ADSL SPEED RANGES

Service Rating	Acceptable speed in Kilobytes (kilobits)
256/64kbps	17 KB/sec (138 kbps)
512/128kbps	39 KB/sec (312 kbps)
1500/256kbps	110 KB/sec (880 kbps)
8000/384kbps (Best Effort)	110 KB/sec (880 kbps)

The data rates available to a particular ADSL customer (especially 8Mb ADSL) are affected by many factors, and some by quite significant amounts. These include:

• The length of copper wire from the exchange.
• The number of, and type of, other services being used over copper pairs in the same cable by other customers.
• The configuration and line quality of the copper wire pair between the exchange and the customer’s premises.
• Electrical interference from outside sources (such as electric motors).
• The configuration of the copper wiring within the customer’s premises.
• The software configuration and application on the customer’s computer (in particular how it uses the uplink back to the exchange).
• The customer’s hardware or modem.
• The capacity of, load on, and access data rate of the destination host computer which the customer is accessing.