Transport Layer

Before entering another layer in Lower layer, first of all we must know about transport layer.
What is transport layer? What is the function for this layer?
This layer segment and reassembles data into a data stream.

The example device /fitur for this layer is firewall.

There are 2 protocol in this layer that you must know.
The protocol is TCP and UDP.

TCP = transmission control protocol.
UDP = user datagram protocol

TCP is usually used by FTP. UDP is used by voice.

The Difference between TCP and UDP:

TCP
—-
connection oriented
Flow Control
3 way handshake
Overhead -> The sent data is more bigger than total size because it contain header information
Reliable
Header 20 byte

UDP
—
Connectionless
Header 8 byte
Fast data delivery
Unreliable

The Transport Layer is responsible for providing mechanisms for multiplexing upper-layer applications, establishing sessions, and tearing down virtual circuit.
It also hides detail of any network-dependent information from the higher layers by providing transparent data transfer.

Multiplexing is a technic that sending more than 1 information using 1 channel.
The purDatagrampose of multiplexing is to save the total of physical channel like cable, transceiver, optic cable,etc.

MTU (Maximum Transmission Unit) is a maximum data limitation that can being send by a one frame in Network Interface Layer in TCP/IP. Layer Network Interface is not desain to accept or sending frame that contain more than MTU that we config.a one Datagram IP is a must lower or same size with MTU or it can’t be encapsulation for sending.(Comer, 2001)