IT2101 : Communication Technology. 4. Common Network Devices / Hardware Program: BSCS I (January Semester – 2014) Lecturer: Rebecca Asiimwe Email: [email protected] Network Devices.
Network devices are tangible parts of a computer Network that facilitate communication between nodes on the network.
-A Router - A Gateway
-A Switch - A Hub
-Access point - A bridge
-Network Interface Card - Modem
-Networking cables - A Firewall
A network card, network adapter or Network Interface Card (NIC) is a piece of computer hardware designed to allow computers to communicate over a computer network.
Provides a low-level addressing system through the use of MAC addresses. It allows users to connect to each other either by using cables or wirelessly.
The NIC is both an OSI layer 1 (physicallayer) and layer 2 (datalinklayer)device.
A hub contains multipleports. When a packet arrives at oneport, it is copied to all the ports of the hub.
This means that a communication will be exposed to all other connectednodes to the Hub.
It connects multiple devices together & makes them act like a single network segment.
Note: The difference between a Hub and a Switch in Networking.
A small hardware device that joins multiple computers together within one Local Area Network (LAN).
A firewall is a device or set of devices designed to permit or deny network transmissions based upon a set of rules and is frequently used to protect networks from unauthorized access while permitting legitimate communications to pass.
Is a device that extracts the destination of a packet it receives, selects the bestpath to the destination and forwards data packets to the nextdevice along the path.
Note: Routers connect networks together: e.g. LAN to WAN to access the internet
Routers forward data packets along networks by using headers and forwarding tables to determine the best path to forward the packets.
Routers work at the network layer (layer 3) of the OSI model (OSI is to be discussed in a later lecture)
A repeater is an electronic device that receives a signal and retransmits it at a higherlevel or higherpower.
This helps in regenerating the signal since it gets weak as it travelsfurther from its origin.
Thisprocess (weakening of the signal as it travels further from its point of origin) is called attenuation
An Access point