BHARAT SEVAK SAMAJ
Final Examination 2007
Time: 2 hrs. Max. Marks: 100
I. Fill in the blanks: (10 x 1 = 10)
1. --------- is an example of bounded medium.
2. Coaxial cables have conductors with --------.
3. In a synchronous modem, the digital to analog converter sends signal to the -----.
4. Multiple repeaters in communication satellites are known as ---------.
5. X.25 standard specifies -------------.
6. In OSI the routing is performed by -----------.
7. In OSI token management is the responsibility of -------------.
8. Binary codes are sometimes transformed in modems into -------------.
9. ----------has the longest transmission distance.
10. The purpose of preamble in Ethernet is -----------.
II. State whether True or False: (10 x 1 = 10)
1. A signal is periodic if it completes a pattern within a time frame.
2. Digital signals are classified as simple and complex.
3. Period refers to the amount of time.
4. The period of a signal is its number of cycles per second.
5. The phase refers to the position of the waveform relative to zero.
6. In digital signals 1 is positive voltage.
7. The bit rate is the time required to send one single bit.
8. Decoder can transform information into signals.
9. As frequency increases, the period decreases.
10. The term sampling means measuring the amplitude ate equal intervals.
III. Answer any SIX of the following: (6 x 10 = 60)
1. What are the performance problems in computer networks?
2. Explain the issues related to network security.
3. What is inverse multiplexing?
4. Describe briefly the various transmission media used.
5. Construct hamming code for the bit sequence 10011101.
6. What is checksum? Explain its functions.
7. Explain any two error correction codes.
IV. Answer any ONE of the following: (1 x 20 = 20)
1. Draw TCP and UDP segment formats.
2. Explain using a table, the various protocols used in different layers of the OSI model.