By Tim Greene

DSL service providers are in the thick of transitioning from ADSL technology to much faster ADSL2+, but it's unclear when that is going to result in new services.

According to Dell'Oro Group, ADSL2+ line cards have been shipping for less than six months and already in the last quarter they accounted for 13.6% of DSL ports shipped. And that is with the two leading DSL card vendors, Alcatel and Siemens, still not shipping ADSL2+ yet.

Since the new cards are backwards compatible to support traditional ADSL, and they cost only slightly more, over the next year or so, all ADSL line cards shipped will also support ADSL2+, Dell'Oro says.

That effectively boosts the bandwidth carriers can offer over their phone lines from 9M bit/sec over 6,000 feet of regular phone lines to 15M bit/sec over 8,000 feet. The question is what will they do with all that extra bandwidth?

Clearly they want to provide video services that require that kind of bandwidth. ADSL2+ can support three simultaneous high-quality video streams, but the providers don't have the back-end gear in place to offer video services. That means gear that can queue up and immediately deliver movies, extending fiber networks closer to customer sites and deploying ADSL2+ customer modems. These investments must still be made.

Current DSL services are mostly Internet access with some providers adding multiple lines of VoIP to the service at a premium. Because DSL was launched largely as a replacement for dial-up Internet access the price was relatively low so Internet users didn't suffer sticker shock. That probably won't be the case with ADSL2+ and video-on-demand services.

The price, whatever it is, could determine how valuable the technology will be for businesses. If it is a good deal like DSL is as a connection for telecommuters, it could gain widespread use, especially for businesses with high-bandwidth applications.

But while the ADSL2+ speeds could be attractive as an option for corporate networking, it may be some time before it is available at all, and how much it will cost is anybody's guess.