Rr221901-data-communications

Set No. 1

Code No: RR221901

II B.Tech Supplimentary Examinations, Aug/Sep 2008 DATA COMMUNICATIONS (Electronics & Computer Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) What is Modem? What is the Role of Modem on Data Communications? (b) Based on speed, what are the types of modems and explain.

[8+8]

2. (a) What is Data Communications? Explain briefly Data communication circuit. (b) Mention some standard organizations for Data Communications?

[10+6]

3. (a) What is a transparent switch? A transactional switch. (b) What are the purposes of the nr and ns sequences on SDLC? What is delimiting sequence? [6+10] 4. (a) Draw the block diagram of a typical local area network component configuration and explain. What are the typical characteristics of LAN. (b) Write range of data services, where LAN’s are used extensively.

[10+6]

5. (a) Discuss about principles of queued arbitrated access protocol. (b) Explain the algorithm used to control the transmission of segments on bus A of a dual bus DQDB subnetwork. [6+10] 6. (a) What is ISDN? Describe the services provided by it. (b) Discuss the evolution of ISDN.

[10+6]

7. (a) Differentiate between packet and cell networks. (b) Discuss about asynchronous TDM used by ATM.

[8+8]

8. (a) A user needs to send data at 12Mbps. Which VT(s) can be used? (b) Prove that the user data rate for STS-1 is only 49.536Mbps. ⋆⋆⋆⋆⋆

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[8+8]

Set No. 2

Code No: RR221901

II B.Tech Supplimentary Examinations, Aug/Sep 2008 DATA COMMUNICATIONS (Electronics & Computer Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. Draw the Basic Data Communication Model and explain in detail.

[16]

2. (a) What is Data Communications? Explain briefly Data communication circuit. (b) Mention some standard organizations for Data Communications?

[10+6]

3. (a) What is the Difference between selection and polling? And explain. (b) Explain about Control field on SDLC protocol?

[8+8]

4. (a) What is TOKEN bus and explain? (b) What is the difference between TOKEN bus and TOKEN ring?

[8+8]

5. (a) What is message switching? Discuss about it. (b) Explain two approaches used for implementation of virtual circuit transmission. [8+8] 6. (a) Give bit rates required by different applications. (b) Differentiate between ISDN and broadband ISDN. (c) Differentiate between interactive and distributive services of B-ISDN. [5+6+5] 7. Explain the different attributes to control traffic in frame relay. Also find the relationship between them. [16] 8. (a) What is the relationship between SONET and Synchronous Digital Hierarchy(SDH) (b) Why is SONET called a Synchronous network? ⋆⋆⋆⋆⋆

1 of 1

[10+6]

Set No. 3

Code No: RR221901

II B.Tech Supplimentary Examinations, Aug/Sep 2008 DATA COMMUNICATIONS (Electronics & Computer Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) What is ‘Interface’in Data Communications? (b) Mention any one of the Interface standard, and draw its architecture. [5+11] 2. What is synchronization? Explain about character synchronization? What are the types of data formats. [16] 3. (a) What is the Difference between selection and polling? And explain. (b) Explain about Control field on SDLC protocol?

[8+8]

4. (a) Explain CSMA/CD? (b) Explain TOKEN passing.

[16]

5. (a) Differentiate between PAP and CHAP. (b) Give an overview of different switching methods.

[8+8]

6. (a) Explain different PLP Control packet types with their formats (b) What is X.21 Protocol.

[10+6]

7. (a) Describe different service classes defined by ATM forum. (b) Give network-related attributes of ATM.

[10+6]

8. (a) What is the relationship between SONET and Synchronous Digital Hierarchy(SDH) (b) Why is SONET called a Synchronous network? ⋆⋆⋆⋆⋆

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[10+6]

Set No. 4

Code No: RR221901

II B.Tech Supplimentary Examinations, Aug/Sep 2008 DATA COMMUNICATIONS (Electronics & Computer Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. Explain about transmission of digital data with neat diagram and indicate the signals level at each and every stage. [16] 2. (a) What is Redundancy? With redundancy how will you minimize the errors in data, give any example. Mention advantages and disadvantages of it. (b) How do you detect the errors using Echoplex? Mention advantages and disadvantages of it. [8+8] 3. (a) What is a Protocol? (b) Draw the block diagram of ISO OSI model and explain. 4. Explain about TOKEN RING system?

[3+13] [16]

5. (a) Give slot and segment formats of DQDB. (b) Discuss about SMDS internetworking protocol architectures.

[6+10]

6. (a) What is ISDN? Describe the services provided by it. (b) Discuss the evolution of ISDN.

[10+6]

7. What is the purpose of leaky bucket algorithm. Discuss about it with flow chart and example. [16] 8. (a) Which VT transmits at almost the same data rate as a T-1 line? (b) A company wants to use SONET to multiplex upto 100 digitized voices Which VT(s) is suitable for this company? [6+10] ⋆⋆⋆⋆⋆

1 of 1