GPON vs SFP：What's the difference?

It seems there was a mix-up in the query, so let's provide the correct information. The question refers to GPON and SFP which are different types of network technology.

GPON, or Gigabit Passive Optical Network, is a type of telecommunications technology for supporting internet services across long distances, typically to homes and businesses. It's a point-to-multipoint type network which suggests there's one optical line feeding multiple users. GPON can deliver up to 2.5 Gbps bandwidth on up to 20 km range.

On the other hand, SFP, or Small Form-factor Pluggable, is a compact, hot-pluggable transceiver used for both telecommunication and data communication applications. SFP transceivers are designed to support SONET, Gigabit Ethernet, Fibre Channel, and other communications standards.

In short, GPON is a type of network often used by ISPs (Internet Service Providers) to provide internet services to multiple homes or businesses, while SFP is a type of network transceiver module used to convert electrical signals to optical signals or vice versa, enabling the connectivity in a network.

What's gpon ?

GPON stands for Gigabit Passive Optical Network. It is a type of high-speed network that uses fiber optic cable to deliver broadband to end users. GPON operates in a point-to-multipoint scheme, meaning a single fiber from the provider's central office can serve multiple homes or businesses. It is able to deliver high data speeds and support services like video, data, and voice.

A GPONnetwork consists of OLT (Optical Line Terminals), ONU (Optical Network Unit), and a splitter. The splitter will divide the signal when needed. The OLT takes in all of the optical signals in the form of beams of light from ONUs and will convert it to an electrical signal.
 

Transmission Distance

The transmission distance of conventional gigabit BiDi SFP can be up to 160 km over single-mode fiber cable when using 1590nm/1510nm and 1510nm/1590nm wavelengths. GPON OLT and ONT/ ONU SFP transceivers support a transmission distance up to 20 km with 1490nm/1310nm and 1310nm/1490nm wavelengths.
 

Benefits of Using GPON SFP

Using GPON SFP is considered a more convenient and cost-effective solution for the end customers. And it also reduces the devices that need to be provided by the Internet service provider (ISP). Before the GPON ONT SFP was released and used in GPON networks, the ISP usually needs to install at least an optical modem (a type of ONT with a fiber optic port) and an IP access router, and a Set-Top-Box or video recorder might also be needed if IPTV services are required. The separation of different devices inevitably increased the cost for GPON services.

The newly used GPON SFP is in smaller size and integrates the triple-play services. It has lower consumption as well. The ISP provides a GPON ONT SFP to the customer. This module is usually installed in the hub/router handed to the customer by the ISP. The customer is also able to unplug the fiber optic patch cable and the GPON ONT SFP from the ISP’s hub/router, and then plug them in his own router/switch that is white-listed by the ISP.

GPON SFP OLT transceiver is designed for OLT side in GPON network. GPON SFP uses 1490nm continuous-mode transmitter and 1310nm burst-mode receiver. The transmitter section uses a 1490nm DFB (Distributed Feed Back) LD with automatic power control (APC) function and temperature compensation circuitry to ensure stable extinction ratio overall operating temperature range. And it is Class I laser compliant IEC825 and CDRH standards. The receiver has a hermetically packaged burst-mode APD-TIA (trans-impedance amplifier) pre-amplifier and a burst-mode limiting amplifier with LVPECL compatible differential outputs. The GPON OLT SFP transceiver is a high performance and cost-effective module for serial optical data communication applications to 2.5Gpbs. For GPON transceivers, there are 2 Class available – Class B+ and Class C+. The table below shows the key differences between GPON SFP class B+ and class C+:

Table 2: GPON SFP class B+ vs. GPON SFP class C+

What's SFP?

SFP stands for Small Form-Factor Pluggable. It is a type of transceiver -- a device that can both send and receive data. They are used in communication networks and can plug into a variety of devices such as switches and routers, converting the electrical data signals into optical signals to transmit over a fiber optic cable, and vice versa.
 

What does an SFP port function?

Thanks to an SFP port connection, data can be transferred between two devices using an SFP transceiver and the proper cabling. In other words, the port and the associated SFP transceiver enable long-distance communication between the two devices.

The data transfer rate of the SFP module, which in turn defines what kind of cable is necessary to make the connection, affects the maximum distance that two devices can be linked via an SFP port.
 

What is the purpose of an SFP port?

SFP ports and their matching SFP modules are employed for smooth, high-speed data communications and telecommunications connections over long distances in a range of applications. 

They are frequently used to link one-gigabit network switches together, expanding the capacity and improving the operation of a network. This is useful in industrial, commercial, and military applications where many pieces of equipment need a fast connected connection across a wide area.
 

SFP media support

SFP module types support both single and multimode fiber and Cat5, Cat6, Cat6a and Cat7twisted pair copper. SFP modules designed for use with fiber support a variety of wavelengths and maximum distances up to 2 km with multimode and 40 km with single mode.
 

Connections using Cat6a are limited to approximately 100 m, but cross-talkbetween adjacent cables can limit actual maximum distance. Cat7 cables include additional shielding to reduce cross-talk, but they can be difficult to install due to increased cable thickness.
 

The enhanced SFP (SFP+) specification was released in 2006 with a further update in 2011. SFP+ modules support rates up to 16 Gbps. Like the earlier SFP model, they support both fiber and copper, but copper interconnects are limited to 10 m at 10 Gbps. The SFP+ specification supports single-mode fiber interconnects to 40 km, but some vendors support up to 80 km distances.
 

SFP+ modules are specified for Fibre Channel (FC) at up to 8 Gbps, but some vendors support up to 16 Gbps rates. SFP+ also supports WAN connections based on Optical Transport Network specification OTU2.
 

Some SFP modules, such as GLC-BX-D and GLC-BX-U, support digital optical monitoring, which lets end users monitor the performance of SFPs in real time, tracking metrics, such as temperature, optical output power, optical input power, transceiver supply voltage and laser bias current.