The NX4000 Transport Analyzer is a measuring instrument to evaluate performance, functionality and reliability of 40 Gbit/s high speed optical telecommunication systems and equipment that use not only SDH/SONET* but also Optical Transport Network (OTN)*, which is a strong candidate for Next generation Network (NGN).

*	SDH/SONET and OTN are high speed digital transmission schemes using an optical fiber. SDH and OTN are standardized by ITU (International Telecommunication Union). SONET is standardized by ANSI (American National Standards Institute).