Optical transceiver module for an optical line terminal of an optical access network, comprising, - an optical transmission unit, - a first and a second optical reception unit (RX1, RX2), - an optical filter, - an optical circulator, and - an optical interface, connectable to an optical transmission link, wherein said optical transmission unit is operable to modulate an optical downstream signal, possessing a downstream wavelength, in dependence on a data signal and a measurement signal, wherein said optical circulator and said optical filter are operable in conjunction, - to provide said optical downstream signal from said optical transmission unit to said optical interface, - to receive a received optical signal from said optical interface, wherein said received optical signal comprises an optical upstream signal at an upstream wavelength, different from said downstream wavelength, and a reflected signal fraction of said optical downstream signal DS at said downstream wavelength, - to provide said optical upstream signal to said first optical reception unit, - and to provide said reflected signal fraction to said second optical reception unit, and wherein said optical circulator is operable to receive said optical downstream signal from said optical transmission unit and to provide said optical downstream signal to said optical filter, wherein said optical filter is operable - to provide said optical downstream signal to said optical interface, - to receive said reflected signal fraction from said optical interface, - to provide said optical upstream signal to said first optical reception unit, - and to provide said reflected signal fraction to said optical circulator, and wherein said optical circulator is furthermore operable to provide said reflected signal fraction to said second optical reception unit and wherein said optical filter is an optical wavelength divison multiplexing filter, WDM, filter. - an optical transmission unit, - a first and a second optical reception unit (RX1, RX2), - an optical filter, - an optical circulator, and - an optical interface, connectable to an optical transmission link, - to provide said optical downstream signal from said optical transmission unit to said optical interface, - to receive a received optical signal from said optical interface, wherein said received optical signal comprises an optical upstream signal at an upstream wavelength, different from said downstream wavelength, and a reflected signal fraction of said optical downstream signal DS at said downstream wavelength, - to provide said optical upstream signal to said first optical reception unit, - and to provide said reflected signal fraction to said second optical reception unit, and wherein said optical circulator is operable to receive said optical downstream signal from said optical transmission unit and to provide said optical downstream signal to said optical filter, wherein said optical filter is operable - to provide said optical downstream signal to said optical interface, - to receive said reflected signal fraction from said optical interface, - to provide said optical upstream signal to said first optical reception unit, - and to provide said reflected signal fraction to said optical circulator,