OSI Model 7 Layer:
Application Layer
presentation Layer
Session Layer
transport layer
Data Link Layer
Physical Layer
Application Layer
1. client-server protocol
a) HTTP (one-way communication request from client and response from server) 1 connection create hota hai
b) FTP ( 2 connection maintain hote hai, 1 control connection ( hamesha bana rahta hai, 1 data connection ( data connection can be created and disconnected)) FTP mai data is not encrypted, so it is not secure to we don’t use it. we use HTTPS instead
c) SMTP used with IMAP and pop3 kai sath use karte hai
SMTP for sending the email, IMAP for reading/accessing the e-mail, pop3 is not used these days because after download they get deleted.
d) web socket (bi-directional communication but not peer-to-peer i.e two client are not communicating )
web socket used in messaging app
2. peer to peer Protocol
web RTC : which uses UDP to transfer the data
Transport / Network Layer Protocol
- TCP / IP
a) ordering maintain
b) acknowledge
c) connection maintain hote hai - UDP/ IP ( live streaming, video calling), webRTC UDP protocol use karti hai
a) no connection maintain
b) no ordering maintain
c) no acknowledge
d) fast (as only send the data)