Which one among the following protocols works at application layer in a TCP/IP protocol suite?
- A.IP
- B.TCP
- C.TELNET
- D.Go-back-N
Correct answer
Explanation
The correct answer is C, TELNET. TELNET is an application-layer protocol that lets a user log in to a remote computer and work on it through a text terminal.
The TCP/IP suite has four layers: application, transport, internet and network access (link). Application-layer protocols are the ones programs use directly, such as HTTP and HTTPS for the web, FTP for file transfer, SMTP, POP3 and IMAP for e-mail, DNS for name lookup and TELNET and SSH for remote login. TELNET normally uses TCP port 23. Because it sends everything, including passwords, as plain text, it has largely been replaced by the encrypted SSH.
A is wrong because IP works at the internet (network) layer, handling addressing and routing of packets. B is wrong because TCP is a transport-layer protocol that gives reliable, ordered delivery. D is wrong because Go-back-N is an error-control (sliding window) method used at the data link or transport level, not an application protocol.
Exam tip: Application layer = HTTP, FTP, SMTP, DNS, TELNET; transport = TCP, UDP; internet = IP, ICMP.
Practice Questions
View allWhich one among the following is not a part of the SWAYAM programme?
- A.Video lectures
- B.Classroom lectures
- C.Online discussion forum for clearing doubts
- D.Specially prepared material that can be downloaded/printed
Show answer
SWAYAM is an online learning platform, so live classroom lectures are not one of its parts.
Read the full explanation →Which one among the following consists of a list of commands that is executed automatically as the computer system starts up ?
- A.COMMAND.COM
- B.AUTOEXEC.BAT
- C.CONFIG.SYS
- D.AUTOSTART.BAT
Show answer
It is the batch file that MS-DOS runs automatically, line by line, every time the computer starts. A batch file is a plain text file of DOS commands with the.BAT extension.
Read the full explanation →Which one among the following is NOT true about Standard Generalised Markup Language (SGML)?
- A.It is an international open standard
- B.It is dependent on a computer's hardware
- C.It is independent of a computer's operating system
- D.It defines document type
Show answer
SGML was designed to be independent of both hardware and software, so saying it depends on a computer's hardware is false.
Read the full explanation →Which one among the following tasks is NOT carried out by an operating system?
- A.To link a program with the subroutines it references
- B.To manage data transfer to and from peripherals
- C.To allocate memory for storing programs
- D.To provide a layered, user-friendly interface
Show answer
Joining a program to the library routines it calls is the job of a linker, a separate system utility, not of the operating system.
Read the full explanation →Which of the following adopted a law on data protection and privacy for its citizens known as 'General Data Protection Regulation' in April 2016 and started implementation of it from 25th May, 2018?
- A.Australia
- B.Canada
- C.The European Union
- D.The United States of America
Show answer
The General Data Protection Regulation (GDPR) is the European Union's data protection law, adopted in April 2016 and applied from 25 May 2018.
Read the full explanation →