There are different types of PON SFP we have in GPON & EPON.So make sure you have installed the correct SFP in your OLT.
The most important thing in SFP is the transmit power, The SFP which has high transmit power is good. but it depends on the OLT manufacturer too because their OLT must support the high transmit power SFP.
PON fiber optical modules can be divided into GPON fiber optical modules and EPON fiber optical modules.
The GPON fiber optical module is a high-performance and economical fiber optical module used for 2.5Gpbs serial optical data communication applications. The advantage of this fiber optical module is that it can guarantee no damage to the eyes under any failure conditions.
The EPON fiber optical module has SFP, XFP, and SFP+ packaging forms, and its transmission distance can reach 20km, and the receiver part has a sealed preamplifier and a limiting amplifier with LVPECL compatible differential output.
EPON SFP Types.
EPON OLT PX20 or PX20+/PX20++/PX20+++ fiber optical module, suitable for optical network unit and optical line terminal, its transmission distance is 20KM, single-mode with an SC connector interface.
Transmit Power of Epon SFP
The transmit power depends on the types of sfp you are using. high transmit power SFP will adjust more loss in your network.So always you have to choose the PON sfp which has high transmit power.
|PX20||Up to 3dBm|
|PX20+||3 to 5 dBm|
|PX20++||5 to 7 dBm|
GPON SFP Types.
GPON OLT CLASS B+,C+,C++,C+++ fiber optical module, suitable for optical line terminal, its transmission distance is 20KM, rate is 2.5G/1.25G, single mode with a SC connector interface .
B+ SFP module, suitable for optical line terminal, its transmission distance is 20KM, speed is 2.5G/1.25G, single-mode single mode with a SC connector interface.
The main difference is the output optical power. Class C++ and C+++ GPON SFP module output optical power is about 7dBm, the Class C+ GPON SFP module output optical power is about 5dBm. Of course, their optical receiver sensitivity is also different. The Class C++ & C+++ optical receiver sensitivity is best.