|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.