Network: Network is computer and device connected ti each other with to wireless (wi-fi / li-fi).
Open System Interconnection
THE SEVEN LAYER OF OSI
Transmit Data User Receive Data
| Application (Layer - 7) |
| Presentation (Layer - 6) |
| Session (Layer - 5) |
| Transport (Layer - 4) |
| Network (Layer - 3) |
| Data Link (Layer - 2) |
| Physical (Layer - 1) |
|-------------------------------- Physical Link --------------------------------|
Allocation (Layer - 7): Application is a protocol like STP, HTTP, HTTPS etc.
Presentation (Layer - 6): Converting the data or extension in UTC (mp4/mp3)
Session (Layer - 5): Its associate the user to clients.
Transport (Layer - 4): This is the main protocol of TCP/UDC.
Network (Layer - 3): IP Protocol using the router.
Data Link (Layer - 2): This is the SWITCH protocol layer.
Physical (Layer - 1): Transform to data layer from digital data to analog data.
Socket: Socket is the communication mechanism that allows clients / server to connect to each other with specific rule.
Socket Programming: Socket programming of connecting two node on a network to communicate to each other. Server form to listener socket while client reach out to the server.
---------- ----------
| Server | | Client |
---------- ----------
| |
Socket |
| |
Setsockopt |
| |
Bind |
| |
Listen <---------------------- Connect
| |
Accept |
| |
Send/Recv <-----------------> Send/Recv
TCP: Transmission Control Protocal
UDP: User Datagram Protocal
-------------------------------------------------------------------------
| TCP | UDP |
-------------------------------------------------------------------------
| Reliable | Unreliable |
------------------------------------------------------------------------|
| Connection Orinented | Connectionless |
------------------------------------------------------------------------|
| Segment retransmission and | No windowing or retransmission|
| flow control through | |
| windowing. | |
------------------------------------------------------------------------|
| Segment sequencing | No sequencing |
------------------------------------------------------------------------|
| Acknowledgement | No acknowledgement |
-------------------------------------------------------------------------
Raw Sockets: Raw socket is an internet socket that allows direct sending and receiving of internet protocol packets without any protocol (TCP/UDP) specific transport layer formatting. Example, RAW SOCKET is used for DDoS (Distribute Denial of Server Attack) attack.