Networking and Internet Flashcards
Protocol
A standard set of rules that allows devices to communicate successfully. E.g. TCP
Specify data formats. eg linking computer to a printer
Standard
Guidelines to ensure that manufacturers of network equipment create product that are compatible with other manufacturers’ products. E.g. RJ45 connector
Protocol Stack
A group of protocols which allows all devices on a network (and internet) to communicate irrespectively of the equipment used.
HTTP
Hyper text Transfer protocol:
Transferring (request and view)multimedia web
pages over the internet - Application Layer
FTP
File transfer protocol:
Copying a file from one location to another over the
internet - Application Layer
SMTP
Simple mail Transfer protocol:
Mail applications typically use SMTP only for sending
email messages - Application layer
IMAP
Internet Message Access protocol:
Transferring emails between computer systems via
the internet - Application layer
DHCP
Dynamic Host Configuration Protocol:
a client/server protocol that automatically provides
an Internet Protocol (IP) host with its IP address
and default gateway - Application layer
UDP
User Datagram protocol:
Sending datagrams across a network with very
few error recovery services.- Transport layer
TCP
Transmission Control protocol:
Error control protocol defined for high-speed
communications within a network. - Transport layer
Handshaking
The exchange of signals between devices to establish their readiness to communicate
Internet
Global network of interconnected networks that use IP addresses and TCP/IP
Intranet
A private network within an organization for employees. It uses internet technology, e.g. browsers & hyperlinks to allow communication.
Extranet
A website that allows external stakeholders to access information usually by the use of usernames and passwords
World Wide Web
A collection of documents and other resources identified by URLs, interlinked by hypertext links, and accessed via the Internet
WAN
A set of links that connect geographically remote computers and local area networks
LAN
Group of devices, computers, printers, scanners under the control of one organization in a small geographic area
Gateway
Device that connects networks that use different protocols
Server
A software process that provides a service requested by a client
Client
A software process that requests and uses the services provided by a server
MAC
address
A media access control address also called physical address, is a unique identifier assigned to network interfaces for communications on the physical network segment.
IP (v4) address
A unique address that identifies a device on a network. 32 bits e.g. 192.168.168.5
IP Header
- Version - IPv4 / 6
- Total length - typically 64 bytes and 1500 bytes
- Identification - unique packet sequence number
- TTL - (Time to Live) decremented by 1 by each router until 0 when it is dropped.
- Protocol - The protocol of the transport layer
- Header checksum - Calculated at each hop to make sure that the header was not corrupted.
- Source IP address
- Destination IP address
Switch
Networking device that connects devices together on a (in one network) network using the MAC address, by using packet switching to receive, process and forward
data to the destination device.
Router
device that connects networks that use the same protocol. It forwards packets by using the IP address.
Holds addresses of other devices in network so data sent to correct destination
TCP/IP
A set of working practices that allow all internet users to communicate with each other whatever their equipment
Application Layer
Governs how two applications work with each other
Transport Layer
Establishes the connection between applications (end
points) and governs aspects of end-to end communication between two end hosts. Splits message
up in packets, adds error checking details and port
numbers.
Network Layer
Governs the transmission of packets across the internet –
typically by sending them through several routers along
the route. IP address of sender and receiver are added
to the packet.
Data Link Layer
Governs the transmission of frames across a single
network and is responsible for creating the frames that
move across the network.
Physical Layer
Governs transmission between adjacent devices
connected by a transmission medium (e.g. electrical
signals)
Datagram/packet
Group of bits containing, source/destination address, error control bits, control
bits and data payload
Socket
combination of a host IP address and a port number. It forms a bidirectional communication path between the end processes or applications. e.g. 192.168.168.2:1045
Port
an address for a software process e.g. 80
Encapsulation
Inclusion of one data structure within another e.g. contents of data payload are hidden from the TCP layer data that packages it
DNS
Domain Name System: The Internet’s system for converting alphabetic names into numeric IP addresses. For example, when a Web address (URL) is typed into a browser, DNS servers return the IP address of the Web server associated with that domain name
