Jawaharlal Nehru Technological University Hyderabad B.Tech III NETWORK PROGRAMMING Previous Question Paper (February/March - 2022 - R18)

The OSI model defines seven layers, each providing specific services for network communication:

1. Physical Layer: Handles transmission of raw bit streams over a physical medium, defining electrical, mechanical, and functional specifications.
2. Data Link Layer: Provides node-to-node data transfer, framing, physical addressing, and error detection/correction.
3. Network Layer: Manages logical addressing, routing, and path determination to facilitate data transfer between different networks.
4. Transport Layer: Ensures end-to-end communication, flow control, segmentation, and reliability (e.g., TCP/UDP).
5. Session Layer: Establishes, manages, and terminates sessions between applications, handling synchronization and dialog control.
6. Presentation Layer: Manages data representation, encryption, and compression to ensure the application layer can read the data.
7. Application Layer: Provides network services directly to end-user applications, such as HTTP, FTP, and SMTP.

Internet address conversion functions are used to translate between human-readable strings and network-byte-order binary structures.

1. inet_aton: Converts an ASCII dotted-decimal string to a network byte order binary address.
   int inet_aton(const char *cp, struct in_addr *inp);
2. inet_ntoa: Converts a network byte order binary address to a dotted-decimal string.
   char *inet_ntoa(struct in_addr in);
3. inet_pton: Converts an IP address from text to binary form, supporting both IPv4 and IPv6.
   int inet_pton(int af, const char *src, void *dst);
4. inet_ntop: Converts an IP address from binary to text form, supporting both IPv4 and IPv6.
   const char *inet_ntop(int af, const void *src, char *dst, socklen_t size);