Which device works on all OSI Layers?

Network+/Standards/OSI Model/OSI Components

OSI Layer	Purpose	Device
Transport	Reliability	Firewall
Network	Addressing, Routing	Router
Data Link	Logical Link Control, Media Access Control	Switch, Bridge, Access Point
Physical	Transmission	Hub, NIC, Cable, Wireless

What protocols are used at each layer?

TCP/IP Protocol Architecture Model

OSI Ref. Layer No.	OSI Layer Equivalent	TCP/IP Protocol Examples
5,6,7	Application, session, presentation	NFS, NIS+, DNS, telnet , ftp , rlogin , rsh , rcp , RIP, RDISC, SNMP, and others
4	Transport	TCP, UDP
3	Network	IP, ARP, ICMP
2	Data link	PPP, IEEE 802.2

Are protocols used by all devices?

The policies managed by management protocols can be applied to all devices on the network, including computers, switches, routers and even servers. Two of the most common types of network management protocols include Simple Network Management Protocol (SNMP) and Internet Control Message Protocol (ICMP).

What is a protocol device?

A protocol is a standard set of rules that allow electronic devices to communicate with each other. Similarly, if two hardware devices support the same protocol, they can communicate with each other, regardless of the manufacturer or type of device.

What does router do in a network?

A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions on the Internet. Data sent through the internet, such as a web page or email, is in the form of data packets.

What layer is TCP at?

transport-layer
In terms of the OSI model, TCP is a transport-layer protocol. It provides a reliable virtual-circuit connection between applications; that is, a connection is established before data transmission begins.