Factors that affect broadband speed

Guide to ADSL line speeds
The following are how we define some of the terms used on our web site:

Advertised Speeds
This is the speed used in the description of the packages we sell, ie. ADSL Max is described as 'up to' 8Mb because the service is provided at the highest possible speed that a line can support up to the 8Mb speed.

Maximum Access Line Speed (Or 'Estimated Maximum Line Speed')
This is the maximum speed your line should be able to support. We provide this estimate (e.g. 6Mb) to you after you enter your telephone number at point of registration. This estimate will vary from house to house depending on how far you are from the local telephone exchange and the length of the wire leading to your home. This figure is provided to us by the owner of the telephone network.

Throughput Speed (Also known as 'Connection Speed')
This is the actual speed experienced when you are connected to the internet. This figure is often dependent on many factors, from the number of subscribers online at the same time to the number of people accessing the same web sites that you are. Throughput can vary from day to day or intervals within the same day.

Speed Constraints
Once connected and stable, the access line speed and throughput can be affected by a number of factors.

Access Line Speeds: 
The initial estimate provided is based on a test on your telephone number and distance calculated between your premises and the local telephone exchange. This is an estimate as there is no assurance that the cabling follows the most direct route. Hence the distance from the exchange is known as the line length.
Further implications to the line access speed (sometimes referred to as line or sync rate) will emerge if your internal telephone wiring is not optimal or long extension cables are being used. In addition, the set up and quality of hardware may impact the line rate. Hardware would include your PC speed, modems and micro filters.

Throughput: 
Being a shared network, the ADSL service we provide is optimised to the best of our abilities. There will therefore be busy times when throughput speeds seem lower due to congestion. Put simply, the sheer volume of customers using the network at the same time. There are peak times (typically 6pm to 10pm) where the network is being used by the most customers. Our fair use policy and traffic management measures aim to optimise the service for all customers at all times.

A technical issue could be responsible for a slowed throughput. This is harder to identify but would be more recognisable if you notice a degradation of service from a previous time on the same telephone line.
The customers own premises and configuration can also affect the throughput. The following are some of the most common reasons for reduced throughput:

• Interference from other devices in the home
• The type of application being used
• Internal shared services (multiple PC's / Games consoles / IPTV)
• External applications sharing your devices (peer to peer)
• Viruses and Spyware and other installed software on the PC
• Insufficient or incorrectly installed micro filters

There are other factors which can reduce the throughput speeds. IP / ATM and other overheads needed to secure the service in the network means that an 8Mb service is likely to only ever receive 7Mb of throughput at best. Other external factors include:

• Quality of the wiring from the telephone exchange to your door
• Interference / noise
• Stabilisation period (10 days from the time a MAX order is completed)
• A fault in the network profile