POTS (plain old telephone service) is based on the flow of direct current through the loop. When you pick up the receiver current flows from the telephone company CO Switch through your set and back to the CO Switch. This flow of current signals the Switch that youre off hook and ready to make a call.
Unfortunately, when water gets into a telephone cable, it can cause the same flow of current as going off hook. This is known as a light short. This condition will eventually cause the Switch to time out and disconnect dial-tone, hence a dead line.
The ADSL signal, on the other hand, is often unaffected by a light short and as such, the ADSL service will continue to function.
by Splitpair edited by KeysCapt
last modified: 2004-01-31 11:16:57