A company operates offices in Delhi, Mumbai, and Bengaluru using dynamic routing. Due to an
incorrect routing update, several routers continue forwarding packets along an invalid route. Explain
how such routing loops occur in Distance Vector Routing. Discuss the Count-to-Infinity problem
and explain any two techniques used to overcome it. 

A university campus has recently upgraded its network infrastructure by replacing copper cables with
optical fiber

Explain the concept of Angle Modulation. Differentiate between Frequency Modulation (FM) and
Phase Modulation (PM). Discuss two practical applications and two limitations of angle
modulation techniques. 

Explain the working principle of optical fiber communication. Compare Step-Index Single Mode,
Step-Index Multimode, and Graded-Index Multimode optical fibers with respect to structure,
transmission characteristics, bandwidth, and applications. 
(b) Describe the TCP/IP reference model. Explain the responsibilities of each layer and identify two
protocols commonly associated with every layer. Also explain how encapsulation takes place while
sending data from an application to the physical network. 

 A sender wants to transmit the binary data 
1101101010
using the generator polynomial
G(x) = x⁴ + x + 1
Calculate the CRC bits and determine the transmitted codeword. Show all intermediate binary
division steps.