TCP/IP (Networking)

TCP/IP is developed by Department of Defence(DoD). There are 4 layers in this model. some says 5.

Network Access Layer: This is the combination of Physical and Data Link Layer of OSI model

. Physical layer is responsible for actual physical connection. For e.g: Routers, modem etc. And Data Link Layer is responsible for node to node delivery of message. The main function of this layer is to make sure to transfer date from one to another in error free from.

Internet Layer:- This layer is also known as Network Layer in OSI model. It helps to transfer data from one host to another located in different network. The main protocol used by this layer are IP, ARP, ICMP etc.

Host-to-Host Layer(Transport Layer):- This layer is also known as Transport Layer in OSI model. It is responsible for end to end delivery of the message. Protocol used by this layer is Transmission Control Protocol(TCP) and User Datagram Protocol(UDP). If error occur it helps to re-transmit the data.

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, Telnet, SSH, SMTP, SNMP, NTP, DNS, DHCP, NFS, X Window, LPD.