Application-Layer-Protocol
Question 1 |
Which of the following protocol pairs can be used to send and retrieve e-mails (in that order)?
SMTP, MIME | |
SMTP, POP3 | |
IMAP, POP3 | |
IMAP, SMTP |
Question 1 Explanation:
SMTP & POP3 are the protocols which are responsible for the email communication, SMTP is responsible for outgoing mail & POP3 is responsible for retrieving mail.
POP3: Post Office Protocol (Responsible for retrieve email)
SMTP: Simple Mail Transfer Protocol (Responsible for send Email)
IMAP: Internet Message Access protocol (Responsible for store and view)
MIME: Multi purpose Internet Mail Extensions (For media)
POP3: Post Office Protocol (Responsible for retrieve email)
SMTP: Simple Mail Transfer Protocol (Responsible for send Email)
IMAP: Internet Message Access protocol (Responsible for store and view)
MIME: Multi purpose Internet Mail Extensions (For media)
Question 2 |
Which of the following is/are example(s) of stateful application layer protocols?
(i) HTTP
(ii) FTP
(iii) TCP
(iv) POP3
(i) HTTP
(ii) FTP
(iii) TCP
(iv) POP3
(i) and (ii) only | |
(ii) and (iii) only | |
(ii) and (iv) only | |
(iv) only |
Question 2 Explanation:
Stateless protocol is a communications protocol in which no information is retained by either sender or receiver.
A protocol that requires keeping of the internal state on the server is known as a stateful protocol.
Stateless - HTTP, IP
Stateful - FTP, SMTP, POP3, TCP
TCP is stateful as it maintains connection information across multiple transfers, but TCP is a Transport layer protocol.
FTP and POP3 is stateful Application layer protocol.
A protocol that requires keeping of the internal state on the server is known as a stateful protocol.
Stateless - HTTP, IP
Stateful - FTP, SMTP, POP3, TCP
TCP is stateful as it maintains connection information across multiple transfers, but TCP is a Transport layer protocol.
FTP and POP3 is stateful Application layer protocol.
Question 3 |
The protocol data unit (PDU) for the application layer in the Internet stack is
Segment | |
Datagram | |
Message | |
Frame |
Question 3 Explanation:
The PDU for Data Link layer, Network layer, Transport layer and Application layer are frame, datagram, segment and message respectively.
Question 4 |
Consider different activities related to email:
- m1: Send an email from a mail client to a mail server
m2: Download an email from mailbox server to a mail client
m3: Checking email in a web browser
Which is the application level protocol used in each activity?
m1: HTTP m2: SMTP m3: POP | |
m1: SMTP m2: FTP m3: HTTP | |
m1: SMTP m2: POP m3: HTTP | |
m1: POP m2: SMTP m3: IMAP |
Question 4 Explanation:
Sending an email will be done through user agent and message transfer agent by SMTP, downloading an email from mail box is done through POP, checking email in a web browser is done through HTTP.
Question 5 |
What is the maximum size of data that the application layer can pass on to the TCP layer below?
Any size | |
216 bytes-size of TCP header | |
216 bytes | |
1500 bytes |
Question 5 Explanation:
Application Layer - Any size
Transport Layer - 65515 byte
Network layer - 65535 byte
Data link layer - 1500 byte
Transport Layer - 65515 byte
Network layer - 65535 byte
Data link layer - 1500 byte
Question 6 |
Assume that you have made a request for a web page through your web browser to a web server. Initially the browser cache is empty. Further, the browser is configured to send HTTP requests in non-persistent mode. The web page contains text and five very small images. The minimum number of TCP connections required to display the web page completely in your browser is ______.
6 |
Question 6 Explanation:
In non-persistent HTTP connection for every object, there is a TCP connection established. Therefore, 1 TCP connection for text and 5 TCP connections for images required.
Hence, 1 Text + 5 Image = 6 Objects
Hence, 1 Text + 5 Image = 6 Objects
Question 7 |
Which of the following protocol is used for transferring electronic mail messages from one machine to another?
TELNET | |
FTP | |
SNMP | |
SMTP |
Question 7 Explanation:
TELNET→ Telephone network
FTP→ File transfer protocol
SNMP→ Simple network management protocol
SMTP→ Simple mail transfer protocol Simple Mail Transfer Protocol (SMTP): is an Internet standard for email transmission.
→ Mail servers and other mail transfer agents use SMTP to send and receive mail messages on TCP port 25.
FTP→ File transfer protocol
SNMP→ Simple network management protocol
SMTP→ Simple mail transfer protocol Simple Mail Transfer Protocol (SMTP): is an Internet standard for email transmission.
→ Mail servers and other mail transfer agents use SMTP to send and receive mail messages on TCP port 25.
There are 7 questions to complete.