Overview Of Tcp/Ip And Its Services

TCP/IP is an acronym for Transmission Control Protocol/Internet Protocol.TCP/IP is a collection of protocols,applications and services.The protocols in TCP/IP move data from one network layer to another.
There are five layers within TCP/IP.
? Application
? Transport
? Inernet
? Data Link
? Physical

The Physical Layer
The Physical layer is pure hardware in any network infrastructure. This includes the cable,satellite,or any other connection medium,and the network interface card.
The Data Link Layer
The layer that is responsible for splitting data into packets to be sent across the connection medium such as cables,satellites,and so on. The Data Link Layer works hard to make sure that the physical link does not garble the electrical signals carrying the data.


The Network Layer
Layer gets packets from the Data Link Layer and sends them to the correct network address. One possible route is available for the data to travel,the network layer figures out the best route.
The Transport Layer
The Network Layer routes data to its destination,it cannot guarantee that the packets holding data will arrive in the correct order or that they won't have picked up any errors during transmission.
The Application Layer
Which contains the application that the user uses to send or receive data.without this layer the computer and its user would never be able to send data and would not know what to do with data sent by another user.
Internet Protocol
The Internet Protocol is responsible for basic network connectivity.when mapped to the TCP/IP layers,the Internet Protocol or IP works with The Network Layer.
Why IP address is not same?
The IP address can be compared to a postal address that indentifies the exact location of a residence or corporate house. Two residences cannot have the same postal address,so also no two computers on a TCP/IP network can have the same IP address.

The Structure of an IP Address
The IP address is a set of numbers separated by periods. IP address is a 32-bit number,divided into two sections,the network number and the host number. Addresses are written as four fields,eight bits each separated by a period. Each field can be a number ranging from 0 to 255.This method of addressing is called dotted decimal notation.An IP address looks likeL
field.field2.field3.field4

Transmission Control Protocol/Internet Protocol(Tcp/Ip)
TCP/IP uses IP to deliver packets to the upper layer applications and provides a reliable stream of data among computers on the network.TCP/IP consists of protocols,applications,and services,Protocols enable a server application to offer services,and the client application to use those services.It is possible to design a new protocol and add it to TCP/IP. The Internet is a large worldwide network of computers,which uses TCP/IP as the underlying communication protocol.

World Wide Web
The world wide web is a worldwide information service on the internet. HyperText Transfer Protocol or HTTP is the protocol used by the WWW service to make communication possible between a Web Server and a Web Browser.

FTP
File Transfer Protocol is not just a protocol but also a service and an application. FTP provides the facility to transfer files between two computers running on different operating systems such as UNIX,MS-DOS and Windows.





FTP As An Application
FTP  is an application for copying files.A client application can be run on the local computer to contact the FTP server application on the remote computer. CuteFTP and Reachout are two very popular FTP applications,which provide excellent user interfaces and a wide range of FTP commands and functions.

FTP As A Service
FTP is a service for copying files from one computer to another. A connection can be made from one computer (Client) to another computer (Server) offering this service and files can be sent or received.

FTP As A Protocol
FTP is a protocol for copying files between two computers.The client and the server applications both use it for communication to ensure that the new copy of the file is identical to the original.

Telnet
Telnet is both a TCP/IP application and a protocol for connecting a local computer to a remote computer. The Telnet application acts as a terminal emulator. Whatever commands are typed into the local computer are sent across the network for execution by the remote computer. Once connection established ,it ask username and password to access remote computer.