GATE IT 2007 | Question: 69

Question

Consider the following clauses:

1. Not inherently suitable for client authentication.
2. Not a state sensitive protocol.
3. Must be operated with more than one server.
4. Suitable for structured message organization.
5. May need two ports on the serve side for proper operation.

The option that has the maximum number of correct matches is

• A.  IMAP-i;  FTP-ii;  HTTP-iii;  DNS-iv;  POP3-v
• B.  FTP-i;  POP3-ii;  SMTP-iii;  HTTP-iv;  IMAP-v
• C.  POP3-i;  SMTP-ii;  DNS-iii;  IMAP-iv;  HTTP-v
• D.  SMTP-i;  HTTP-ii;  IMAP-iii;  DNS-iv;  FTP-v

Comments

This question answers are more confusing

Answer 1

1. $\text{SMTP}$ which uses $\text{SMTP-AUTH}$ for client side authentication. More read.
   It is wrong to say that HTTP does not provide authentication mechanism – it is just that the mechanism is not secure due to lack of encryption. More read.
2. $\text{HTTP}$ is mostly a stateless protocol though some state mechanisms like cookies are there. More read.
3. $\text{DNS}$  The below paragraph is take from Page 4 of RFC 1035 
   ”The DNS requires that all zones be redundantly supported by more than one name server.  Designated secondary servers can acquire zones and check for updates from the primary server using the zone transfer protocol of the DNS.”
4. $\text{IMAP}$ is suitable for structured message organization. The below paragraph is taken from RFC 3501.
   ”The Internet Message Access Protocol, Version 4rev1 (IMAP4rev1) allows a client to access and manipulate electronic mail messages on a server.  IMAP4rev1 permits manipulation of mailboxes (remote message folders) in a way that is functionally equivalent to local folders.  IMAP4rev1 also provides the capability for an offline client to resynchronize with the server.”
5. $\text{FTP}$ needs two connections – one for data and another for control. The below paragraph is taken from Page 17 of RFC959. 
   ”Both the user and the server-DTPs have a default data port.  The user-process default data port is the same as the control connection port (i.e., U).  The server-process default data port is the port adjacent to the control connection port (i.e., L-1).”

Thus, Option D is the answer as all the five matches are correct.

Answer 2

They are asking for maximum correct matches so

1. Should be $\text{HTTP}$ thus we use $\text{HTTPS}$.
2. $\text{HTTP}$ as it does not depend on state of device or operating system.
3. $\text{IMAP}$ or $\text{DNS}^*$Not sure but they may involve multiple servers.
4. $\text{POP3}$ is suitable for structuring or arranging the folders.
5. $\text{FTP}$ needs two ports,$20$ for data and $21$ for control.

Thus, Option D, As it's matching with $\text{HTTP-2,IMAP-3,FTP-5}$.

Comments

@Priyansh Singh Statement (ii) is asking about statelessness.
Also for the correct explanation of (ii) see this link.
 

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IMAP4 is suitable for message organization not POP3.

Ref:Forouzan page 839.

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1. Should be HTTP thus we use HTTPS.
2. HTTP or SMTP or DNS as it does not depend on the state of the device or operating system.
3. IMAP4 or DNS as they involve multiple servers.
4. IMAP4 is suitable for structuring or arranging folders.
5. FTP needs two ports 20 for the data connection and 21 for the control connection.

 

Answer 3

Option d.

Comments

why ?

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I think ftp uses two ports 21 for commands and 20 for data transfer.. thats all i know.

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@Akash check out my answer.

Answer 4

Option D

Asking for maximum matches

 

C :- SMTP[(ii)-stateless], DNS[(iii)-multiple servers] → 2 matchings

D:- HTTP[(ii)-stateless], IMAP[(iii)-multiple servers], FTP[(v)-2 ports on server side] → 3 matchings

Comments

IMAP4 is responsible for organizing messages in folders. So, C should have 3 matchings.

IMAP

● Developed after POP and attempts to fix POP deficiencies

● allows keeping all mail on the server

● allows mail categorization via folder metaphor

● mail is easily flagged (answered, draft, deleted, seen, recent); this isn’t the same on all servers

● provides for multiple connections to the server