What
is ADSL/Broadband?
What are the key benefits of Broadband
for me?
What are the key benefits of Broadband
based services for Business?
How fast is it?
Who are our Broadband based services
aimed at?
What can Broadband be used for?
When will I be able to have Broadband
installed?
How have BT chosen which exchanges
get Broadband enabled first?
What do I need in order to be Broadband
serviceable?
Are there any Service Constraints
I should be aware of?
What services on my line are incompatible
with Broadband?
How does Broadband work?
Is my fax compatible with an Broadband
set-up?
Will Broadband affect my normal
telephone connection?
Will telephone calls be charged separately?
Can customers keep an existing telephone
number?
Who is responsible for billing?
Will all BT Select services be supported?
Will Broadband affect my burglar or
security alarm system?
What computer equipment do I need?
Can you tell me more about the line
testing and validation?
What is the minimum contract period?
If I move premises what will happen
to my Broadband connection?
Who do I report faults to?
Is it dangerous to be permanently attached
to the Internet?
Which IP services are compatible with
Broadband?
Can you explain how the contention
ratios work?
Do Broadband services work with non-BT
PSTN lines?
What standard does BT's Broadband modem
adhere to?
Will BT be blocking any TCP port numbers?
FAQ Disclaimer
Broadband ADSL, or Asymmetric Digital Subscriber Line technology
is a means of transmitting digital information at high bandwidth down
existing copper telephone cable. It is permanently 'switched on',
unlike normal dial up access and is asymmetric in that it uses most
of the available bandwidth downstream. This makes it particularly
suitable for applications where customers expect to receive more data
than they transmit such as for Web browsing, use of corporate intranets,
and reception of digital audio-visual material. The technology also
supports analogue connection on the same line, which enables voice
or fax calls to be made simultaneously.
» top
Firstly, the Speed. Broadband provides high-speed digital
access - e.g. potentially 10 to 40 times faster than today's typical
modems. It’s Always On. You will no longer have to waste valuable
time obtaining a dial-up connection to your Internet Service Provider
or Corporate Intranet It’s Flexible. It does not affect the
normal telephone, so you can make and receive telephone calls or faxes
whilst you’re online.
» top
Broadband based services will allow SME's and Corporate's
to:
* Take full advantage of broadband capabilities.
* Offer innovative services to your end user base.
* Extend the reach of your Intranet to encompass your remote teleworkers
and satellite offices.
* Manage and predict your costs with the flat rate charging scheme
» top
Typical rates for Broadband are shown in the table below. Downstream
speed Upstream speed Up to 500 kbit/s Up to 250 kbit/s Up to 1 mbit/s
Up to 250 kbit/s Up to 2 mbit/s Up to 250 kbit/s This is between 10
to 40 times faster than today's typical modems.
» top
Our services are aimed at a wide range of consumers. Corporate business
users will be able to provide their teleworkers or satellite offices
with remote access to the corporate network, whilst home users will
be able to take advantage of the incredible download speeds to view
digital media on the Web, such as movies, music and similar bandwidth
hungry applications.
» top
Broadband's higher potential bandwidth has the potential to enhance
access to existing services and applications and stimulate the development
of new ones: Internet access The
access speeds available with Broadband available make it practical
for web sites to carry more multi-media rich information such as embedded
video clips, animations and good quality audio - significantly enhancing
the online experience Intranet access
Fast access to the Intranet makes teleworking an attractive option
- which in turn can bring benefits to both the organisation and the
individual TV based services Broadband
can be used to deliver interactive applications to the TV, such as
real time video and audio, home shopping and home banking.
Broadband will be the catalyst for a wealth of new information, education
and entertainment services
» top
Broadband is dependent upon BT's roll-out schedule for Broadband
serviceability of your geographical area.
» top
BT have chosen a number of criteria to establish which exchanges should
be provisioned for Broadband first. These included demand for bandwidth
and where the early adopters of these services are most likely to
be located.
» top
There are a number of factors that will determine whether you will
be able to take advantage of Broadband. These
include: That you are a BT subscriber. You must have a valid
contract for the use of a BT analogue direct exchange line forming
part of the BT network over which the Broadband service will be provided.
Note that if you rent your premises, you must have a valid contract
for a BT or Calls & Access provided PSTN line. It is not suitable
that the contract be held with your landlord rather than yourself.
Whether BT has upgraded your telephone exchange to Broadband technology,
and whether you are located within a specified distance from the exchange.
That you are aware of the installation procedure and requirements
in terms of equipment as well as location. That there are no incompatible
services on your PSTN line. That you have sufficient mains power sockets
for the BT NTE (Network Terminating Equipment
) » top
The transmission performance of some local loops will mean
that it is technically impractical to deliver Broadband service to
all end users with a particular serviceable area. BT reserves the
right to refuse Broadband installation even if you are situated in
a serviceable area.
» top
ADSL service is not compatible with these BT services: Subscriber
private metering 30k loop Private circuits Red ABC, RedCare, Meterpulse
facility, PBX lines. It is only possible to provide a single broadband
service over a single BT or a Call & Access PSTN exchange line.
» top
ADSL operates over a normal telephone line. This means that
there is no need to dig up any roads to replace cable and install
it. The Broadband signal is carried by two Broadband modems - one
in the end user's premises and one in the local exchange. These Broadband
modems are designed to exploit the physical transmission capabilities
of the copper line to the maximum extent. The resultant ‘broadband’
medium is used to achieve much higher data rates than were previously
possible. Two 'splitters' (filters), one in your premises and one
in the BT exchange, separate the telephony signal from the Broadband
signal. This means that telephone calls can be made at the same time
that data is being sent or received (i.e. a customer can surf the
Internet and still make telephone and fax calls concurrently).
» top
It is not guaranteed that your existing fax machine will work after
you have installed ADSL. Please check with the fax machine manufacturer/vendor
to check Broadband compatibility.
» top
You may notice a slight change to how your telephone sounds after
you have ADSL installed. This is normal for ADSL lines and is not
a fault. Any standard modems operating on your PSTN line (standard
telephone, not the Broadband line) may operate at a reduced speed
after Broadband installation
. » top
Yes. Normal telephone rental and call charges will still apply.
» top
Existing BT PSTN numbers will be unaffected; most end users will be
able to keep their existing telephone number.
» top
You will make payment arrangements with us for your Broadband service.
If you have any queries about your Broadband account you should contact
us and not BT. The price, billing and payment for your standard BT
telephony service will remain unchanged and BT’s responsibility.
» top
Yes, all Select Services can be supported on the PSTN line,
including Call Waiting, Call Return and Caller Display.
» top
Installation of Broadband may adversely affect security or
burglar alarm systems that use your PSTN telephone line and fail to
operate correctly. You should check with your suppliers for compatibility
of your system before arranging for Broadband installation.
» top
The service supports most protocols including Telnet, SMTP,
HTTP, FTP, TFTP, VDO, RealAudio, Cu-SeeMe, QUAKE (2.8.0). ADSL will
also support instant messaging and communication programs such as
NetMeeting, ICQ or Microsoft Messenger. Some of the advanced functions
of these programs, such as video conferencing or file sharing, will
not operate behind a firewall or Network Address Translation (NAT)
without some technical configuration, or possibly not at all. If you
have any questions, consult the user Help for the specific program.
» top
The equipment required and minimum specification of the PC depends
upon which installation you are having, USB or Ethernet version. For
the Broadband Home and ADSL NetStart USB installation, you will need
the following: A PC with the minimum specification
of: Windows 98,ME, 2000 or XP operating systems. A spare USB
port is required (if you are not sure about this, please see your
PC supplier, as the broadband modem uses USB to connect to your PC
). A 4-speed CD ROM drive, 200Mhz Pentium processor or above, 32 Mb
RAM or higher, Video card/display capable of 800x600 pixels, 256 colour
SVGA monitor, 16 bit sound card and a minimum of 150 MB free hard
drive space. For the Ethernet multi-user modem/router installation,
you will need the following: A PC with
the minimum specification of: Network Interface Card (10BaseT
Ethernet port) TCP/IP communications stack, Netscape 4 or IE 4 or
above must be loaded onto at least one of the PCs connected to the
service. The browser must be JavaScript enabled. Other specifications
will depend upon the applications you want to use with your Broadband
service and the operating system you are using. For basic Internet
browsing this should be at least: Pentium 166Mhz, MMX processor or
above, 32Mb RAM or above, a minimum of 150MB available hard disk space,
SVGA or higher rated monitor, Video card/display capable of 800x600,
256 colours Win 98,ME,2000,XP or Windows NT. A 4-speed CD ROM player,
16 bit sound card, Mouse or other pointing device. If you wish to
use Apple MacIntosh on your network, the machine should conform to
the following specification:
PowerPC 601 or equivalent 32MB System Memory, 2-speed CD ROM player,
Video driver and display capable of 800 x 600 256 colours, 100MB free
space on hard drive, OS8.1 or higher Open Transport 1.3 Networking
Software, 10baseT Network Adapter with an RJ45 connector. You will
also need appropriate lengths of Ethernet cable to connect your PCs
to the Broadband router/hub. Note that a length of 100 meters must
not be exceeded between the PC and hub.
» top
After initial ordering, BT engineers will make preliminary
tests on your line to make sure that you are Broadband serviceable.
If the tests conducted on your line show that BT are unable to install
ADSL at your location, you will be told the reason for this. Some
examples of situations may be line quality, distance from the exchange,
incorrect information being supplied upon application etc.
» top
There is a 3 month minimum contract period. You should however contact
us rather than BT if you have any queries.
» top
Your contract with BT and ourselves is for your specific location
and subject to a minimum period. This minimum subscription period
would remain payable if you move location whether or not your new
location is ADSL serviceable. If you require Broadband at the new
premises then you should make arrangements for a new installation
and your old contract will be replaced by a new one
» top
You should report faults to us and not BT in the first instance.
The only exception to this is if the fault affects only telephony
services.
» top
Any computer that is connected using Broadband to the Internet
is exposed to the same security risks as a dial-up user, however since
ADSL users are typically connected to the network for longer periods
of time (always on) this risk is potentially that much greater. You
should be aware of the potential of hacking attacks and the precautions
that you should take. Please read our security section. Some
examples of good security practice are: Turn off your PCs when
not in use. Turn off Windows File and Printer Sharing Install a virus
checking software product and ensure that it is maintained to the
latest version. You should provide a Firewall in the case of a sensitive
installation. You should provide encryption of data transmission for
sensitive data.
» top
The USB modem and the Ethernet router solutions have different contention
ratios set up by BT, with these values set at 50:1 and 20:1 respectively.
This means that for a Home user with a USB modem, the BT connection
at the exchange is shared with another 50 users. Whilst some degree
of performance loss will be experienced during peak periods, it is
generally accepted that few people will be downloading or uploading
data all at the exact same time. For the business user it makes sense
to go for the 20:1 business version, which will not be subject to
so much slowdown at peak periods. The two systems will be able to
co-exist on the same 'local loop' due to BT's network tunneling protocols,
each connection being given its own port on the exchange terminating
equipment.
» top
Currently the Broadband services are only available over a
BT PSTN line. A non-BT PSTN variant is being investigated.
» top
Various forms of Broadband signal modulation are possible
but the two more prevalent are: Discrete Multi-Tone (DMT), and Carrierless
Amplitude modulation Phase modulation (CAP). DMT uses interleaving
to achieve good error performance and has become the international
standard. BT evaluated both DMT and CAP modems during their extensive
trials throughout 1998 and 1999. However, their commercial Broadband
based services will use DMT. Alcatel and Fujitsu will supply these
modems.
» top
There has been some speculation
in the press regarding the supposed prospect of port blocking on the
ADSL service. The huge popularity of distributed networking programs
such as Napster, Gnutella and iMesh has led to fears of excessive
bandwidth consumption. BT have stated that they have no current plans
to restrict bandwidth use or block particular ports, although they
may review this in the future if the service is adversely affected
by flagrant bandwidth abuse.
» top
What impact will UMTS have on Broadband?
Universal Mobile Telecoms Service - UMTS is the so called the 3rd
generation mobile service. It is a mobile network whereas Broadband
runs over a fixed network. So, whilst UMTS will deliver broadband
access too, the two technologies are more likely to be complementary
rather than head-on competitors.
» top
Please note that although we endeavor to make sure that the information
included in this FAQ is up-to-date and accurate we cannot guarantee
that it is exhaustive, nor that changes won’t be made at any
time without prior notice.
About us 
