|
ADSL |
|
Asymmetric Digital Subscriber
Line. This is a DSL line where the
upload and download speeds differ
- typically the download speed is
faster than the upload speed. |
| ATM |
|
Asynchronous Transfer Mode - an
international standard for data
transmission in which multiple service
types (voice, video, data etc.)
are conveyed in fixed-length (53-byte)
'cells'. |
| BT
Central |
|
The name of the circuit used to
connect the ADSL broadband ISP into
the BT network - typically available
in speeds from 2Mbit/s up to 622Mbit/s |
| CAT5 |
|
Category 5 cable. |
| CBT |
|
Constant Bit Rate. |
| CHAP |
|
Challenge Handshake Authentication
Protocol. |
| CRC |
|
Cyclic Redundancy Check. |
| DACS |
|
Digital Access Carrier System. |
| DHCP |
|
Dynamic Host Configuration Protocol. |
| DNS |
|
Domain Name Server or Domain Name
System. |
| DSL |
|
Digital Subscriber Line. This
is a method of transmitting data
over standard telephone lines -
in the UK a variant called ADSL
is most common for providing broadband
access. |
| DSLAM |
|
Digital Subscriber Line Access
Multiplexer - this is the device
that connects many ADSL circuits
to the BT network by multiplexing
traffic onto one or more trunk lines.
|
| Firewall |
|
Essentially a firewall is a traffic
cop standing between two seperate
networks (usually your network and
the Internet) analysing the data
packets wishing to pass from one
network to the other. A firewall
will prevent the packets from crossing
unless they are explicitly permitted
to do so. Firewall rules can be
quite complex - usually based on
the packet source, destination and
type of traffic. |
| HTML |
|
HyperText Markup Language - web
pages are typically written in HTML.
If you are designing web pages yourself
you often have little need to actually
know the HTML language as there
are many WYSISYG (what-you-see-is-what-you-get)
web design programs like Microsoft
Frontpage, Macromedia Dreamweaver,
Adobe GoLive etc. available. |
| ISDN |
|
Integrated Services Digital Network.
ISDN is a digital dialup service
often used where broadband access
is not currently available. Typically
available in 64kbit/s single channel
or 128kbit/s dual channel (bonded)
variants. A single ISDN channel
is 'roughly' twice the speed of
a normal modem but still only a
fraction of the speed of ADSL broadband. |
| Kbit/s |
|
Kilobits per second. |
| ISDN |
|
Integrated Services Digital Network.
ISDN is a digital dialup service
often used where broadband access
is not currently available. Typically
available in 64kbit/s single channel
or 128kbit/s dual channel (bonded)
variants. |
| LCP |
|
Link Control Protocol. |
| L2TP |
|
Layer 2 Tunneling Protocol. |
| LSS |
|
Limited Service Selection - the
ability for an ADSL broadband user
to connect to multiple BT Central
communication links. |
| Mbit/s |
|
Megabits per second. |
| MSO |
|
Major Service Outage. |
| MSF |
|
Major Service Fault. |
| MTU |
|
Maximum Transmittable Unit - this
is the maximum amount (in bytes)
of data sent in each data packet
- some people experiencing lower
than expected download performance
'may' improve this by altering the
MTU - see here
for more details. |
| NAT |
|
Network Address Translation. This
is a system often used on routers
to provide access for multiple computers
on a network through one 'real'
IP addresses assigned by their ISP.
The router stores the internal 'private'
network IP address, the destination
IP address and port number in a
routing table so when data returns
the NAT can match the them up and
forward the traffic correctly. |
| NTE |
|
Network Terminating Equipment. |
| PBX |
|
Private Branch Exchange. |
| POTS |
|
Plain Old Telephone System. |
| PPP |
|
Point to Point Protocol. |
| PPPoA |
|
PPP over ATM (the standard delivery
method for ADSL servies). |
| PPPoE |
|
PPP over Ethernet. |
| PSTN |
|
Public Switched Telephone Network.
|
| PVC |
|
Permanent Virtual Circuit. |
| RADIUS |
|
Remote Authentication Dial-In
User Service. |
| RADSL |
|
Rate Adaptive Digital Subscriber
Line (also described as 'rate adaption').
This is a variant of ADSL that extends
the maximum distance from your exchange
by adjusting the upstream bandwidth
based on line quality. RADSL increases
the maximum distance supported from
3.5 to around 5.5 kilometres. This
now means that typically 90% of
people connected to an ADSL enabled
exchange can get a broadband service.
This option is only available on
the 500Kbit/s services and due to
the increased circuit length the
maximum upload speed 'may' be lower
than a normal ADSL circuit. |
| |
|
Réseaux IP Européens.
RIPE was setup to oversee the administrative
and technical co-ordination necessary
to enable the efficient operation
of a European IP network. See: www.ripe.net
for more details. We are members
of the RIPE NCC and a Local Internet
Registry. |
| SDSL |
|
Symmetric Digital Subscriber Line.
A variant of DSL where the upload
and download speeds are the same.
There are trials currently being
run for SDSL in the UK - will post
updates as we have more news! |
| SMDS |
|
Symetric Multi-Megabit Data Service. |
| TCP/IP |
|
Transmission Control Protocol/Internet
Protocol - the 'language' of the
Internet. |
| USB |
|
Universal Serial Bus - connection
type used to connect most ADSL modems
to the computer. |
| VCI |
|
Virtual Channel Identifier. |
| VOIP |
|
Voice Over IP. |
| VPI |
|
Virtual Path Identifier. |
| VPN |
|
Virtual Private Network. This
allows a secure, encrypted connection
between two points over the Internet.
|
| WAN |
|
Wide Area Network. |
| |
|
|
| Previous
page |
