Number 194 - July 1999

Does TCI @Home Cable Modem
Also Require a Phone Line?
by Bob Thomson, Tacoma Open Group for Microcomputers
At the June meeting, Ray Mills suggested that the Downlink with a cable modem is very fast but the Uplink is relatively slow and uses the client's telephone line rather than cable. I insisted there is NO telephone link to my Cable Modem, a Motorola CyberSURFR WAVE. Was a telephone link made through my Digital cable TV box?     My cable modem connections are a coaxial cable, a power line and a USB hook up through a network device to my computer. The cable is a separate one, run to my computer room from a junction box at the front of my house, not teed off the TV cable. The line has a filter to prevent interference.     I subscribe to Digital Cable and the digital cable box on top of my TV does have a telephone line connected to it to allow ordering Pay Per View movies and having them turned on via the phone line.     I have a regular telephone modem in my computer. It is connected to my phone line.	The implication was that, somehow, the cable system was sending my uploads to the Internet through the telephone line connected to my digtal cable box, or that somehow my telephone modem was being used, even though I can talk on the phone while uploading. This uplink seems very unlikely.     Ray suggested that I disconnect the phone line. I should, then, be unable to change pages on the Internet since my keyboard commands would not be sent out. This morning I disconnected the phone line from my digital cable box on my TV and noticed no difference, changing pages and reading e-mail normally. I then disconnected the phone line from my telephone modem as well. With both phone lines disconnected the system performed normally. @Home has a RELOAD command on their Home Page which reloads it from outside your system so it is not simply one stored on your computer. The screen display is changed throughout the day and night.     Conclusion: MY TCI Cable Modem system in Tacoma does not require a telephone line in addition to the cable system. Both MY Uplinks and Downlinks are performed through the cable. Uplinks may still be slower, I don't know that answer.
Number 194 - July 1999