A USB receptacle is mateable along a predetermined direction with a special USB plug comprising an identifiable portion. The methods include downloading a set of tests through a network backbone to simulate access to the VPN from the alternate access connection and comparing the results of the test to benchmarks for the test of access to the VPN from leased lines and modems. Also, provided is an apparatus and kit for detecting the presence of toxic materials within a sample. The method may further include filling the physical isolation trench in connection with application of a multi-dielectric layer layer), a polysilicon liner andor an oxide film.