Networking

Different arrangements of computer connections and devices

A central cable is used to connect all the devices with terminators at the end of the cable so the signal doesn’t bounce back

The central cable in a bus topology

A signal is sent via the main cable which reaches all the the connected devices The signal contains a destination address to identify the recipient and a source address to identify the sender MAC address are hardcoded in the Network Interface Controller of each device Devices must detect if they are transmitting at the same time so they can stop to avoid collision

A bus setup doesn’t allow 2 computers to transmit at the same time as it causes collisions When network is in heavy use, the overall performance decreases as collisions increase If the main cable breaks it brings the whole network to a stop Devices can eavesdrop on each other

Media Access Control address- An address given to a network interface controller used to uniquely identify devices on a local network

Network Interface Controller- A component that allows a device to connect to a network

A bus topology with a coaxial cable as the backbone All the computers are connected by a special interface cable which plugged into a NIC connecting the computer and the cable

Includes the CSMA/CD rules and the need to send destination and recipient MAC addresses Specifies the structure of the data sent via hardware

A blue print for the structure of data, it has 5 different fields for the pieces of information needed for transmission

Data transmitted Destination address Source address Type field FCS (Frame check sequence)

Frame Check Sequence- Used to detect whether errors have occurred during transmission

Unshielded Twisted Pair cable, a type of cable where two conductors are twisted together to reduce interference

A UTP cable connects each computer to a central device (e.g. a hub) which sends signals to all the computers Each cable acts like a bus network as the hub has no understanding of what the signals mean

A network computer that is used to connect devices on a LAN, it learns which device is connected to each port so it can direct traffic

A UTP cable connects each computer to a central device (e.g. a switch) which sends signals to all the computers The switch learns the address of each device connected to its ports by looking at source MAC addresses. It builds a table mapping each port-device connection so it can direct incoming data to a specific device If an unknow destination address is sent it defaults to hub behaviour

A central powerful computer (server) Client computers

A computer on a network that provides resources to be used by authorised clients Access level granted by the server is controlled by the handler

The most common type of server Store and provide webpages

A computer or computer controlled device that provides user access to a network They run software to make requests to servers then interpret/display the response They send requests to the server which processes it and returns it

Web services, game hosting and private networks

No central server All computers have equal roles & access rights They share portions of their resources Network security & resource management is not controlled centrally so backs have to occur locally

LANs, file sharing networks

A set of rules specific to wireless communication