1- Physical - Cabling, USB Bluetooth, Ethernet. 2- Data Link - MAC, 802.3, Switch, 802.11. 3- Network - Datagrams, OSPF, IP, Routing. 4- Transport - TCP, UDP. 5- Session - Full/Half Duplex, Auth. 6- Presentation - Encryption(TLSI), ASCII, YAML. 7- Application - DNS, BGP, HTTP, NTP, RTMP.