Which wavelength or channel do I order for 25G SFP28 MWDM?
The channel is chosen per link and has to match the far-end module and every MUX, DEMUX or OADM in the path. 25G SFP28 MWDM is ordered per wavelength, so supply the channel plan: two modules from the same family on different channels will not pass traffic to each other.