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+20 votes

In one of the pairs of protocols given below , both the protocols can use multiple TCP connections between the same client and the server. Which one is that?

  1. HTTP, FTP
  3. FTP, SMTP
asked in Computer Networks by Boss (40.4k points) | 3.3k views
can anyone confirms that having tcp connection means stateful connection?

@skyby, having TCP connection does not implies stateful connection.

for eg. HTTP uses TCP but a stateless protocol.

2 Answers

+41 votes
Best answer

SMTP: only one TCP connection.


TELNET: only one TCP connection.


HTTP: Multiple connections can be used for each resource.


FTP: FTP uses Telnet protocol for Control info on a TCP connection and
another TCP connection for data exchange

Reference: (See page 8)

So, answer is A. 

answered by Veteran (362k points)
edited by
Yup..I got confused with other answer keys...coz I answered http and ftp..Our point is right :)

@arjun sir  word same   in the above question is having significance ??

link is not working (i've tried multiple times)

any other source?
Hello sir

please clear some of my doubts.

1) Questioner is asking Multiple TCP connection b/w same client and server.Now what do i understand from 'multiple TCP connection' is as follows : TCP connections are identified by port numbers so multiple tcp connection mean at the same time client and server are connected over different ports like in case of ftp , where to transfer 'control information ' client(random port)connect with server on port 21 and in case of 'data transfer' server connect with client by using port 20(in case of active mode). SO here we have multiple tcp connections.Am i right?

2) Sir i'm doubtful about the correctness of your argument for http.The link you attached , is considering a scenario when client is connected to server using some intermediary device like proxy server. and in such case he is claiming that there are multiple connections b/w client and server.Yes i'm agree multiple connections but not multiple 'tcp connection'.for all connections source port and destinations port are same so i consider same TCP connection.Because if in that way we are claiming to have multiple tcp connections then all protocols uses multiple tcp connections because intermediary device can be attached in all cases for security purpose(firewall).did i miss something?

3) put argument like 'HTTP may use different TCP connection for different objects of a webpage if non-persistent connections are used'. it's not clear in question that questioner is asking for 'same session' or we may consider even different sessions as this geeksforgeeks argument? If we can even consider different sessions then i think SMTP can also be true (don't know much about TELNET , so can't argument about it).

4) Let suppose in my browser i opened two tabs , in both i opened 'gateoverflow' and reading two different questions. both time i'm connected to same server and in case of both page request i will have different source ports so that server can distinguish like 'whom response what' so in that way client is connected to same server's same port(port 80) with two source ports. is this case of multiple tcp connection ?

pardon me if i asked something stupid and hence wasted your time.
+3 votes
Option A....most likely
answered by Active (1.2k points)

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