1 (a) Using the Nyquist theorem, calculate the sampling
rate for the following analog signals: [8]
· An analog signal with bandwidth 2000 Hz
· An analog signal with frequencies from 2000
to 6000 Hz
(b) What is the minimum number of samples for PCM encoding
if the frequency ranges from 1000 to4000Hz? [5]
(c) What is the difference between bit rate and baud
rate? Give an example where both are the same. Give
an example where they are different. [5]
(d) Show by calculation how many hosts per network
each IP address class (A,B and C only) can have? [5]
(e) In two byte address fields what is the maximum
number of permanent virtual circuits possible? What
about a 3 byte address? [7]
2 Answer the following questions:
(a) Contrast the IEEE 802.3 frame with HDLC I-frame.
[5]
(b) Contrast the IEEE 802.5 frame with HDLC I-frame.
[4]
(c) Why is there no AC field in 802.3 frame? [3]
(d) What are the advantages of FDDI over a token ring?
[3]
3 Compare and comment on the following :
(a) Ethernet, token ring and FDDI in terms of access
method, address length, signaling, data rate and error
control. [6]
(b) Transport and source routing bridge in terms of
orientation, transparency, configuration, routing, locating,
failures and complexity. [6]
(c) Datagram subnet and virtual circuit subnet in terms
of effects of router failure and congestion control.
[3]
4 (a) Describe the working principle, advantage and
disadvantage of the following routing algorithms:
· Reverse path forwarding
· Multicast routing
Also describe various ways of pruning the spanning tree.
[10]
(b) Comment on five important quality of service parameters
defined by the ATM standard. [5]
5 Answer the following questions associated with congestion
algorithms:
(a) Difference between token bucket and leaky bucket
algorithms. [4]
(b) Describe all the parameters used in flow specification
technique. [4]
(c) Rate based congestion algorithm in ATM. [7]
6 Discuss the following question related to the transport
layer:
(a) Many features of the transport layer (e.g., flow
control and reliable delivery) are also handled by the
data link layer. Is this duplication of effort ? why
or why not? [3]
(b) What are the problems with 2-way handshake in connect
establishment and connection termination? How does 3-way
handshake resolve it? Explain through diagrams. [6]
(c) Upward multiplexing and downward multiplexing.
[6]
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