Unveiling the Tech Battle: Class B+ vs. Class C+ in GPON SFP Modules

Posted on Jan 2, 2024 by

Choosing the right GPON SFP (Small Form-Factor Pluggable) modules is crucial when building a robust GPON network. Among them, GPON SFP B+ and GPON SFP C+ modules play pivotal roles in network performance. This article delves into a comprehensive comparison between these two modules, exploring their differences. By understanding their characteristics, we aim to provide guidance for making informed decisions in various network environments, ensuring exceptional performance across all aspects. Join us as we explore the debate between GPON SFP B+ and GPON SFP C+, empowering you to optimize your network performance.

Introduction to GPON SFP Modules

SFP stands for "Small Form-factor Pluggable," and GPON SFP is a gigabit optical transceiver designed specifically for GPON systems, adhering to the ITU-T G.984.2 standard. This bidirectional module, equipped with an SC receptacle, operates over simplex single-mode fiber optic cables. Facilitating communication between the OLT at the Central Office and the ONT at the end user's location, a GPON SFP transmits and receives signals at different wavelengths. Utilizing Optical Wavelength Division Multiplexing (WDM), GPON SFPs efficiently handle both upstream and downstream data. The main advantages of GPON SFP modules include a compact design, easy installation, high-performance data transmission, extensive compatibility, and low power consumption. These features make it an ideal choice for delivering reliable fiber optic access services, providing users and businesses with stable and high-speed network connections.



Figure1: GPON SFP Module Insertion into FS OLT Device

Introduction to SFP B+ and SFP C+ Modules

GPON SFP modules are categorized into GPON OLT SFP and GPON ONT/ONU SFP depending on the devices they are used in GPON network. Additionally, there are Class B+ GPON SFP and Class C+ GPON SFP in GPON module. Class B+ modules and Class C+ modules are defined by the ITU-T (International Telecommunication Union Telecommunication Standardization Sector) GPON standard. These standards outline the transmission equipment and protocols used in Fiber to the Home (FTTH) networks.

In the GPON standard, Class B+ and Class C+ modules have specific performance requirements and technical specifications. Class B+ modules are typically suitable for common network deployments, providing a cost-effective and balanced performance. On the other hand, Class C+ modules usually have higher performance capabilities and are suitable for scenarios with higher requirements for network capacity and complexity.

In summary, these classifications aim to provide flexibility for network operators, allowing them to choose the appropriate optical modules based on different application scenarios to meet varying network requirements.


naming of class B+ and class C+ module

Figure2: The naming Rules for Class B+ and Class C+ Modules of FS

Differences Between SFP B+ and SFP C+ Modules

The major differences between SFP B+ and SFP C+ modules are the transmit power and receiver sensitivity. The table below lists the importanct parameter of Class B+ GPON SFP and Class C+ GPON SFP to help you understand their differences correctly. Meanwhile, the capacity of supported ONTs distinguishes between different classes of OLT GPON SFP modules. Certain providers indicate that GPON SFP class B+ supports 32 ONTs/ONUs, whereas OLT GPON SFP class C+ can accommodate up to 64 ONTs/ONUs.

Transceiver Type
Tx: 1490nm
Rx: 1310nm
Tx: 1490nm
Rx: 1310nm
Tx: 2.488Gbit/s
Rx: 1.244Gbit/s
Tx: 2.488Gbit/s
Rx: 1.244Gbit/s
Min Output Power
Max Output Power
Optical Receiver Sensitivity
Extinction Ratio
Optical Connector
Fiber Type
Single Mode
Single Mode

GPON Solution


Figure3: GPON Solution with Class B+/C+ Module


The ultimate decision for network operators lies in carefully weighing various factors, including transmit power and receiver sensitivity, to choose the module that best suits their network architecture and performance requirements. Ensuring that the selected module seamlessly integrates into the existing network infrastructure while providing stable and efficient data transmission is crucial for ensuring smooth network operation. Before making a decision, a detailed understanding and comparison of the network performance of SFP B+ and SFP C+ are essential steps to guarantee optimal performance of network equipment and services.

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