1.5Mbps is the maximum speed currently offered by most broadband sellers in Australia, due to their dependence on Telstra's wholesale ADSL1 services, but Optus' Web site had up until recently boasted that its ongoing AU$150 million infrastructure rollout would deliver "speeds of up to 20,000 kbps [20Mbps] for customers using an ADSL2+ modem and up to 8,000 kbps [8Mbps] for customers using ADSL modems."
It now states: "With Optus DSL Direct you can experience download speeds of up to 1500 kbps depending on your physical distance to your local phone exchange and the type of modem you are using."
"Your actual download speeds may vary due to other factors including the configuration of your modem and computer hardware or software equipment, the quality of your phone line, which Web sites you download from, external factors or if you have exceeded your monthly data allowance."
Telstra's existing ADSL1 services are also theoretically capable of reaching 8,000 kbps, but Telstra has said the speed is limited so the telco could guarantee all customers in Australia that base speed regardless of how far they lived away from one of Telstra's telephone exchanges.
Optus' ADSL infrastructure is likely in the short-term to include elements of its existing ADSL1 hardware as well as new DSL Access Multiplexers (DSLAMs) understood to be based on the ADSL2+ standard, and being rolled out to a planned 340 telephone exchanges nation-wide, with 100 due to be completed by April next year.
Optus' speed limits may not look that attractive to a marketplace which has for some time seen some Internet Service Providers like Internode and Adam Internet offering ADSL2+ at up to 24Mbit/s, however the new infrastructure will still allow Optus to make a better profit margin on selling ADSL services than it would if it continued to resell Telstra's wholesale offering.
In addition to the Web site change, sources indicated Optus has recently contacted existing customers which it had planned to move onto the new infrastructure, making them aware of the newly downgraded speeds.
ZDNet Australia understands those letters came after Optus had earlier contacted the same customers, touting the future 20Mbps speeds as an advantage of the new infrastructure.
"This site is intended for existing Optus home phone and DSL customers who have received a letter advising that their services are scheduled to be switched over to Optus Direct," states the Optus Web site.
An Optus spokesperson on Thursday night confirmed the move to reduce advertised speeds and the fact a letter outlining the new maximum had been sent to customers.
"Optus is currently in business readiness testing for its network rollout," they said in a statement e-mailed to ZDNet Australia. "For now, we will be offering speeds of up to 1.5 Mbps."
"We will continue to develop our product propositions as we go to market. As we carry out our initial migration of customers to the new network and finalise our product offering, we will continue to test and develop our offers."
"Only a small group of customers received a letter stating speeds up to 20Mbps. We are in ongoing communication with our customers."