On Fri, Jul 18, 1997 at 06:44:21PM -0400, Robert E. Seastrom wrote:

Am I the only one who's a cables and switches weenie enough to know that the telco's _already do this_? Large numbers of local multi-pair ^^^^^^^^^^^^^^^^ trunking cables are pressurized with nitrogen, and they put pressure drop alarms on them, so they know if one takes a hit.

pressurized nitrogen is usually done to keep moisture out, not so that they can monitor pressure loss. pressure loss in a fed, very long, pipe is an extremely local phenomenon anyway. i think there are spooks at some black agencies that monitor against tapping this way. but in practice, nitrogen pressurization is only done for copper.

Yes. I know. ;-) I'm told they really do pressure loss monitor the local stuff, though, even if more for dryness purposes than cable-break. Cheers, -- jra -- Jay R. Ashworth jra@baylink.com Member of the Technical Staff Unsolicited Commercial Emailers Sued The Suncoast Freenet "People propose, science studies, technology Tampa Bay, Florida conforms." -- Dr. Don Norman +1 813 790 7592