The invention relates to a method of and an apparatus for testing electronic signals in a network, comprising network units between which information can be exchanged by electronic data transmission through network connections. A plurality of testing components are coupled each to one or more of the...http://www.google.com.hk/patents/US6975860?utm_source=gb-gplus-share專利 US6975860 - Method of and an apparatus for testing connections in a network
