Indira Gandhi National Open University (IGNOU) 2003 Diploma Computer Applications CS09 Data Communications and Networking - - Question Paper

ADCA / MCA (II Yr)
Term-End exam

June, 2003

CS09 : Data Communications and Networking

Time: three hours
Maximum Marks: 75

Note : ques. No. one is compulsory. ans any 3 ques. from the rest.
1. i. discuss the principle of operation of CRC fault detection method. Through an example, show how: (6) a. The fault detection bits are generated.
b. The received frame is checked for transmission errors.
Use the generator polynomial for X4 + x3 + 1.

ii. State the meaning of the subsequent IP addresses: (3)
a. An address with a net id of all 0s.
b. An address with a net id of all 1s.
c. An address with a host id of all 0s.

iii. With the aid of an example, discuss why subnet was introduced. Hence, state the meaning of a subnet router and an address mask. (7)

iv. With the aid of a diagram, discuss how does an Internet congestion algorithm work. (8)

v. Draw a space division 3 stage switch. There are 18 inputs and 20 outputs. Stage one has three switches, Stage two has 2 switches and Stage three has 4 switches. How many cross points are needed to compare this to a system using just 1 crossbar? (6)

2. Differentiate ranging from the following: (15)
i. AAL Protocols
ii. ARP and RARP
iii. Manchester and Differential Manchester encoding techniques with example

3. i. ans the subsequent ques. as applied to token ring protocol: (9)

a. How is the begin and end of a frame detected?
b. The role of a token, monitor, priority and reservation in the access control bits.
c. The role of A and C bits in the frame status field.

ii. What is the advantage of QAM over ASK or PSK? Draw a eight QAM constellation diagram with two amplitude and 4 phases. (6)

4. i. Draw an IP header format and discuss the subsequent (9)
a. Traffic Class
b. Payload length
c. Next header

ii. State why 4B/5B encoding is used in FDDI LANs rather than Differential Manchester encoding. (6)

5. i. Through a diagram discuss the TCP connection management procedure both in normal case and collision case. Also list the states(with their meanings) used in TCP connection management finite state machine. (9)

ii. State the cause why classless inter domain routing was introduced. (6)

6. i. describe the subsequent terms (10)
a. Transponder
b. Source routing bridge
c. Tunnelling
d. Bit Stuffing
e. Wave division multiplexing

ii. discuss the concept of binary exponential backoff algorithm. (5)

Earning:   Approval pending.