Transport networks are evolving from TDM to carry packets more efficiently.
While next-generation synchronous digital hierarchy (NG-SDH) retains a key role, the latest generation of Packet Optical Transport Platforms is integrating cost effective wavelength switching, extended reach optics, connection-oriented packet standards and optical transport network/optical data units (OTN/ODU) networking.
The great diversity of network contexts results in there being no single solution that is optimum for all cases.
This paper describes the main options and their selection criteria.