has a delay x bandwid
th product of 8 KB and frames are of 1
KB size. We would like the sender to be ready to transmit the 9
th

frame at pretty much the same
moment that the ACK for the first frame arrives. Propose a suitable algorithm to handle this
situation.

27.

Explain the Eth
ernet IEEE 802.3 standard.

28.

Explain the IEEE 802.5 standard.

29.

Explain the FDDI.

30.

Explain the Resilient Packet ring IEEE 802.17 satandard.

31.

Compare the following technologies on the issues like link length, bandwidth, use, and wired
technology analogy: Bluetoo
th, Wi
-
Fi, WiMax, 3G Cellular
.

32.

Explain the 802.11 frame format.

33.

Show the 4B/5B encoding, and the resulting NRZI signal, for the following bit sequence: 1101
1110 1010 1101 1011 1110 1110 1111

34.

Consider an ARQ protocol that uses only NAKs, but no ACKs. Desc
ribe what timeouts would
need to be scheduled. Explain why an ACK
-
based protocol is usually preferred to a NAK
-
based
protocol.

35.

What is the Ethernet capture effect?

Module

IV

and
V
: Internetworking

36.

What
are the various addressing schemes that an IP ser
vice model provides? Explain.

37.

Enumerate the different categories of connecting devices based on the layer in which they operate
in a network.

38.

Write note on bridges, switches, and routers.

39.

Why address translation is required and how it is accomplished using

the ARP?

40.

What do you mean by static host configuration and dynamic host configuration? Compare them.

41.

What is the role of Internet control Message Protocol? Explain in detail.

42.

What are Virtual private networks and what necessitates them?

43.

Explain the routin
g process in distance
-
vector routing.

44.

Discuss the different major classes of intradomain routing protocols.

45.

With the help of an example scenario calculate the link costs to compare the various routing
algorithms.

46.

What is Subnetting and when do we need it.

Explain with the help of an example scenario.

47.

What is Interdomain routing? Explain BGP and EGP.

48.

Compare IPv4 and IPv6.

49.

What is the Multicasting and when do you need this? Explain considering an example scenario.
Also explain how to accomplish this.

50.

What i
s MPLS and how it is associated more with IP’s datagram based architecture?

51.

How do routers determine that an incoming IP packet is to be multicast?

Module

VI
: End
-
to
-
End Protocols

52.

Explain the TCP and UDP process.

Also show the TCP and UDP header format
.

53.

Differentiate between flow control and congestion control.

54.

What is the significance of TTL and MSL of a packet on the network?

55.

Explain the Nagle’s algorithm and its significance.

56.

What are the shortcomings of Karn/Partridge algorithm that are shorted in J
acobson/Karels
algorithm?

57.

Explain the complete RPC mechanism.

Module

VII
: Congestion Control and Resource Allocation

58.

What is the resource allocation problem in the networking context?

59.

Explain the different ways to

characterize the resource allocation
mechanisms?

60.

How will you evaluate a resource allocation mechanism? Explain the points.

61.

Describe the Queuing algorithm used for packet transmission.

62.

How congestion control is achieved in TCP?

63.

What mechanisms are adopted for congestion avoidance?

64.

Enumerate v
arious protocols and mechanisms used to provide QoS to different applications.

65.

What are the two broad categories of approaches to QoS support?

**********