December 2001

Question Paper of CS-09 – Data Communication & Network of December 2001 from IGNOU

Time: 3 hours
Maximum Marks: 75

Note: Question 1 is compulsory. Attempt any 3 from the remaining.

1 (a). Describe the salient features of mobile IP.3

(b). Describe the various issues related to measuring network performances.6

(c).Identify the range of IP v4 addresses spanned by Class A, Class B and Class C.3

(d).Give three examples of protocol parameters that might be negotiated when a connection is set up with reference to the transport layer.- 3

(e).Are there any circumstances when a virtual circuit service will (or at least should) deliver packets out of order ? Explain. – 3

(f).If we want to transmit 1000 ASCII characters using asynchronous transimssion, what is the minimum number of extra bits needed ? What is the efficiency in percentage ? – 6

(g).What is the major disadvantages is using NRZ encoding ? How do RZ encoding 6 and biphase encoding attempt to solve the problem ?

2 (a). A 10 KHz baseband channel is used by digital transmission system. Ideal pulses are sent at the Nyquist rate and the pulses can take 4 levels. What is the channel capacity of the system ? -6 marks

(b). Discuss the following transmission techniques for wireless transmission : 9
( i ).Microwave Transmission
( ii ).Radio Transmission
( iii ).Infrared transmission

3 (a).Compare and contrast the following :15

( i ).IEEE 802.3 frame and HDLC I-frame
( ii ).100 BASE F and 100 BASE T cable specification
( iii ).Circuit switching and Packet switching
( iv ).B-channels and D-channels
( v ).Upward and Downward multiplexing with reference to the transport layer

4 (a).Comment on packet fragmentation approaches in internetworking. -5

(b).Why is there a need for compression ? Compare between JPEG and MPEG standards. -4

(c). Measurment of a slotted Aloha channel with an Infinite number of users show that 10 percent of the slots are idle. -6

( i ).What is the channel load ?
( ii ).What is the throughput ?

5 (a).What is the acknowledgement procedures in IEEE 802.5 protocol ? -3

(b).Compare the effect of a node failure in CSMA/CD and token passing ring. -3

(c) With reference to transport layer outline the operation of 3-way handshaking. How does the 3-way handshake prevent old duplicate connection request andduplicate connection request and acknowledgement ? – 3

(d)Describe the channel utilization versus load for various random access protocols. Show it graphically and compare mathematically slotted Aloha Vs Pure Aloha. – 6

6 (a) Where is the multicasting routing used ? Describe its advantages and disadvantages.-5

(b)Describe a suitable congestion control algorithm with an example used for multicasting routing. – 5

(c).Describe the functioning of the combined Batcher – Banyan 4 cell switch.5

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