IEC 62343-5-2:2018 describes the measurement methods of dynamic crosstalk during port switching for 1 x N fixed-grid wavelength selective switches (WSSs). The objective of this document is to establish a standard test method for different-channel dynamic crosstalk and same-channel dynamic crosstalk that occur when a particular optical channel signal is switched to the specific branching port against a common port in ITU-T 50 GHz and 100 GHz fixed grid 1 x N (N = 3) WSSs.