ADSL Max

ADSL Max is supplied by BT Wholesale to the ISPs and is available on most BT exchanges. ADSL Max is rate adaptive: what rate you get depends on the quality of your line and distance from the exchange. During the first 10 days of service, your modem will SYNC with your exchange at different rates, the lowest of which is set as the maximun stable rate. Fault threasholds are 70% of this rate.

Speed

Maximum download speeds are available within 2 km of the exchange after which speed drops over distance. Maximum upload speeds are not dependant on download speeds and only start dropping over 4 km from the exchange.

Increased upload speeds make ADSL Max particularly suitable for VoIP.

While 8 Mbit/s is the advertised download speed for ADSL Max the average is nearer 5.5 Mbit/s. BTW's SLA stipulates 400K and 800K (MAX and MAX Premium). The cheaper ISPs oversubscribe their network capacity, mixing business with residential traffic, which decreases available speed. Before you buy, ask your ISP what end-to-end throughput speeds they guarantee.

Stability

The higher the speed, the lower the stability. By running at lower speeds, fewer data packets are corrupted which helps to improve stability.

By setting the connection to operate at lower speeds, businesses will benefit from a higher bandwidth than on the fixed rate products without the re-syncing of the line and associated loss in service.
 

ADSL Max Options offer stability over speed without regular re-syncing.