Computer networking devices are units that mediate data in a computer network. Computer networking devices are also called network equipment, Intermediate Systems (IS) or InterWorking Unit (IWU). Units which are the last receiver or generate data are called hosts or data terminal equipment.

List of computer networking devices:

Common basic networking devices:

* Router: a specialized network device that determines the next network point to which it can forward a data packet towards the destination of the packet. Unlike a gateway, it cannot interface different protocols. Works on OSI layer 3.

* Bridge: a device that connects multiple network segments along the data link layer. Works on OSI layer 2.

* Switch: a device that allocates traffic from one network segment to certain lines (intended destination(s)) which connect the segment to another network segment. So unlike a hub a switch splits the network traffic and sends it to different destinations rather than to all systems on the network. Works on OSI layer 2.

* Hub: connects multiple Ethernet segments together making them act as a single segment. When using a hub, every attached all the objects, compared to switches, which provide a dedicated connection between individual nodes. Works on OSI layer 1.

* Repeater: device to amplify or regenerate digital signals received while sending them from one part of a network into another. Works on OSI layer 1. Some hybrid network devices:

* Multilayer Switch: a switch which, in addition to switching on OSI layer 2, provides functionality at higher protocol layers.

* Protocol Converter: a hardware device that converts between two different types of transmissions, such as asynchronous and synchronous transmissions.

* Bridge Router(Brouter): Combine router and bridge functionality and are therefore working on OSI layers 2 and 3.

* Digital media receiver: Connects a computer network to a home theatre Hardware or software components that typically sit on the connection point of different networks, e.g. between an internal network and an external network:

* Proxy: computer network service which allows clients to make indirect network connections to other network services

* Firewall: a piece of hardware or software put on the network to prevent some communications forbidden by the network policy

* Network Address Translator: network service provide as hardware or software that converts internal to external network addresses and vice versa Other hardware for establishing networks or dial-up connections: * Multiplexer: device that combines several electrical signals into a single signal

* Network Card: a piece of computer hardware to allow the attached computer to communicate by network

* Modem: device that modulates an analog "carrier" signal (such as sound), to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information, as a computer communicating with another computer over the telephone network

* ISDN terminal adapter (TA): a specialized gateway for ISDN

* Line Driver: a device to increase transmission distance by amplifying the signal. Base-band networks only.

* Network Device Connectivity

Data terminal equipment:

Data terminal equipment (DTE) is an end instrument that converts user information into signals or reconverts received signals. These can also be called tail circuits. A DTE device communicates with the data circuit-terminating equipment (DCE). The DTE/DCE classification was introduced by IBM.

Basically, V.35 is a high-speed serial interface designed to support both higher data rates and connectivity between DTEs (data-terminal equipment) or DCEs (data-communication equipment) over digital lines.

Two different types of devices are assumed on each end of the interconnecting cable for a case of simply adding DTE to the topology (e.g. to a hub, DCE), which also brings a less trivial case of interconnection of devices of the same type: DTE-DTE or DCE-DCE. Such cases need crossover cables, such as for the Ethernet or null modem for RS-232.

A DTE is the functional unit of a data station that serves as a data source or a data sink and provides for the data communication control function to be performed in accordance with the link protocol.

The data terminal equipment may be a single piece of equipment or an interconnected subsystem of multiple pieces of equipment that perform all the required functions necessary to permit users to communicate. A user interacts with the DTE (e.g. through a human-machine interface), or the DTE may be the user.

Usually, the DTE device is the terminal (or a computer emulating a terminal), and the DCE is a modem or another carrier-owned device.

A general rule is that DCE devices provide the clock signal (internal clocking) and the DTE device synchronizes on the provided clock (external clocking). D-sub connectors follow another rule for pin assignment.

* 25 pin DTE devices transmit on pin 2 and receive on pin 3.
* 25 pin DCE devices transmit on pin 3 and receive on pin 2.
* 9 pin DTE devices transmit on pin 3 and receive on pin 2.
* 9 pin DCE devices transmit on pin 2 and receive on pin 3.

This term is also generally used in the Telco and Cisco equipment context to designate a network device, such as terminals, personal computers but also routers and bridges, that's unable or configured not to generate clock signals. Hence a PC to PC Ethernet connection can also be called a DTE to DTE communication. This communication is done via an Ethernet crossover cable as opposed to a PC to DCE (hub, switch, or bridge) communication which is done via an Ethernet straight cable.