Get Faster Access - Cable Modems

Cable Modems

By Les Freed and Frank J. Derfler, Jr
PC Magazine

April 22, 1999

For about $20 more per month per PC than a typical V.90 modem ISP connection, cable modems yielded 13 to 29 times the performance of V.90 on our throughput tests. When you measure dollars spent per Mbps performance, cable modem service comes out ahead of DSL and is available to many more users today. Cable modem availability is still very spotty, however, and because many businesses don't have cable television installed in their buildings, cable modems, which use one or more spare television channels of an upgraded cable TV infrastructure, are primarily a solution for residential users.

Cable modem service is provided by a partnership between national cable Internet access providers and local cable television providers. Nationally, @Home and Road Runner dominate the market, but we also tested services from MediaOne and Optimum Online. TCI, which is planning a merger with AT&T, owns 40 percent of @Home. Media giant Time Warner jointly owns Road Runner with Compaq Computer Corp., MediaOne Group, and Microsoft Corp. These corporations supply technical know-how, a fast Internet backbone connection, and marketing and billing assistance to hundreds of local cable television operators nationwide. They also provide specialized content and their own Web portals to end users. In almost all cases, your cable modem connection service is also your ISP.

All of the homes in a given neighborhood share a single cable much the way PCs share an Ethernet LAN connection. Several neighborhood cables connect to a cable access unit (CAU), which combines signals from the neighborhood cables into a single signal. In turn, the CAU connects via a high-speed fiber-optic line to the cable company's main switching center housing the routers and providing the on-ramp to the Internet.

Today, there are two types of cable modems. Two-way hybrid fiber-coaxial (HFC) modems can theoretically achieve download speeds in the 3-Mbps to 10-Mbps range with upload speeds of around 128 Kbps to 10 Mbps. One-way coaxial modems average a 2-Mbps download speed and require a dial-up modem for the upload of data. A few providers still use the one-way coaxial technology, but most have switched over to HFC.

Most cable modems connect to your PC via an Ethernet connection, so the cable company's installer must open your PC and install an Ethernet card if you don't already have one. Sometimes the installation fee includes the modem and the Ethernet card, but you may have to buy or rent a cable modem from the cable company. Cable-modem hardware vendors include Cisco, General Instruments, Motorola, Samsung, and 3Com.

Coming to a Store Near You

Until this year, a lack of standards locked both the service provider and end users into a single-vendor solution. A new industry standard called DOCSIS (Data Over Cable Service Internet Specification) was ratified last spring, and all of the major cable modem vendors intend to deliver DOCSIS-compliant modems in by summer of 1999.

In the few areas where DOCSIS modems are currently available, you can purchase a cable modem at a local computer store for $150 to $350, sign up for the service either at the store or over the phone, and install the cable modem yourself -- assuming you already have cable TV service. We expect this to become the norm over time, especially as USB-connected cable modems become more common, making installation of an Ethernet card unnecessary. For now, the local cable company usually sends an installer to your house to set up your cable modem service. You can receive cable modem and cable TV service on the same cable, so established cable TV subscribers usually don't need any additional inside wiring to connect a cable modem. Some cable providers give established cable TV subscribers a $10-per-month discount.

Each time you turn on your PC, the cable modem automatically establishes a connection to the Internet. Just launch the same browser or e-mail application you would use for dial-up access. This high-speed, dedicated connection changes the way you think about the Web.

You won't hesitate downloading a game demo or new browser software. Since you don't have to wait 20 to 30 seconds for a connection, checking local traffic, weather, or sports scores online becomes much more practical. Work-at-home users will discover that a VPN running over a cable modem gives them the same access network resources and e-mail as their office-bound colleagues.

But though cable modems can provide stunning connect speeds, the service has a few caveats you should be aware of -- namely slowdowns, bandwidth congestion, and lack of support for LANs.

Although your provider possesses an incredibly fast connection to the Internet, there can be times when the ISP-to-Internet link can reach near capacity, slowing your connection to a crawl.

If you have a home or small business LAN, your cable company may refuse to provide service. Home LANs can be difficult to troubleshoot, and some cable companies don't want the responsibility and added support burden. If you can get service for your home network at all, you may have to pay an extra installation fee and monthly service charge for sharing the cable connection.

What We Found

We tested three leading cable modem services in seven locations: @Home in the Fremont, California, and Sarasota, Florida; MediaOne Express in Atlanta, in two suburban Boston locations, and in a Chicago suburb; and Optimum Online in Westport, Connecticut (New York City metropolitan area). Our reviewers welcomed the high-speed, always-on Internet access their cable modem provided, coupled with free Web-site hosting up to 5MB, and e-mail addresses (three each from @Home and four from Optimum Online). But unlike our DSL reviewers, several complained about slow technical support and customer service.

Our MediaOne and Optimum Online reviewers found out about cable modem service through advertisements and direct-mail pieces. The @Home reviewer in Fremont had to call @Home several times to find out that the service was available. Once our reviewers placed their orders, it took anywhere from several days to two weeks to get cable modem service installed. @Home refused to install a cable modem in our Fremont, California, reviewer's PC, claiming it was too far from the cable entry into his house. But he managed to get connected by going out and buying his own 50-foot CAT 5 cable.

Installation for one of our metropolitan Boston reviewers took 3 hours because of compatibility difficulties with a 3Com EtherLink II network interface card. In Atlanta, a special MediaOne multidwelling task force had to jury-rig a new line down the outside wall of our reviewer's building, because the cable had been disconnected at the faceplate in his wall to prevent tenants from stealing cable TV. But our Sarasota-based @Home reviewer had a painless 1-hour installation within a few days of placing his order.

The Fremont, California, installation was divided between @Home and TCI, so our reviewer had two installation bills to pay. Conveniently, MediaOne takes care of the entire installation process, resulting in one installation bill. Each ISP reviewed offers a portal that displays customized information for the user's location. One reviewer in the Boston area leaves the computer on all the time so he can quickly check traffic cams to see what his morning commute has in store for him.

All services reviewed had some glitches. Many found slower speeds during the peak evening hours. Our Optimum Online reviewer needed to replace his modem after a year (he was already connected prior to our testing). Our reviewer in Fremont bypasses the @Home proxy server and has set up his own DNS server because @Home's crashes frequently.

There were occasions when reviewers had technical problems and had to call a support line. In one instance, the San Francisco @Home reviewer stayed on hold with technical support for almost 40 minutes, only to be told that he would have to wait a week for a technician to come to his house. Our MediaOne reviewers also said that they had long hold times but felt their problems were resolved once they talked to a human being. Generally, despite concerns about customer support, our reviewers found cable modem service to be a bargain.