TCP/IP MODEL tutorial

                       TCP/IP MODEL

The OSI model we just look at in just a reference/logical model. It was designed to describe the functions of the communication system by dividing the communication procedure into smaller and simller components.

           But when we talk about the TCP/IP model, it was designed and devoloped by DEPARTMENT OF DEFENSE (DOD) in 1960s and is based on standard protocol, It stands for Transmission Control Protocol/Internet Protocol. The TCP/IP model is a concise version of the OSI model.

             LAYERS IN TCP/IP MODEL

It contains four layers, unlike seven layers in the OSI model.

• Process/Application layer.
• Host-to-Host/Transport layer.
• Internet layer.
• Network Access/Link Layer.

• Application Layer:- To allow access to network resources.

• Transport Layer:- To provide reliable process massage delivery and error delivery.

• Internet Layer:- To move packets from source to destination to provides internetworking.

• Network Interface:- Responsible for the transmission for the between two device on the same network.

            NETWORK ACCESS LAYER

• This layer corresponds to the combination of data link layer and physical layer of the OSI model.
• It looks out for hardware addresing and the protocols present in this layer allows for the physical transmission of data.
• It helps you to defines details of how data should be sent using the network.
• It also includes how bits should optically be signaled by hardware devices which directly interface with a network medium, like COAXIAL,OPTICAL,FIBER or TWISTED-PAIR CABLES.

                       INTERNET LAYER

• An internet layer is a second layer of the TCP/IP model.
• It is also known as a network layer.
• The main work of this layer is to send the packets from any network, and any computer still they reach the destination.
• The main protocols resinding at this layer are………….

                      1. IP,   2.ICMP, 3.ARP.

                HOST-TO-HOST LAYER

• This layer is analogous to the transport layer of the OSI model.
• It is responsible for end-to-end communication and error-free delivery of data.
• The two main protocols present in this layer are……………..

                    1.TCP (Transmission control protocol)

                    2.UDP (User datagram protocol)

                     TRANSPORT LAYER

• Transport layer helps you to control the reliability of a link through flow control, error control and segmentation on de-segmentation.
• The transport layer also offers an acknowledgment of the succesful data transmission and sends the next data in case no errors occurred.

                  APPLICATION LAYER

• This layer performs the functions of top three layers of the OSI model…...APPLICATION, PRESENTATION and SESSION layer.
• It is responsible for node-to-node communication and controls user-interface specifications.
• Some of the protocols present in this layer are…….HTTP, HTTPS, FTP, TFTP, Telent, SSH, SMTP, SNMP, NDP, DNS, DHCP.

The diagrammatic comparison of the TCP/IP and OSI model---------

TCP/IP model                             OSI model

                                                         Application layer

1. Application layer                   Presentation layer

                                                    Session layer

2.Transport layer                       Transport layer

3.Internet layer                           Network layer

4.Network access layer             Data link layer

                                                     Physical layer

 Difference between TCP/IP and OSI model…

TCP/IP model                       OSI model

1.TCP refers to transmission  1.OSI refers to open           

   Control protocol                     system interconnection.

2.TCP/IP has 4 layer.                   2.OSI has 7 layer.

3.TCP/IP is more reliable.            3.OSI is less reliable.

4.TCP/IP does not have very       4.OSI has strict 

   Strict boundaries                       boundaries.

5.TCP/IP develop protocols       5.OSI developed model 

   Than model                                than protocol.

6.TCP/IP follow a horizontal.      6.OSI follows a vertical   

                                                         approach.

What is protocol?

• A protocol is a standard set of rules that allow electronic devices to communicate with each other.
• These rules include what type of data may be transmitted, what commands are used to send and receive data, and how data transfers are confirmed.

SOME IMPORTANT PROTOCOLS………

• IP:- It's stand for internet protocol and it is responsible for delivering packets from the source host to the destination host by looking at the IP addresses in the packet headers.

• ICMP:- Stands for internet control massage protocol. It is encapsulated with in IP datagrams and is responsible for providing hosts with information about network problems.

• ARP:- Stands for address resolution protocol. It job is find the hardware address of a host from a known IP address.

• TCP:- It is known to provide reliable and error-free communication between end system.

1. It performs sequencing and segmentation of data.
2. It also has acknowledgement feature and controls the flow of the data through flow control mechanism.

• UDP (user datagram protocol):-

1. It is the go to protocol if your application does not require reliable Transport as it is very cost effective.
2. Unlike TCP which is connection-oriented protocol, UDP is connection less.

• HTTP and HTTPS:-

1. HTTP stands for Hyper Text Transfer Protocol. It is used by the world wide to manage communication between web browsers and servers.
2. HTTPS stands for HTTP-SECURE. It is a combination of HTTP with SSL (secure socket layer).
3. It is efficient in cases where the browser need to fill out forms sign in, authenticate and carry out bank transactions.

• TELNET:- Telnet is a protocol. That allows you to connect to remote computer, called host over a TCP/IP network.

• SSH:-

1. SSH stands for SECURE SHELL. It is a terminal emulations software similar to Telnet.
2. The reason SSH is more preferred is because of its ability to maintain the encrypted connection.

• NTP:-

1. NTP stands for NETWORK TIME PROTOCOL .
2. It is used to synchronize the clocks on our computer to one standard Time source.
3. It is very useful in situations like bank transaction.

• FTP:- FTP is a network protocol used to transfer files from one computer to another over a TCP network.

• SNMP:- It stands for SIMPLE NETWORK MANAGEMENT PROTOCOL is an application layer protocol used to manage and monitor network devices and their functions.