Interesting addresses: http://www.trendcomms.com/multimedia/training/broadband%20networks/web/main/Copper/CoverCopper.html --------------------------------- Visi Shark description (measurement device): http://documents.exfo.com/specsheets/CableSHARKP3-ang.pdf http://www.trinstruments.cz/produkty/telekomunikacni/testery-pristupovych-siti/testery-xdsl/cableshark-p3.html ---------------------------------