F.Y. M.Tech. (Electronics Engineering) (New CBCS) (Semester
Examination, 2018
voice and data networks
Day and Date Saturday, 8-12-2018 Total Marks 70
Time 10.00 a.m. to 1.00 p.m.
section i
1. Answer following questions.
What are network design issues List various network performance
issues.
What are in-channel and common channel signaling in case of circuit
switching
Suppose a 1-Gbps point-to-point link is being set up between the Earth and a
new lunar colony. The distance from the moon to the earth is approximately
385000 km and data travels over the link at the speed of light-3 ×108 m/s.
C alculate the minimum Rtt for the link.
Using the RTT as the delay, calculate the delay × bandwidth product
for the link.
What is the significance of the delay × bandwidth product computed
in
A camera on the lunar base takes pictures of the Earth and saves them
in digital format to disk. Suppose Mission Control on Earth wishes to
download the most current image, which is of 25 MB size, what is the
minimum amount of time that will elapse between when the request
for the data goes out and the transfer is finished
2. Answer any two from following questions.
List different stations in HDLC. Draw HDLC frame formats and describe
them in detail.
What is retransmission in computer communication Explain ARQ and
hybrid ARQ mechanism.
What are the characteristics of layered architecture What are the benefits
of cross layered communication Discuss two approaches of cross layering
in brief.
Set P
3. Answer following questions.
What is E-1 and T-1 interface in voice communication Draw and
explain E-1 and T-1 frame format. 6
Describe statistical multiplexing in detail. 5
OR
Describe hybrid ARQ mechanism in detail. 5
section iI
4. Answer following questions.
Which different services are expected to provide by end to end communication
protocols Discuss different end to end communication issues.
What are general congestion control policies used in packet networks
What is three-way handshake in case of TCP Describe use of PSH and
URG flag in packet communication.
5. Answer any two from the following questions.
Describe the working of time to live, DF and MF flag in IPv4. With suitable
example describe fragmentation process in IP.
Draw UDP header format and explain its functioning. What is pseudo-header
related to UDP Explain how check sum is calculated in case of UDP.
What are block ciphers Describe DES standard related to encryption.
6. Answer following questions.
E xplain symmetric and asymmetric cyphers in detail. 6
What is QoS What are general techniques to achieve good QoS 5
OR
E xplain DES bit and source-based congestion avoidance policies. 5