B.E.IB.Tech.  DEG;REE EXA.MINATION, APRILIMAY 2015.

Fourth  Semester

Computer  Science and Engineering

CS 6551 - COMPUTER NETWORKS (Regulation 2013)

Time:  Three hours

Answer ALL questions. PART A - (10 x 2 = 20 marks)

1.	What  do you mean  by error  control'? 

2.	Define flow control. 

3.	What  do you understand   by CSMA protocol? 

4.	List the functions  of bridges. 

5.	How does a router  differ from a bridge? 

6.	What  are the metrics  used by routing  protocols? 

7.	List some of the Quality  of Service  parameters   of transport  layer. 

8.	How does transport  layer perform  duplication  control? 

9.	Define SMTP. 

10.	What  are the groups  of HTIP  header? 

PART B -  (5 x 16 = 80 marks)		
11.   (a)   Discuss  in detail  about  Internet  Architecture.	(16)	
Or		

(b)	What  is the  need  for  error  detection?  Explain  with  typical  examples. 

Explain  methods  used for error  detection  and error correction.	(16)	

12.	(a)   Explain  in detail  about  the  access  method  and  frame  format  used  in 

	Ethernet  and token ring.		.(16)	
		Or			
(b)	(i)	Discuss the MAC layer functions	of IEEE802.11	(8)	
	(ii)	Briefly define key requirements	of wireless LAN	(8)	
13.   (a)	Explain the shortest  path algorithm  with suitable illustrations.	. (16)	
		Or			

(b)	Explain the distance vector routing algorithm.  Mention the limitations  of 

the same.	(16)	

14.	(a)   Explain the various fields of the 'i'CP header  and the working of the TCP 

protocol.	(16)	

Or

(b)	(i) Explain  the  three  way  handshake   protocol  to  establish   the 

transport  level connection.	(8)	

(ii)	List the various congestion control mechanisms.  Explain anyone  in 

15.	(a)   (i)    Explain the message transfer  using Simple Mail Transfer  Protocol. 

(8)

(ii) Explain the final delivery of email to the end user using POP3. (8) Or

(b)	Write short notes on 

(i)	Web services	(8)	
(ii)	SNMP.	(8)	

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