Component 10 - Key Definitions Flashcards
Characteristics of networks and the importance of protocols and standards
Network protocols are sets of established rules that dictate how to format, transmit and receive data so computer network devices – from servers and routers to endpoints – can communicate regardless of the differences in their underlying infrastructures, designs or standards.
To successfully send and receive information, devices on both sides of a communication exchange must accept and follow protocol conventions. Support for network protocols can be built into software, hardware or both
The internet structure: * The TCP/IP Stack. * DNS * Protocol layering. * LANs and WANs. * Packet and circuit switching
LAN: A Local area network, usually confined to one small geographic location (e.g. a house or office). A LAN is an internal network, all devices are usually connected using switches and use dedicated equipment, meaning bandwidth is not shared with any external device or organisation.
WAN: A Wide Area Network, covers a large geographic area and usually makes use of shared telecommunications equipment meaning bandwidth is shared between multiple users.
DNS: Domain Name Server/Services, a hierarchy of public servers which are responsible for converting URL’s into IP addresses.
Protocol Layers: Protocols are complicated and therefore are usually split into different layers. Each layer will have distinct functionality and will be self contained. A Layer expects certain specific inputs and will provide specific outputs to the next layer. The advantage of layers is that they can be implemented in hardware, software or split between both. This can have significant cost savings when developing a system, or could provide significant performance gains if implemented purely in hardware. A further advantage is that each layer can be implemented, updated or developed separately without affecting the others.
Packets and Packet Switching: All data sent across a network is split into parts called packets. Packets are small, fixed size pieces of data designed to improve the reliability of data transmission. If a packet is lost on a network, the time taken to re-send it is far less significant than if an entire piece of data needs to be sent again. Furthermore, packets can be sent through different paths on a mesh network like the internet meaning they can take the most efficient/fastest path to their destination.
Network security and threats, use of firewalls, proxies and encryption. (d) Network hardware. (e) Client- server and peer to peer
Firewall:
Proxy:
Encryption: Networking Hardware: Client Server
Peer to peer
