1. No category

Chapter 1
Q1: What is the role of the router?
Q2: When a node in LAN1 wants to send a message in a node in LAN2.
How it can process?
Q3: How we can get ADSL internet in the house?
Q4: What is the type of the network that we can have in a university?
Q5: will it be preferable to use in this LAN a star topology with a hub or a switch?
Q6: Give three types of server?
Q7: What are the drawbacks of a bus topology?
Q8: How we can identify, in a given time, a device uniquely in the network?
Q9: How we can identify uniquely an application in this device?
Q10: In a company there are two sites, how we can build the network of the company and
what it the type of the built network?
Q11: Give the best example of a WAN?
Q12: How we can improve the performance of a Ring topology?
Q13: what is the number of links in a mesh topology containing N devices?
Q14: What it the minimum number of ports in a router?
Q15: Explain what are TCP and IP.
Q16: What is the definition of protocol?
QMC
Communication between a computer and a keyboard involves ______________ transmission
a) Automatic
b) Half-duplex
c) Full-duplex
d) Simplex.
A set of rules that governs data communication
a) Protocols
b) Standards
c) RFCs
d) None of the mentioned
Three or more devices share a link in ________ connection
a) Unipoint
b) Multipoint
c) Point to point
d) None of the mentioned
Which of the following is required to communicate between two computers?
a. communications software
b. protocol
c. communication hardware
d. all of above including access to transmission medium
In a ................topology, if there are n devices in a network, each device has n-1 ports for
cables.
A) Mesh
B) Star
C) Bus
D) Ring
Name of the topology in which there are bidirectional links between each possible nodes
A.
Ring
B.
Mesh
C.
Star
D.
Tree
Communication mode which supports data in both directions at the same time is called
A.
simplex
B.
Full duplex
C.
Half duplex
D.
multiplex
Which of the following is/ are the drawbacks of Ring Topology?
A) Failure of one computer, can affect the whole network
B) Adding or removing the computers disturbs the network activity.
C) If the central hub fails, the whole network fails to operate.
D) Both of A and B
Chapter2
QMC
Two devices are in network if
a) a process in one device is able to exchange information with a process in another device
b) a process is running on both devices
c) none of the mentioned
Communication channel is shared by all the machines on the network in
a) broadcast network
b) unicast network
c) multicast network
d) none of the mentioned
A _____ is a device that forwards packets between networks by processing the routing
information included in the packet.
a) bridge
b) firewall
c) router
d) all of the mentioned
Network congestion occurs
a) in case of traffic overloading
b) when a system terminates
c) when connection between two nodes terminates
d) none of the mentioned
In the layer hierarchy as the data packet moves from the upper to the lower layers, headers are
a) Added
b) Removed
c) Rearranged
d) Modified
The _______ is the physical path over which a message travels
a) Medium
b) Protocol
c) Route
OSI stands for
a) open system interconnection
b) operating system interface
c) optical service implementation
d) none of the mentioned
The OSI model has ___ layers.
a) 4
b) 5
c) 6
d) 7
TCP/IP model does not have ______ layer but OSI model have this layer.
a) session layer
b) presentation layer
c) application layer
d) both (a) and (b)
Which address is used in an internet employing the TCP/IP protocols?
a) physical address and logical address
b) port address
c) all of the mentioned
TCP/IP model was developed _____ the OSI model.
a) prior to
b) after
c) simultaneous to
d) none of the mentioned
Which layer is responsible for process to process delivery?
a) network layer
b) transport layer
c) session layer
d) data link layer
Which address identifies a process on a host?
a) physical address
b) logical address
c) port address
d) specific address
Which layer provides the services to user?
a) application layer
b) session layer
c) presentation layer
d) none of the mentioned
The data link layer takes the packets from _____ and encapsulates them into frames for
transmission.
a) network layer
b) physical layer
c) transport layer
d) application layer
Which one of the following is a data link protocol?
a) ethernet
b) point to point protocol
c) Token Ring
d) all of the mentioned
The technique of temporarily delaying outgoing acknowledgements so that they can be
hooked onto the next outgoing data frame is called
a) piggybacking
b) cyclic redundancy check
c) fletcher’s checksum
d) none of the mentioned
The network layer concerns with
a) bits
b) frames
c) packets
d) none of the mentioned
Which one of the following is not a function of network layer?
a) routing
b) inter-networking
c) congestion control
d) none of the mentioned
The IP address can be
a) network address
b) host address
c) both (a) and (b)
d) none of the mentioned
The network layer protocol of internet is
a) ethernet
b) internet protocol
c) hypertext transfer protocol
d) none of the mentioned
When data is encapsulated, which is the correct order?
a) Data, frame, packet, segment, bit
b) Segment, data, packet, frame, bit
c) Data, segment, packet, frame, bit
d) Data, segment, frame, packet, bit
The resources needed for communication between end systems are reserved for the duration
of session between end systems in ________
a) Packet switching
b) Circuit switching
TCP/IP ................. layer corresponds to the OSI models to three layers.
A) Application
B) Presentation
C) Session
D) Transport
Which of the following applications allows a user to access and change remote files without
actual transfer?
A) DNS
B) FTP
C) NFS
D) Telnet
Which layers of the OSI determines the interface often system with the user?
A) Network
B) Application
C) Data link
D) Session
The ............layer of OSI model can use the trailer of the frame for error detection.
A) Physical
B) Data link
C) Transport
D) Presentation
Which layer deals with Network topology
A.
Physical Layer
B.
Datalink Layer
C.
Network Layer
D.
Session Layer
Which layer sends and receives bits
A.
Session Layer
B.
Physical Layer
C.
Datalink Layer
D.
None of above
MAC address is of how many bits
A.
24 bit
B.
32 bit
C.
48 bit
D.
128 bit
Which application protocol deals with emails
A.
FTP
B.
SMTP
C.
http
Which protocol finds the MAC address from IP address
A.
SMTP
B.
ICMP
C.
ARP
Which layer deals with TCP and UDP
A.
Transport Layer
B.
Physical Layer
C.
Network Layer
D.
None of above
Questions
1) Give a comparison between TCP and UDP.
2) Give two layer 1 devices can be used to enlarge the area covered by a single LAN
segment?
3) Give the layers in which operate the Routers, the LAN switches the Ethernet hubs and the
4) Why does the data communication industry use the layered OSI reference model?
5) What is the purpose of flow control?
6) What is the purpose for segmentation with a bridge?
7) Segmentation of a data stream happens at which layer of the OSI model?
8) Explain the role of the switches.
9) What is the role of Windowing in the TCP layer ?
10) Explain the figure presented below
11) Supposing the figure below:
a) What is the number of LANs that we have in this figure?
b) What is the number of nodes in each LAN?
c) Explain the operation of frame sending in each LAN.
Chapter 3
QCM
The physical layer concerns with
a) bit-by-bit delivery
p) process to process delivery
c) application to application delivery
d) none of the mentioned
Physical layer provides
a) mechanical specifications of electrical connectors and cables
b) electrical specification of transmission line signal level
c) all of the mentioned
The physical layer is responsible for
a) coding
b) modulation
c) all of the mentioned
The physical layer translates logical communication requests from the ______ into hardware
specific operations.
a) data link layer
b) network layer
c) trasnport layer
d) application layer
Transmission data rate is decided by
a) network layer
b) physical layer
c) data link layer
d) transport layer
Which one of the following task is not done by data link layer?
a) framing
b) error control
c) flow control
d) coding
Which performs modulation and demodulation
A.
Modem
B.
Fiber optic
C.
satellite
D.
coaxial cable
Questions
1) Supposing L is the number of bits in the packet and R is the transmission rate, give the total
end to end delay in sending a packet P, if there are N routers from source to destination.
2) Define modulation.
3) A digital signal has nine levels. How many bits are needed per level?
4) Encode the sequence 010011 with Manchester and Differential Manchester coding:
5) What is the advantage of Manchester coding ?
6) What are the propagation time and the transmission time for a 5-Mbyte message (an image)
if the bandwidth of the network is 1 Mbps? Assume that the distance between the sender and
the receiver is 12,000 km and that light travels at 2.4 × 108 m/s. (Interpret the result)
General Review
1) Explain how does the ARP protocol work?
2) Give the routing table for each router in the figure below.
3) Explain the data transparency in the data link layer presenting an illustrative example
4) Which of the following address does not belong to the same network(no subnetting)?
Explain why?
1. 130.31.23.31
2. 130.31.24.22
3. 130.32.23.21
5) Whey the network layer is unreliable?
Packets can be lost (destructed by a router with a full buffer) and can arrive in disorder since
every packet can follow a different way.
6) What are the two alternatives for the operation of the central node in STAR topology ?
7) How can a device have more than one IP address?
8) What is the purpose of the timer at the sender in systems using ARQ?
9) Give an example of LRC and VRC error detection.
10) Propose three subnetting IP addresses relative to this IP address 141.14.0.0
11) Cite four advantages of wireless networks
12) Networks can include the following devices:
• repeaters
• bridges
• routers
For each device, describe:
a. the function of the device;
b. an example of an appropriate application;
c. the highest level at which the device operates according to the ISO OSI model.
13) What are the similarities and the difference beween virtual circuit switching and circuit
switching (give an example of each switching type)?
14) Where is the special IP address 127.0.0.0. used?
15) Compare go-back-N and selective-repeat ARQs.
16) Explain the advantages of go-back-N compared to Stop and wait