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Harsh Kapadia's Computer Networking knowledge base.

OSI Layers

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No. Name Protocol(s) Remarks
7 Application Layer DNS, HTTP, HTTPS, IMAP, POP3, SMTP, SSH Concerned with headers, cookies, content, etc.
6 Presentation Layer   Concerned with encryption.
5 Session Layer   Attach session tag.
4 Transport Layer ALPN, OCSP, SNI, SSL, TCP, TLS, UDP Attach ports and sequence nos. Each individual part is called a segment.
3 Network Layer AH, BGP, EIGRP, ESP, ICMP, IGRP, IKE, IP, IPSEC, ISAKMP, IS-IS, OSPF, RIP Attach IP add. Each individual part is called a packet.
2 Data Link Layer ARP, DHCP Attach MAC add. Each individual part is called a frame.
1 Physical Layer   Data transfer in 1s and 0s.

NOTE: Corresponding to the OSI model, there exists a TCP/IP model as well.