Computer Networ...

Which of the following protocol pairs can be used to send and retrieve e-mails respectively?

Match the following protocol with its corresponding port number.

Which pair of protocols will use only single TCP connections between the same client and the server?

Choose the most appropriate answer among the given pairs.

Which application layer protocol uses EHLO command?

Consider the following statements about electronic mail:

S1: When both sender and receiver are connected to the mail server via a LAN or a WAN, we need two user agents, two message transfer agents and message access agents.

S2: SMTP can be used in all message transfer phases (connection establishment, mail transfer and connection termination) to put the messages from the client to the server and to get back the messages from the server to the client.

S3: SMTP is a push protocol and POP3 is a pull protocol.

Which of the above statement/s is/are TRUE?

Which of the following is/are the stateless Application layer protocol?

P) DNS

Q) HTTP

R) POP3

S) UDP

Consider a client makes a request for a web page through his web browser to a web server. The web browser is configured to send HTTP requests in non-persistent mode. The web page contains text and 3 small images. Initially, the browser cache of the client is empty. What is the product of the minimum number of TCP connections required to display the web page completely in the client's browser?

Identify the correct order in which the following actions take place in an interaction between a web browser and a web server.

1. The web browser requests a webpage using HTTP.

2. The web browser establishes a TCP connection with the web server.

3. The web server sends the requested webpage using HTTP.

Which is/are the limitation of SMTP?

I. No encryption

II. transfer only ASCII messages

III. No authentication

What of the following is/are true about the FTP protocol?

I. It is out-of-band protocol

II. It is stateless protocol