The technology of link capacity adjustment scheme (LCAS) is one of the key technologies of the next generation of MSTP solution in MAN.In this paper, it first summarizes the next generation of MSTP, then introduces the EoS network testlab and expatiates the function designing for the testlab according to the characteristic of LCAS, then particularly describes critical points of the realization. Then, it analyses the plan of the function testing and brings forword some evaluations a of the LCAS technology points based on the testing result. Finally, it gives some conclusion for the LCAS technology.