Dual-fiber SFP optical modules are good

Dual fiber modules are generally easier to manage and deploy, without the need for wavelength-matched pairs. One of the most common decisions network engineers face is selecting between single fiber SFP and dual fiber SFP modules. BIDI module only has 1 port, wave filtering through the filter of module, and finished the transmitting of 1310nm optical signal. Single fiber modules (BiDi) use one fiber for both transmitting and receiving data. They use a thin fiber. SFP (Small Form-factor Pluggable) is a compact, hot-pluggable network interface module used to connect network devices (switches, routers, firewalls) to fiber optic or copper cables. [pdf]

Passive Optical Networking Company

A passive optical network (PON) is a telecommunications network that uses only unpowered devices to carry signals, as opposed to electronic equipment. In practice, PONs are typically used for the between (ISP) and their customers. In this use, a PON has a topology in which an ISP uses a single device to serve many end-user sites using a system suc. [pdf]