Session Layer: Software layers ^Is responsible for establishment of connection, authentication and security between the devices.
Transport Layer: Heart of OSN model. End to end delivery of the complete message.
Network Layer: Transmission of data from one host to the other if both of the devices are located at different networks.
Data Link Layer: With the data link layer is responsible for node to node delivery of messages in physical layer.
Physical Layer Hardware layers ^: responsible for actual physical connection between devices. It carries information in bit format. It has certain functions. It has certain functions such as bit synchronization, bit rate control.
reject information: rejects traffic with a report.
gateways: rejects traffic without giving a message.
IP (Internet protocol)
Public IP: Dynamic. Changes every time you connect to the internet.
Private IP: Static.
ipv4: Previously established internet protocol. First version of ip. It uses 32 bit address scheme which means it has 4 billion addresses. Only has numbers.
ipv6: latest version of ip which is more secure because it uses 128 bit address Scheme. Has Hexadecimal values.