1 (i) Suppose that the Aloha Protocol is used to share
a 56 Kbps satellite channel. Suppose that packets are
1000 bits long. Find the maximum throughput of the system
in packets/second. [7]
(ii) Does Ethernet provide connection oriented or connectionless
service? How is the transfer of frames in Ethernet similar
to the transfer of frames in a packet switching network?
How is it different? [5]
(iii) What difference does it make to the network layer
if the underlying data link layer provides a connection
oriented service versus a connectionless service? [5]
(iv) Use IEEE 802.3 and IEEE 802.11 to discuss three
differences between wired and wireless LANs. [5]
(v) · Identify the address class of the following
IP addresses: 208.58.20.165 and 128.167.23.20.
· Identify the range of IPV4 addresses spanned
by class A, Class B and class C. [5]
(vi) List the important QoS ATM parameters. [3]
2 (i) Discuss the important features of the following
techniques:
(a) Wavelength Division Multiplexing
(b) PCM
(c) Delta Modulation (DM)
What are the improvements of DM over PCM? [10]
(ii) A signal is transmitted digitally over a 4-KHz
noiseless channel with one sample every 125 m sec. How
many bits per second are actually sent for the following
encoding methods?
· DPCM with a relative signal value
· DM [5]
3 (i) A 10 kHz baseband channel is used by digital
transmission system. Ideal pulses are sent at the Nyquist
rate, and the pulses can take 8 levels. What is the
channel capacity of the system?
(ii) Discuss the following transmission techniques
for wireless transmission:
(a) Microwave Transmission
(b) Radio Transmission
(c) Infra-red
4 (i) Discuss the following in the context of token
ring: [9]
· How does token ring define the start and end
delimiters?
· Main problems of a token ring network and methods
used to overcome them.
· Main advantages of MAUs in a token ring network.
(ii) With reference to transport layer, outline the
operation of 3-way handshaking. How does the 3-way handshake
prevent old duplicate connection initiation from causing
confusion? [3]
(iii) Discuss the possible scenario for a transport
connection over a connection-oriented network layer.
[3]
5 (i) Discuss the important features of the following
internet control protocols:. [10]
· The Address Resolution Protocol (ARP)
· Open Shortest Path First (OSPF)
(ii) Explain the data format of ISDN. [5]
6 Discuss the following: [15]
(i) Internet multicasting
(ii) Firewalls
(iii) Multipurpose Internet Mail Extensions
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