DSL & Modems

DSL & 56k Modems

If you get DSL service, you may find your modem performance impaired!

DSL works by sending an "out-of-band" signal on your regular phone line. 56k Modems operate in the normal voice range of a standard phone line ( ~150 - ~3500hz). DSL adds a signal at much higher frequencies. (That's why not everyone can get DSL - if your phone line is long and has load coils, they attenuate any higher frequencies; lines served by digital carrier (SLC, DLC, etc.) also cannot carry standard DSL signals.

The problem is: 56k modems are pushing the limits of a standard phone line; the out-of-band DSL signal, or the filters added on your line, can add sufficient voice-band noise to cause significantly reduced modem performance. It may affect 56k, V.34, as well as fax connections and speed.

Short of getting a second phone line that doesn't have DSL, there's not a lot you can do about this problem. The quality and effectiveness of any DSL filters is the main area where you might have some success.

If you have any information to share on this subject - success, failure, or no problems with DSL & your 56k Modem - PLEASE LET ME KNOW!