This paper introduces the structure of Transport Multi-Protocol Label Switching(T-MPLS) over Optical Transport Networks(OTN) and analyses the types of algorithms for the problems involved in the T-MPLS-based Routing and Wavelength Assignment(RWA).Then
it divides them into two sub-problems
concerning routing and wavelength assignment respectively
and studies them in respect of supporting traffic engineering
multi-domain
multicast and Diff-Serv on the basis of the characteristics of T-MPLS technology.