Process-to-Process Delivery

Process-to-Process Delivery: A transport-layer protocol's first task is to perform process-to-process delivery. A process is an entity of the application layer which uses the services of the transport layer. Two processes can be communicated between the client/server relationships.

Client/Server Paradigm

There are many ways to obtain the process-to-process communication, and the most common way is through the client/server paradigm. A process is called a client on the local-host. Usually, the remote host is needed services on the processes, that is called server. The same name applies to both processes (client and server). IP address and port number combination are called socket address, and that address defines a process and a host.

Multiplexing and Demultiplexing

Multiplexing: At the sender site, multiple processes can occur, and those processes are required to send packets. It is a technique that combines multiple processes into one process.

Demultiplexing: At the receiver site, it is a technique that separates many processes.

UDP (User Datagram Protocol)

UDP was developed by David P Reed in 1980. It is a connection-less and unreliable protocol. This means when the data transfer occurs; this protocol does not establish the connection between the sender and receiver. The receiver does not send any acknowledgment of the receiving data. It sends the data directly. In the UDP, the data packet is called datagram. UDP does not guarantee your data that will reach its destination or not. It does not require that the data reach the receiver in the same order in which the sender has sent the data.

Transmission Control Protocol

TCP stands for Transmission Control Protocol. It was introduced in 1974. It is a connection-oriented and reliable protocol. It establishes a connection between the source and destination device before starting the communication. It detects whether the destination device has received the data sent from the source device or not. If the data received is not in the proper format, it sends the data again. TCP is highly reliable because it uses a handshake and traffic control mechanism. In TCP protocol, data is received in the same sequencer in which the sender sends the data. We use the TCP protocol services in our daily life, such as HTTP, HTTPS, Telnet, FTP, SMTP, etc.

Difference between UDP and TCP

UDP	TCP
UDP stands for User Datagram Protocol.	TCP stands for Transmission Control Protocol.
UDP sends the data directly to the destination device.	TCP establishes a connection between the devices before transmitting the data.
It is a connection-less protocol.	It is a connection-oriented protocol.
UDP is faster than the TCP protocol.	TCP is slower than the UDP protocol.
It is an unreliable protocol.	It is a reliable protocol.
It has not a sequence number of each byte.	It has a sequence number of each byte.