21CN Acronyms

Broadband abbreviations and meanings

Like most other large corporations, BT love their acronyms. With 21CN they have really outdone themselves. Below is a list of many of the common acronyms you may come across when reading about 21CN.

21CN - 21st Century Network
BT's next generation network, which is being rolled out between 2007 and 2012.
ADSL - Asymmetric Digital Subscriber Line
This is the most common way in which broadband is delivered in the UK.
ADSl2+ - Asymmetric Digital Subscriber Line, version 2+
A form of ADSL offering up to 24Mbps downloads, and up to 2.5Mbps upstream (for the Annex M version).
AP - Aggregation Point
The point at which broadband/voice traffic from multiple exchanges is aggregated in to a single point, ready for hand-off to a CP.
CP - Communications Provider
BT's terminoloy for an ISP
DPI - Deep Packet Inspection
The process by which a traffic analyser will look beyond the packet headers and down in to the packet payload in order to determine the type of traffic or other characteristics.
DSLAM - Digital Subscriber Line Access Multiplexer
The device installed in telephone exchanges that terminates copper pairs to provide xDSL connections. Superceded in 21CN by MSANs.
EP - Extension Path
The link between the APs and the MSILs.
EUA - End User Access
BT's terminology for the tail circuit from the exchange to the end users premises
FTTC - Fibre To The Curb
The process by which fibre optic cables are laid from the exchange to the curb (typically a street cabinet). Traditional copper connections then run from the street cabinet to the premises.
FTTP - Fibre To The Premises
Fibre optic cables delivering services directly to the premises from a local POP or telephone exchange.
IP - Internet Protocol
The most commonly used set of rules governing how information is sent over networks (not necessarily just the Internet).
ISDN - Integrated Services Digital Network
A means of transmitting voice and data at up to 64kbps per channel.
ISP - Internet Service Provider
A provider of internet access services (such as ADSL).
LLU - Local Loop Unbundling
The BT Openreach product that allows ISPs to install their own equipment in telephone exchanges and just use the copper pair to premises.
MSAN - Multi Service Access Node
A single piece of equipment installed into exchanges that can provide telephony, ISDN and xDSL all in one package.
MSIL - Multi Service Interconnect Link
A new form of Ethernet backhaul for 21CN technologies. Speeds available at up to 1Gbps at present, with 10Gbps in the pipeline.
NGN - Next Generation Network
The generic name given to a new breed to communications networks.
POP - Point of Presence
A site in which a communications provider hosts equipment for terminating connections.
QoS - Quality of Service
A measure of how "good" the service on a broadband connection is. Most QoS implementations allow you to define different priorities for different types of traffic (e.g. Web, VoIP, email)
SDSL - Symmetric Digital Subscriber Line
A DSL service in which the upstream and downstream channels operate at the same speed.
VoIP - Voice over IP
The generic name given to telephony services that communicate using IP rather than the old PSTN.
VP - Virtual Path
A virtual link of a predefined capacity carrying broadband traffic from the DSLAM in the telephone exchange back to the BT network.
WBBC - Wholesale Broadband Connect (old name)
Accronym replaced by WBC, since "WBBC" led to confusion with the BBC.
WBC - Wholesale Broadband Connect
BT's new wholesale broadband product, offering ADSL2+ and QoS services nationally.
WBCC - Wholesale Broadband Connect Converged
A combined voice and broadband product based upon WBC.
WBMC - Wholesale Broadband Managed Connect
An end-to-end version of WBC that simplifies management by handling traffic from all Aggregation Points.
WCA - Wholesale Converged Access (old name)
Product renamed and accronym subsequently changed to WBCC.