Communications And Networking Flashcards
LANs
Local area network.
Confined to one site.
Node
A device on a network
Adv. of LANs
Data sharing is easy, backups easier, computers in a network are easily updated, computers easily monitored, security policies centrally administered, users can communicate, peripherals can be shared
Disad. Of LANs
Maintenance expensive, network problems affect all users, data accessible from many places so security may be a problem
WANs
Wide area network.
Covers a large geographical area, which often connect LANs together and allow business to function from any location
Network hardware
This is special hardware needed to connect computers
NICs
Network interface controllers/cards. Each device on a network needs one, aka LAN adaptor. Usually built into the motherboard. Every one has a unique number stored in rom, called its MAC (media access control) address which allows each node on a network to be identified.
Connections between devices on most LANs are made with…
Copper cable, usually known as UTP ( unshielded twisted pair)
For longer distances, fibre optic cable is used.
Hubs
Hardware devices which connect many devices together, making them into a single network segment. They have a number of input and output ports which connect to each other
Switches
These connect network segments or devices. They can also act as BRIDGES which connect more than one network.
Wireless access points
Allow connection to a LAN without the need for physical cables. Use standards such as wifi. They are often connected to a ROUTER.
Router
Receives data in the form of packets and forwards them to their destination which is often another router.
Client server network
One or more servers provide services to many client machines.
The most common way to set up a network
Peer to peer
All computers are equal, each serves the needs if the user.
Protocol
Set of rules which covers data communications
TCP/IP
Transmission protocol/ internet protocol. Has become the de facto standard for data transmission over the internet
Hosts
Computer systems which are accessed remotely and hold data or other facilities such as web servers
Packets
Collections of data forming part of a message
Packet switching
Packets from one message may take different routes according to availability and traffic. This increases efficiency
DNS
Domain name system. It translates domain names into IP addresses
IP address
A 32 bit number.
Static- permanently allocated to a device
Dynamic- changing, a computer will not always have the same address
MAC address
Media access control, unique number stored in each NIC so it can identify a device on a network. Usually given as 6 pairs of Hexadecimal numbers
Connections between devices on most LANs are made with…
Copper cable, usually known as UTP ( unshielded twisted pair)
For longer distances, fibre optic cable is used.
Hubs
Hardware devices which connect many devices together, making them into a single network segment. They have a number of input and output ports which connect to each other
