What is ADSL? [top]
ADSL (Asymmetric Digital Subscriber Line) is always on broadband service delivered over a standard BT PSTN analogue line. |
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What speeds does ADSL run at? [top]
our ISP offers ADSL at the following speeds:-
- Download: 512kb Upload: 256kb
- Download: 512kb Upload: 256kb
- Download: 1mb Upload: 256kb
- Download: 2mb Upload: 256kb
Please note all ADSL circuits are subject to a contention ratio (See next FAQ).
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What is a contention ratio? [top]
Contention ratio refers to the maximum number of users you could be
sharing your bandwidth with. There are 2 contention ratios in use by
our ISP, 50:1 and 20:1. If you have a 50:1 contention ratio then in
theory another 49 users could be competing for the 512kb you have. In
practice this very rarely happens and even on the slowest ADSL product
users typically see a 10x improvement over a 56k modem. |
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Why is the download speed greater than the upload speed? [top]
ADSL is Asymmetric which means it runs at different speeds for upload
and download. BT is currently trialling a SDSL (Symmetric Digital
Subscriber Line) service which runs at the same speed for both upload
and download. our ISP are currently working with BT to enable us to be
one of the first in the country to offer SDSL. |
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What type of phone line is required for ADSL service? [top]
A standard BT PSTN analogue line is required for ADSL. Certain BT
services and/or configurations are NOT compatible with ADSL, these
include:-
- PBX Switchboard
- ISDN 30(PRI)
- Surftime
- BT Data Stream
- BT Video Stream
- None BT Telephone Line
- Redcare Alarm Monitoring
- Pulse Metered Line
- Coin/Pay Phone
It is possible to convert a ISDN 2/2e or Business/Highway line into
ADSL. This does however mean that the ISDN service is lost as the line
has to be converted back to a single analogue line. Certain fax
machines will interfere with the ADSL signal so it is not recommended
that you use a fax line for ADSL. |
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What is the minimum contract term for ADSL? [top]
The minimum term is 6 months and there is a 1 month notice period to cancel.
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What is NAT/No-NAT? [top]
NAT (Network Address Translation) is a technology that allows you to
share a single IP address assigned by a ISP among a number of computers
on a LAN. Most ADSL hardware supports NAT out of the box.N0-NAT
means that instead of having a single IP address to share you get a
subnet of 8 or 16 IP's that are routable and can be assigned to your
computers. Please note that because a subnet is assigned it means you
do not have access to all the 8 or 16 IP addresses. On a 8 IP
connection 5 IP addresses are available to you and on a 16 IP
connection 13 IP addresses are available. This is because a IP is
reserved for the network address, broadcast address and router
respectively. |
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Do you assign fixed IP addresses? [top]
Yes, all our ISP's ADSL accounts come with fixed IP addresses on both NAT and No-NAT.
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What is a microfilter? [top]
A microfilter, sometimes referred to as a 'spliiter', is an adapter
that plugs into the telephone socket the ADSL service is provided on.
The microfilter seperates the ADSL signal from the voice signal. You
plug your phone and your ADSL hardware into the microfilter and the
microfilter into the BT phone socket. |
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| If you need any more information please contact support@Onsite-it.co.uk |
