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.
Firewall functions
accept information: Allows traffic.
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.
DNS: domain name.
TCP/IP architectures
TCP
Stands for: Transmission Control Protocol
Synchronization: follows it and therefore is good for chatting.
Used at server and client end.
Layer 1: Application and presentation are merged together
Layer 2: Session Layer:
Layer 3: Transport layer network layer and data link layer are merged together