4. Networks and the effects of using
them
Network
A computer network is a set of computers sharing resources located on or provided by
network nodes
common network devices and terms
4 important parts of a network
» network interface card (NIC)
» media access control (MAC) address
» internet protocol (IP) address
» data packet.
Network interface card (NIC)
A network interface card (NIC) is a hardware component in the motherboard needed to allow
a device to connect to a network by converting binary data into an electrical signal.
Media access control (MAC) address
The media access control (MAC) address is a number made up of 48 bits which uniquely
identifies a device when it is connected to a network.
its shown as 6 groups of hexadecimal digits where the first one 3 groups are the
manufacturers code and the rest is the device serial number.
Internet protocol (IP) addresses
An IP address is a unique string of characters that identifies a device on the internet or a local
network and its location.
Internet protocols define the rules that must be agreed by senders and receivers of data.
Data packets
A data packet is a unit of data made into a single package that travels along a given network
path.
4. Networks and the effects of using them 1
, Packets of data will usually have a header which contains:
» the sender’s IP address
» the receiver’s IP address
» the sequence/identity number of the packet (this is to ensure that all the packets can be
reassembled into the correct order once they reach the destination)
» the packet size (this is to ensure the receiving station can check if all of the packets have
arrived intact)
» how many data packets make up the whole message.
Hub
Hubs are hardware devices that form a local area network by having a number of other
devices connected to them
A hub will take a data packet received at one of its ports and broadcast it to every device
connected to it.
their disadvantages include that they are not very secure and cause unnecessary traffic.
Switches
switches connect a number of devices together to form a LAN by storing the MAC addresses
of all the devices where each port on the switch has a matching MAC address called a lookup
table.
a switch sends and receives data Using the look-up table, a switch matches the MAC address
of an incoming data packet arriving at one of its ports, and directs it to the correct device.
Bridges
Bridges are devices that connect one LAN to another LAN that uses the same protocol
(communication rules). They are often used to connect together different parts of a LAN so
that they can function as a single LAN.
Routers
Because each router has its own IP address they are used to route data packets from one
network to another network, based on IP addresses and join a LAN to the internet.
how it works?
When a data packet is received at one of its ports, the router inspects the IP address and
determines whether the data packet is meant for its own network or for another, external
network. If the data packet is meant for its own network, then the data packet is routed to the
local switch or hub. Otherwise, the data packet is transmitted to a different router
ROUTER VS BRIDGE
4. Networks and the effects of using them 2
them
Network
A computer network is a set of computers sharing resources located on or provided by
network nodes
common network devices and terms
4 important parts of a network
» network interface card (NIC)
» media access control (MAC) address
» internet protocol (IP) address
» data packet.
Network interface card (NIC)
A network interface card (NIC) is a hardware component in the motherboard needed to allow
a device to connect to a network by converting binary data into an electrical signal.
Media access control (MAC) address
The media access control (MAC) address is a number made up of 48 bits which uniquely
identifies a device when it is connected to a network.
its shown as 6 groups of hexadecimal digits where the first one 3 groups are the
manufacturers code and the rest is the device serial number.
Internet protocol (IP) addresses
An IP address is a unique string of characters that identifies a device on the internet or a local
network and its location.
Internet protocols define the rules that must be agreed by senders and receivers of data.
Data packets
A data packet is a unit of data made into a single package that travels along a given network
path.
4. Networks and the effects of using them 1
, Packets of data will usually have a header which contains:
» the sender’s IP address
» the receiver’s IP address
» the sequence/identity number of the packet (this is to ensure that all the packets can be
reassembled into the correct order once they reach the destination)
» the packet size (this is to ensure the receiving station can check if all of the packets have
arrived intact)
» how many data packets make up the whole message.
Hub
Hubs are hardware devices that form a local area network by having a number of other
devices connected to them
A hub will take a data packet received at one of its ports and broadcast it to every device
connected to it.
their disadvantages include that they are not very secure and cause unnecessary traffic.
Switches
switches connect a number of devices together to form a LAN by storing the MAC addresses
of all the devices where each port on the switch has a matching MAC address called a lookup
table.
a switch sends and receives data Using the look-up table, a switch matches the MAC address
of an incoming data packet arriving at one of its ports, and directs it to the correct device.
Bridges
Bridges are devices that connect one LAN to another LAN that uses the same protocol
(communication rules). They are often used to connect together different parts of a LAN so
that they can function as a single LAN.
Routers
Because each router has its own IP address they are used to route data packets from one
network to another network, based on IP addresses and join a LAN to the internet.
how it works?
When a data packet is received at one of its ports, the router inspects the IP address and
determines whether the data packet is meant for its own network or for another, external
network. If the data packet is meant for its own network, then the data packet is routed to the
local switch or hub. Otherwise, the data packet is transmitted to a different router
ROUTER VS BRIDGE
4. Networks and the effects of using them 2
