Jargon Buster
ADSL
Asynchronous digital subscriber line
APC
APC stands for “American Power Company” - APC makes the high quality power distribution unit that we use at 4D allowing for real-time power monitoring and remote control of outlets for reboots.
AS Number (“AS”)
An AS is a group of IP networks managed by one or more network operator(s) that has a single and clearly defined external routing policy. Exterior routing protocols, such as BGP, are used to exchange routing information between AS’s. The more networks the traffic has to traverse to reach its destination the longer the ‘AS Path’ will be and, generally, the higher the latency. The 4D Data Centres AS number is ‘AS 31463’. You can find out more about our network from the looking glass and at this link.
ASP
Application service provider
Backhaul
Rack connections function like site-to-site connections but stretch between datacentres.
In a traditional telecommunications network the backhaul portion of the network comprises the intermediate links between the core network, or backbone, of the network and the small subnetworks at the "edge" of the entire hierarchical network.
For example, while mobile phones communicating with a single mast represent a local subnetwork, the connection between the mast and the rest of the world begins with a backhaul link to the core of the telephone company's network (via a point of presence).
Visualizing the entire hierarchical network as a human skeleton, the core network would represent the spine, the backhaul links would be the limbs, the edge networks would be the hands and feet, and the individual links within those edge networks would be the fingers and toes.
BPS
Bits per second
Carrier neutral
Clients can choose their internet service provider and are not tied to taking connectivity from a provider which also owns the data centre.
CGI
Common gateway interface
CRAC units
Computer room air conditioning unit
DHCP
Dynamic host configuration protocol
DHTML
Dynamic hypertext mark-up language
DNS
Domain name system
DR
Disaster recovery
DSL
Digital subscriber line (or loop)
EASTER EGG
A virtual Easter egg is an intentional hidden message, in-joke or feature in a work such as a computer program, web page, video game, movie, book or crossword. The term was coined—according to Warren Robinett—by Atari after they were pointed to the secret message left by Robinett in the game Adventure. Example
FM-200
A waterless (gas) fire-suppression system
FTP
File transfer protocol
GPRS
General packet radio service
GSM
Global system for mobile communications
GUI
Graphical user interface
HTML
Hypertext mark-up language
HVAC
Heating, ventilation and air conditioning
ICANN
Internet corporation for assigned names and numbers
IMAP
Internet message access protocol
IP
Internet protocol
ISDN
Integrated services digital network
ISP
Internet service provider
KBPS
Kilobits per second
LAN
Local area network
LINX
London internet exchange
Looking Glass
A network looking glass provides the ability for a third party to view expanded information relating to backbone routing of our network. This covers ping, traceroute and BGP information showing the number of routes as well as information on whether specific routes are available from the 4D network. This can be useful for diagnosing network problems and for more general information on how a network is performing.
Mbps
Mega-bits per second
N or N+ 1 etc
N represents one standard part / machine. N+1 means we have the part or machine plus one set of ‘spares’ in layman’s terms should the original break. In other words redundancy is built into the infrastructure so that if one component fails, continuous operation is maintained and there is a hot standby (the “1”) if another component fails.
NAP
Network access point
NAS
Network-attached storage allows you to store and back-up files via our fast fibre network. As NAS is a disk based system, rather than tape, it gives you instant access to any backed up files as well as fast backup / recovery times.
NSI
National Security Inspectorate
PDA
Personal digital assistant
PHP
Hypertext processor
Physically diverse fibre
Two or more fibre connections along separate routes in the ground with separate building access points.
POP
Point of presence
POP3
Post office protocol (latest version)
PPP
Point-to-point protocol
PUE
Power usage effectiveness - PUE is calculated by dividing the total amount of power a data centre consumes by that which is used by the IT equipment. A PUE score of around 2 for a data centre would be considered ‘average’, while a PUE of 1.5 is deemed ‘efficient’ and anything below this is difficult to achieve; a few facilities are now operating at 1.1 – 1.4 by using very efficient cooling methods.
QOS
Quality of service
RSS
Really simple syndication or rich site summary
SIA
Security Industry Authority
SLA
Service level agreement. The SLA outlines the level of service you can expect from 4D along with specifying the levels of availability that can be expected from services such as power or network connectivity and the responsiveness to reported faults.
SMTP
Simple mail transport protocol
SQL
Structured query language
SSL
Secure sockets layer
TCP
Transmission control protocol
TCP / IP
Transmission control protocol / Internet protocol
Tier I:
composed of a single path for power and cooling distribution, without redundant components, providing 99.671% availability.
Tier II:
composed of a single path for power and cooling distribution, with redundant components, providing 99.741% availability
Tier III:
composed of multiple active power and cooling distribution paths, but only one path active, has redundant components, and is concurrently maintainable, providing 99.982% availability.
Tier IV:
composed of multiple active power and cooling distribution paths, has redundant components, and is fault tolerant, providing 99.995% availability.
TLD
Top-level domain
UPS
Uninterruptable power supply for ensuring availability during brown/black outs as well as avoiding damage to hosted equipment by smoothing surges/spikes in the main electricity supply. A UPS works in a similar way to a laptop battery. If your laptop is fully charged and you pull out the power supply, the computer stays on because the technical load (the screen, CPU, memory etc.) is actually running off the battery. The same is true of our UPS, except on a much bigger (and complex) scale.
VBNS
Very high speed backbone network service
VESDA
“Very Early Smoke Detection Apparatus” a smoke-detection brand using lasers to constantly sample the air for smoke particles.
VISP
Virtual internet service provider
VM
Virtual machine
VOIP
Voice over IP
VPN
Virtual private network
W3C
World wide web consortium
WAP
Wireless application protocol
WASP
Wireless application service provider
WEP
Wired equivalent privacy
WI-FI
Wireless fidelity
WWW
World wide web
XML
Extensible mark-up language
XSL
Extensible stylesheet language
