Introduction to the TCP/IP Model
The TCP/IP stands for Transmission Control Protocol / Internet Protocol suite was designed and implemented by Department of Defense(DoD) to maintain communication.
TCP first came on the scene way back in 1973, It was divided into two distinct protocols TCP & IP. Later in 1983, TCP/IP replaced the Network Control Protocol (NCP).
About DoD Model
The DoD model is basically a condensed version of the OSI model that comprises four instead of seven layers.
- Process/Application Layer
- Host to Host / Transport Layer
- Internet Layer
- Network Access Layer / Link Layer
Description of TCP & UDP
Firstly our TCP & UDP are come inside the Host to Host layer, & the main purpose of Host to Host layer is to shield the upper layer applications from the complexities of the network.
Transmission Control Protocol (TCP)
The main purpose of Transmission Control Protocol is to takes large block from an application layer and breaks them into segments. It numbers & sequences each segment so that the destination’s TCP stack can put the segments back in to the orders the application intended. After these segments are sent on the transmitting host, TCP waits for an acknowledgement of the reciving end’s TCP virtual circuit session, retransmitting any segments that aren’t acknowledged.
Some key features about TCP are it is full-duplex, connection-oriented, reliable & accurate protocol.
User Datagram Protocol (UDP)
UDP is basically the scaled-down economy model of TCP, It is referred to as a thin protocol. A thin protocol doesn’t require much bandwidth on a network.
Comparison Between TCP & UDP
|Transmission Control Protocol (TCP)||User Datagram Protocol (UDP)|
|Virtual circuit||Low overhead|
|Windowing & flow control||No windowing or Flow control|
Description of Internet Protocol (IP)
The Internet Protocol (IP) works in the Internet Layer. The other protocols found found here merely exist to support it. IP holds the big picture of all the interconnected networks.
It can do this because all the machines on the network have a software, or logical, address called an IP Address.
Merits of TCP/IP model
1.It operated independently.
2.It is scalable.
4.Supports a number of routing protocols.
5.Can be used to establish a connection between two computers.
Demerits of TCP/IP
1.In this, the transport layer does not guarantee delivery of packets.
2.The model cannot be used in any other application.
3.Replacing protocol is not easy.
4.It has not clearly separated its services, interfaces and protocols.