- Device used:
- Physical layer or below: Hubs, Repeaters, Cables, Fibers, Wireless.
- Data-link layer: Bridges, Modems, Network cards, 2-layer switches.
- Network layer: Routers, Routers, 3-layer switches.
- Transport layer: Gateways, Firewalls.
- Session layer: Gateways, Firewalls, PCs.
- Presentation layer: Gateways, Firewalls, PCs.
- Application layer: Gateways, Firewalls, and all end devices like PCs, Phones, and Servers.