CS9213 – Computer Networks and Management - University Questions

CS9213 – Computer Networks and Management / January 2010

Part A – (10 x 2 = 20 Marks)

1.   List any two advantages of virtual paths.
2.  Name any five applications of fibre channel.
3.  Differentiate Committed burst rate from Excess burst rate.
4.  What are the effects of congestion?
5.  State the difference between Constant bit rate and Real time variable bit rate.
6.  What is GFR traffic management?
7.  Draw the DS field and give its significance.
8.  Differentiate elastic applications from inelastic applications.
9.  State the role of Forward Equivalence Class in MPLS.
10.What is RTCP

Part B – (5 x 16 = 80 Marks) 
11.  (a)(i)Draw the ATM protocol architecture and explain in detail. [10]
(ii)Explain the ATM cell format with a neat diagram? [6]  
                         [OR]
(b)(i)Draw the single cell wireless LAN configuration and explain. [10]  
(ii)Write short notes on Fast Ethernet. [6] 

12.  (a)Explain in detail about the following mechanisms used for congestion control.
(i)Choke packet
(ii)Back Pressure
(iii)Implicit congestion signaling and
(iv)Explicit congestion signaling. [4 x 4 = 16]
                         [OR]
(b)Explain in detail about the following frame relay congestion control techniques.
(i)Discard control
(ii)BECN
(iii)FECN 
 (iv)Implicit congestion notification. [4 x 4 = 16] 
13.  (a)(i)Explain the RTT variance estimation in detail (Jacobson Algorithm). [10]
(ii)List out the chief characteristics of the ABR services. [6] 
                         [OR]
(b)(i)Explain the concept of dynamic window sizing on congestion. [10] 
 (ii)Compare the performance of TCP over ATM. [6] 
14.  (a)(i)Explain the concept involved in fair queuing and weighted fair queuing. [5 + 5]
(ii)Explain the RED algorithm. [6]
                         [OR]
(b)Draw the architectures of ISA and explain in detail about its components. [16] 
15.  (a)(i)Write a neat sketch explain the RSVP protocol mechanism. [10]
(ii)What do you mean by label stacking in MPLS? [6] 
                         [OR]
(b)(i)Explain in detail about RTP protocol Architecture. [10]
(ii)List out the RSVP characteristics. [6]

CS9213 – Computer Networks and Management / June 2010

Part A – (10 x 2 = 20 Marks)

1.  How does ATM achieve high speed switching?
2.  What is the principle of binary exponential back off technique? What is its purpose?
3.  In a packet switching network, 24 packets arrive at a particular node in an hour on average. There are typically 8 packets in the node. What is the average time spent by the packet in the node?
4.  What is the need for explicit and implicit signaling mechanisms in frame relay congestion control?
5.  Mention any two advantages of token bucket traffic specification. 
6.    Mention any one advantage and disadvantage of fair queuing. 
7.    Derive an expression for the throughput of TCP sliding window flow control scheme, ignoring TCP overhead. 
8.    What are the objectives of ATM layer traffic and congestion control?
9.  What is the principle of MPLS traffic engineering? 
10.  Why is TCP, not suitable for real time distributed applications?

Part B – (5 x 16 = 80 Marks) 
11.  (a)What is the design goal of fibre channel? What are its requirements and facilities? What are the key elements of a fibre channel network? What are its layers? Explain in detail.  [16]

[OR]

(b)(i)Illustrate the Header Error control algorithm at the receiver in an ATM network. What are the consequences of errors in cell header? [8]

(ii)What is the need for frame relay? How does it differ from conventional packet switching? What are the functions of its layers? Discuss in detail. [8] 
12.  (a)(i)Messages of 4 different sizes flow through a message switch. Fifty percent of the messages take 1ms to serve, twenty percent take 1.5ms to serve, eighteen percent of the messages take 2 ms to serve and the remaining messages take 1.75 ms to serve. Calculate the average time spent in the switch and the average number of messages in the switch, when messages arrive at an average rate of

·         One per 5ms and

·         One per 6 ms                                                             [8]

(ii)What are the principles of explicit congestion signaling techniques? How do they differ from implicit signaling? Explain. [8]

[OR]

(b)Illustrate the objectives of frame relay congestion control. Also illustrate the operation of committed information rate. [16] 
13.   (a)Illustrate the RTT variance estimation technique of TCP congestion control. Also illustrate the operation and role of exponential RTO back off and Karn’s algorithm. [16]

 [OR]

(b)What are the traffic control functions, needed to maintain the Qos of ATM connections? Briefly describe each one of the functions. [16] 
14.  (a)Illustrate the bit by bit processor sharing technique and Bit Round Fair Queuing technique with an example. What are their advantages and disadvantages? [16]

         [OR]

(b)What are the design goals of Random Early Detection? How are they achieved in the algorithm? Discuss. [16] 
15.  (a)Explain the RSVP operation and protocol mechanism. What are the different types of reservation attributes and styles? Discuss. [16]

[OR]

(b)Illustrate the RTP protocol architecture and its features. Also illustrate the basic concept of RTP data transfer protocol. [16]

CS9213 – Computer Networks and Management / January 2012

Part A – (10 x 2 = 20 Marks) 
1.      What is switching? State the switching technique used in ATM network. 
2.      Compare the data rate and speed of Fast Ethernet with Gigabit Ethernet. 
3.      Define congestion. 
4.      What is packet switching?
5.      Define flow control. 
6.      State the significance of window size in TCP. 
7.      What are the components of integrated services? 
8.      State the advantages of random early detection. 
9.      Define label stacking. 
10.  State the need for data transfer protocol.

Part B – (5 x 16 = 80 Marks) 

11.  (a) With a neat bock diagram, explain the ATM protocol architecture.  [16]

[OR]

(b) Describe High speed LAN’s using fibre channel. [16] 
12.  (a) Describe M/M/1 Queuing model. Discuss how the above model can be used in traffic management. [16]

[OR]

(b) Explain congestion control in packet switching networks. [16] 
13.   (a)(i) With diagrammatic illustration discuss TCP timer management. [8]
(ii) Discuss the performance of TCP over ATM. [8]

 [OR]

(b) Discuss the traffic management framework used in ATM networks. [16] 
14.  (a) With a diagrammatic illustration discuss the components of integrated service architecture. [16]

     [OR]

(b) With examples discuss how queuing discipline is maintained in integrated services.    [16] 
15.  (a) Define Quality of Service and discuss RSVP in detail. [16]

[OR]

(b) Describe the operations and label stacking procedures of multiprotocol label switching. [16]