Tcp/ip (transfer Control Protocol/internet Protocol) Model

TCP/IP (Transfer Control Protocol/Internet Protocol), is responsible for full-fledge data connectivity and transmitting data from one user to another. TCP handles the message part which is broken down into packets and then transmitted over the network. The packets are then received by equivalent TCP protocol in the receive and reassemble into the original message. The IP is primary affecting the transmission portion. The IP addresses are assigned to each other and any active user/recipient on the network. However, TCP/IP is broken down into four layers which includes Network Interaction layer, Internet layer, Transport layer and Application layer and they all are responsible for managing different sections of transmission process.

Moreover, there are other protocols that are linked with TCP/IP such as:

• FTP- File Transport Protocol lets the users to interchange files over the Internet. FTP uses Internet’s TCP/IP protocols to allow data transfer. FTP is commonly used for downloading a file from a server using the Internet or to uploading a file to the server
• HTTP- HyperText Transfer Protocol lets the users of World Wide Web to interchange information found on the web pages. This protocol states how messages are formatted and transmitted and what actions web servers and browsers should take acknowledgement to various commands. For example, when the user enters URL in their browser, this sends an HTTP command to the web server directing it to fetch and transmitting the requested web page.
• SMTP- Simple Mail Transfer Protocol and it is used for sending emails messages between the servers. An email messages can be sent over the Internet using SMTP protocol to send messages from one server to another; the messages can be then retrieved with an email client using either POP or IMAP protocols. Generally, SMTP is used to send messages from a mail client to a mail server, which is why the client needs to specify both the POP or IMAP server and the SMTP server when configuring the email application

The Network Interaction Layer

The network interaction layer is the lowest layer of the TCP/IP model and it could be also referred as the link layer. The network interaction layer combines both with physical and data link layer function into a single layer. It also includes frame physical network functions like modulation line coding and bit synchronisation, frame synchronisation and error detection, and LLC and MAC sublayer functions. For this layer, the most common protocols include Address Resolution Protocol (ARP), Neighbour Discovery Protocol (NDP), IEEE 802.3 and IEEE 802.11.

The Internet Layer

The internet layer is the layer that contains the packet construct that will be transmitted. This takes the form from IP protocol which describes the packet containing a source of IP address, destination of IP address and the actual data to be delivered. The functions include: traffic routing, traffic control, fragmentation, and logical addressing. For the internet layer, the most common protocols are IP, ICMP and IGMP.

The Transport Layer

The transport layer is next layer and it is responsible of message segmentation, acknowledgement, traffic control, session multiplexing, error detection and correction, and message reordering. The common protocols include Transport Control Protocol (TCP) and User Datagram Protocol (UDP).

The Application Layer

The application layer is the highest layer in the TCP/IP model and is associated to the session, presentation and application layers of OSI layer. The application layer in TCP/IP model is used for handling all process-to-process communication functions. There are various different functions that are carried out by this layer, including session establishment, maintenance and termination, character code translations, data conversion, compression and encryption, remote access, network management, electronic messaging etc. For this layer, the most common protocols are: FTP, SSL, HTTP, SMTP etc.