Nt1330 Unit 3 Network Analysis

NETWORK TECHNOLOGIES (CS553DH1)
SIDDHARTHA BANTUPALLI
ASSIGNMENT-06

1. What are the four noteworthy standards for internet mail architecture listed on the textbook? The four noteworthy standards for internet mail architecture are:
1. Post Office Protocol (POP3)
2. Internet Mail Access protocol (IMAP)
3. Simple Mail Transfer Protocol (SMTP)
4. Multipurpose Internet Mail Extensions (MIME)

Post Office Protocol (POP3):
Email servers which are built on the bases of POP3 standards, allows its users to download their email from the servers. In POP3 user agents are connected to server via TCP/IP protocol, POP3 typically uses TCP/IP port 110 to establish connection between the user client and server. The user enters desired user name and password …show more content…
IMAP also uses TCP/IP protocol to establish a connection between client and server and it uses server TCP port 143 to establish this connection. When compared with POP3, IMAP is more complex and it also provides so many other functions that are not supported by POP3.

Simple Mail Transfer Protocol (SMTP):
SMTP is the standard protocol which is used mostly for transferring mails between hosts. This protocol is mainly used to transfer mail form a user agent to a Message Transfer Agent (MTA) and from MTA to another. SMTP protocol is define in RFC 821.

Message transferred by SMTP usually follow the format defined in RFC 822. Basically, SMTP is not concerned regarding the format or content of the message. SMTP uses information available on the envelope of the mail (Message header) but does not consider the content (message body) of the envelope.

Multipurpose Internet Mail Extensions (MIME): MIME inherits all the properties and characteristics of SMTP and permits the encapsulation of multimedia messages inside a standard SMTP message. MIME is an extension to RFC 822 framework, which address some of the problems and limitations of the use of SMTP. MIME is developed to resolve the problems that are occurred in …show more content…
The user program in User system gets an IP address or an error message.
24.12)

Http Proxy:

Http proxy is a computer system or application that runs on a computer which acts as an intermediary between an endpoint devices. In simple, proxy acts as both client and server from which a user or client requests a service. The main purpose of proxy is, it sends request to server behalf of other client which looks for a service from the server. Http proxy request passed by clients are serviced internally, or forwarding them, by making possible translations, on to other servers. A Proxy must interpret and if necessary it must rewrite a request message before passing it.

Security Intermediary: The client and server are separated by a security intermediary like a firewall, in which proxy will be on the client side of the firewall. Firewall secures the client which is a part in the network whereas server is external to that secured network. In HTTP system, proxy accepts the responses form server once they pass through the firewall.

Different Versions of HTTP: In HTTP system, the proxy performs required mapping for the client and server, if both are running on different versions of HTTP.

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