IT430 E-Commerce Assignment 1 Solution Spring 2013

Assignment No. 1


Consider that there is a sales person named Mr. Zee in a Grocery store. He sends every day sales & profit reports on daily basis to Mr. A on e-mail ID “abc@yahoo.com”. Mr. A is the Manager in charge sitting in head office situated in other city.

The Network address of computer machine of Mr. Zee from where he generates the E-mail lies on the network with address 140.57. The e-mail server of the requested e-mail “abc@yahoo.com” is hosted at Network No.100.

For routing the data, there are number of Routers responsible for delivering the data based on IP addressing node to node. There is a router (R-1) attached to network 140.57 and Router (R-2) is the gateway router connected to the network No.100 where destination computer machine lies.

At the sender side the information will pass downward to the TCP/IP layered architecture and upward on receiver after being processed by different protocols on each layer.


What are the protocols that will be responsible in delivery of e-mail from the source to destination, and, also clearly elaborate the functions of the protocol performed downward at sender side and upward at receiver side on the TCP/IP stack?

Only the SMTP (Simple Mail Transfer Protocol) protocol is responsible in delivery of e-mail from the source to destination. The SMTP protocol can only be used to send emails, not to receive them and also depending on our network / ISP settings. Expect of SMTP others protocols are also used in email communication but in different context, these are

  1. IMAP (Internet Message Access Protocol)
  2. POP (Post Office Protocol 3
  3. HTTP protocol


1st.IMAP (Internet Message Access Protocol) :Is is a standard protocol for accessing e-mail from your local server. IMAP is a client/server protocol in which e-mail is received and held for you by your Internet server.

2nd:POP (Post Office Protocol 3): The POP protocol provides a simple, standardized way for users to access mailboxes and download messages to their computers.

3rd:HTTP protocol: The HTTP is not a protocol dedicated for email communications, but it can be used for accessing your mailbox. Also called web based email, this protocol can be used to compose or retrieve emails from an our account.

Functions of the protocol performed downward at sender side and upward at receiver side on the TCP/IP stack:-


Sender:                                                                    Receiver:

From: Mr. Zee                                                       To: Mr. A

Network B class                                                       Network A class

          Able to understand the 4 layers TCP/IP stack/suite/layer
            Data goes both sender side to receiver  through these layer


1st step:

Application layer                                 =>                                Application layer


(Explanation: In this layer two, HTTP and FTP protocols are responsible from both sides sender to receiver. HTTP is using web pages requests and FTP provides an interface and services for file transfer over the network and upload from local to remote & vice versa.)


2nd: step:

Host-to-Host layer/Transport layer     ==>              Host-to-Host layer/Transport layer


(Explanation: It has two function, first one is converts data into packets, and second it is responsible for flow control of data.)


3rd step:

Internet Layer                                     ===>                                   Internet Layer


(Explanation: This layer is providing IP address on data packets using IP protocol. Further, RIP ( Routing Information Protocol ) and ARP ( Address Resolution Protocol) working and operating in Network layer.)


4th step:

Network Access Layer                       ====>                 Network Access Layer


(Explanation: In last step, this layer will placed date into data frames. Now the Network Interface Card Drivers/ Protocols operate at this layer. Is also identify and address hardware of computer machines. Now Mathematical calculation, Cyclical Redundancy Check takes place and confirm integrity of data).


According to the above four steps Mr. Zee will send email and Mr. A will receive email, And the data of email will travel through these layers and receive in his original from to Mr. A.