What are the tests that BT carry out to determine availability?
BT will carry out tests on: • Line Length • BT need to check the length of your telephone line. The length of the cable must be less than 6km in order to be accepted for 1MB or higher speeds. Note, your premises may be physically closer to the exchange; BT only take into consideration the cable length from the exchange, which may be much further than the physical distance. • Noise • BT need to ensure your line has suitable quality for ADSL, you need noise of no more than 60db for 1MB products or 43db for 2MB products. 512K products have no noise limitation, but the line will still need to pass viability tests based upon the quality of the serving cabling to your premises. • Capacitance • Again, this is to establish line quality, to pass, this should be below 160nf. • Whoosh Test • The final test. BT tests again to ensure that everything will work correctly with the installation. This is the last point at which an installation can fail, and failure at this point is very rare.
