Voice and Data Cabling

Voice & Data Cabling

Codex systems is now offering broadband access specifically designed for small and medium enterprises. At competitive prices with speeds up to 2mbs, four times as fast as existing broadband suppliers and a FREE static IP address, we believe we have the ideal package for you.


                  Static IP Addresses

                         1 IP address                                                               

                         8 IP addresses   (No NAT - 5 usable)                 

                         16 IP addresses (No Nat - 13 usable)             






What is ADSL?

ADSL (Asymmetric Digital Subscriber Line) is always on broadband service delivered over a standard BT PSTN analogue line.

What speeds does ADSL run at?

IT Helpers offer ADSL at the following speeds:-

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).


What is a contention ratio?

Contention ratio refers to the maximum number of users you could be sharing your bandwidth with. We uses the lower contention ratio of 20:1. If you have a 20:1 contention ratio then in theory another 19 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.


Why is the download speed greater than the upload speed?

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.


What type of phone line is required for ADSL service?

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



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.


What is the minimum contract term for ADSL?

The minimum term is 6 months and there is a 1 month notice period to cancel.


What payment methods are available?

You can use credit/debit card or cheque to pay the initial installation and first month/quarter charges. After that all subsequent charges are payable by direct debit.


What is NAT/No-NAT?

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.


Do you assign fixed IP addresses?

Yes, all Codex systems ADSL accounts come with one fixed IP address on both NAT and No-NAT. Additional IP addresses can be obtained. (See prices above)

Please contact us for more information via our website contact form or call us on 

Phone  : 0730 555 2727

Email   : info@ithelpers.co.uk

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We are in

Waverley House,

9 Noel St, Soho,

London,W1F 8GQ

Phone  : 0730 555 2727

E-mail  : information@codex.systems


© 2015 by codex systems. All rights reserved.