What's Up, DOCSIS?
By Joseph Moran
A recent survey from JD Power found a majority of Internet access customers (41 percent) get it from a cable modem. (In case you're curious, 30 percent use DSL and 25 percent still use dial-up connections.) If you're one of that 41 percent, changes are afoot that may soon come to a cable modem near you.
Almost all cable systems provide Internet access through a standardized technology called DOCSIS (Data Over Cable Service Interface Specification), and most of these systems currently employ a relatively old version of the standard called DOCSIS 1.1.
Lately, however, many cable companies have begun updating their systems to support the most recent 3.0 version of DOCSIS. Among other enhancements, DOCSIS 3.0 offers the potential for much speedier Internet connections (as fast as 160 Mb/sec for downloads and 120 Mb/sec for uploads, although real-life connection speeds aren't nearly that high). DOCSIS 3.0 achieves its higher speeds by combining bandwidth from multiple channels (known as channel-bonding, but commonly referred to as wideband) into a single connection. In contrast, prior versions of DOCSIS can use only a single channel at a time.
So when can you expect to DOCSIS 3.0 to be available in your neck of the woods? If you get your cable modem service from one of the larger cable companies like Cablevision, Comcast, Cox, or Time Warner, it may be just over the horizon. That's especially true in areas that have or about to receive-superfast fiber-based services like Verizon's FiOS or AT&T's U-Verse, which generally offer far better performance than typical cable modem connections.
Comcast, the largest U.S. cable provider, seems to be moving the most aggressively toward DOCSIS 3.0. The company already has it up and running in the Twin Cities of Minneapolis and St. Paul, Minn., as well as in parts of the Northeast and much of New England (with speeds as high as 50 Mb/sec down and 10 Mb/sec up). Comcast says it plans to have DOCSIS 3.0 available to 20 percent of its customers by the end of 2008, and to its entire service area by the middle of 2010. (Comcast customers can check for DOCSIS 3.0 availability by ZIP code or sign up for e-mail notification when it arrives.)
When DOCSIS 3.0 does show up in your area, you'll need to have a DOCSIS 3.0-compatible cable modem to take advantage of the increased performance. If your cable modem doesn't support DOCSIS 3.0 which it likely doesn't your cable company will provide an upgraded unit provided you rent your cable modem from them.
What should do if you own your cable modem or are thinking of buying one? If you're in the latter category, you should hold off buying for now. Although the DOCSIS 3.0 standard was finalized more than two years ago, the cable modems available for retail sale like the ones most people currently rent from their cable companies support only up to DOCSIS 2.0 (and best as I can tell, aren't upgradable). Once DOCSIS 3.0 service becomes more widespread, compatible cable modems should start hitting shelves. When they do, you'll want to consider the purchase price relative to the typical $3 monthly rental fee to make sure buying one is cost-effective. (And it very well may be.)
If you already own a cable modem and don't need a faster connection, you won't necessarily need to get rid of your existing hardware because it will continue to work after DOCSIS 3.0 comes to town. After all, lots of people will still have pre-DOCSIS 3.0 cable modems, and at least for the foreseeable future, cable companies will upgrade only those who sign up for the faster service.
If you do decide to take the plunge, know that the higher speeds of DOCSIS 3.0 will come with higher prices. Expect to pay more for DOCSIS 3.0-based Internet connection maybe as much as several times more than for a standard one.Joseph Moran is a regular contributor to PracticallyNetworked.
For more help, check out the PracticallyNetworked Forums.
|Home | Networking | Backgrounders | Internet Sharing | Security | HowTo | Troubleshooting | Reviews | News | About | Jobs | Tools | Forums|