Arhitecture of Optical Access Network

Hello, everyone!

From the architecture diagram, the optical access network comprises the following scenarios:
àFTTB
     -SBU: Single business unit; providing a comparatively small number of ports such as POTS, 10/100/100BASE-T and DS1/T1/E1 ports
     -MTU: Business Multi-tentant unit;providing a comparatively larger number of ports,including POTS, 10/100/100BASE-T and DS1/T1/E1 ports.

àFTTC and FTTCab scenario
     -MDU:Multi-dwelling unit;providing a comparatively larger number of ports,including 10/100/100BASE-T,VDSL2,   and so on.

àFTTH scenario
     -SFU:Single family unit, providing a comparatively small number of ports, including following types: POTS, 10/100/100BASE-T, and RF.

Thanks.