What Is SFP
In the ever-evolving network technology, the need for efficient and adaptable components has become more crucial than ever. One such essential component that has emerged as a cornerstone in this technological revolution is the small form-factor pluggable (SFP) module. This passage explores those problems: SFP module overview and functionality and applications and how to choose suitable SFP modules.
SFP Module Overview and Functionality
As network infrastructure demands keep on growing, the small form-factor pluggable (SFP) module has solidified its position as a crucial part of network communications technology. The SFP module has been used as a universal industry standard by manufacturers and service providers worldwide for more than 20 years. It is a persistent industry linchpin. The SFP has demonstrated remarkable versatility in a variety of network contexts, including SONET, Gigabit Ethernet, Fibre Channel, Passive Optical Networks (PON), and other communication standards. The unique design of the SFP module ensures stable operation in extreme environmental conditions such as high temperature, humidity and electromagnetic interference. This passage is designed to impart foundational insights into SFP modules for those embarking on the path of network technology.
How to Choose an Ethernet SFP Module?
Choose SFP Copper or Fiber Module?
The SFP module is available in various types based on different classification criteria. It can be used with both copper Ethernet cables and fiber optic cables.
On the fiber optics side, there are single mode SFP module and multimode SFP module, which allows users to select the appropriate transceiver according to the required optical range for the network. Operation wavelength ranges from 850nm to 1550nm. Commonly, 850nm SFP can reach up to 550 meters with multimode fiber optics, and the 1550nm SFP supports up to a maximum of 160km via single mode fiber cables. On the other hand, copper SFP modules primarily are 1000BASE-T SFP and 1000BASE-TX SFP modules, which are excellent used in gigabit Ethernet networking within 100 meters.
Choose SFP or Advanced SFP+?
SFP and SFP+ are applied at different transmission speeds. The SFP module supports 1Gb data rate, and the SFP type includes 1000base-T/TX, 1000base-SX, 1000base-LX/LX10, 1000base-BX10, 1000base-LX/LH, 1000base-EX, 1000base-ZX and so on.
SFP+ is used in 10-gigabit Ethernet applications but shares the same form factor with SFP. In the SFP+ family, there are primarily SFP+ SR, SFP+ LR, and SFP+ ZR modules for 10 Gigabit ethernet networking.
Choose an MSA Compatible SFP or Not?
Compatibility is often the most important parameter users care about when buying an MSA SFP module. MSA (multi-source agreement) is an agreement supported by a number of manufacturers who came together to collaborate and standardize the fit-form and try to provide a reliable means of mixing and matching SFP brands successfully. Third-party companies also have developed their own tools to program SFP modules to be compatible with the OEM. So, the MSA compatibility Gigabit SFP module can be used successfully in most networks.
How Many Types of SFP Transceivers
How Many Types of SFP Transceivers Do You Know?
There are many 1G SFP types available today like copper RJ45 SFP, fiber optic SFP, and WDM SFP modules, so what makes them different, and how do you know which is best for you? According to different classification standards, 1G modules have different types.
By SFP Media Type
1G Ethernet SFP module can work over optical fiber and Ethernet cables, so fiber SFP module and copper SFP are the two main SFP types.
Within the fiber SFP category, there are two distinct types—single-mode SFPs, which are compatible with single-mode fibers, and multimode SFPs, which are suited for multimode fibers. These classifications correspond with the specific fiber patch cables they interface with. Refer to Table 1 for a detailed comparison of the key differences between single-mode and
Specfication | Multimode SFP | Single-mode SFP |
Fiber Type | 62.5/125µm or 50/125µm core MMF | 9/125µm core SMF |
Working Wavelength | Mainly in 850 nm and 1300 nm | Mainly in 1310 nm and 1550 nm |
Color Coding | Black | Blue for 1310nm SFP Yellow for 1550nm SFP |
Transmission Distance | 100m / 550m | 2km up to 200km |
The 1000Base-T RJ45 SFP transceiver module represents a robust interface for copper-based networking, leveraging the ubiquitous twisted-pair cabling standards inclusive of Category 5e (Cat5e), Category 6 (Cat6), and the advanced Category 6a (Cat6a). This module is specially engineered to deliver high-speed gigabit connectivity across these copper mediums with an operational reach of up to 100 meters, ensuring compatibility and optimal performance in both data center architectures and enterprise LAN environments. Its design adheres to industry standards, offering a high degree of reliability and interoperability for network expansions or integrations where existing copper network infrastructure is leveraged.
Specfication | Multimode SFP | Single-mode SFP |
Fiber Type | 62.5/125µm or 50/125µm core MMF | 9/125µm core SMF |
Working Wavelength | Mainly in 850 nm and 1300 nm | Mainly in 1310 nm and 1550 nm |
Color Coding | Black | Blue for 1310nm SFP Yellow for 1550nm SFP |
Transmission Distance | 100m / 550m | 2km up to 200km |
The 1000Base-T RJ45 SFP transceiver module represents a robust interface for copper-based networking, leveraging the ubiquitous twisted-pair cabling standards inclusive of Category 5e (Cat5e), Category 6 (Cat6), and the advanced Category 6a (Cat6a). This module is specially engineered to deliver high-speed gigabit connectivity across these copper mediums with an operational reach of up to 100 meters, ensuring compatibility and optimal performance in both data center architectures and enterprise LAN environments. Its design adheres to industry standards, offering a high degree of reliability and interoperability for network expansions or integrations where existing copper network infrastructure is leveraged.
By SFP Cable Core Diameter
FS has different types of 1G fiber SFP transceivers, including multi-mode, single-mode, BiDi, and WDM. For specific transmission range function details, please refer to Table 2.
Product | Wavelength | Max. Transmit Distance | Connector | |
Multimode SFP | 1000BASE-SX-85 | 850nm | 550m | LC Duplex |
1000BASE-SX-31 | 1310nm | 2km | LC Duplex | |
Single mode SFP | 1000BASE-LX-31 | 1310nm | 20km | LC Duplex |
1000BASE-LH-31 | 1310nm | 40km | LC Duplex | |
1000BASE-EX-55 | 1550nm | 40km | LC Duplex | |
1000BASE-ZX-55 | 1550nm | 80km | LC Duplex | |
1000BASE-EZX-55 | 1550nm | 120km | LC Duplex | |
1000BASE-ZXC-55 | 1550nm | 160km | LC Duplex | |
BiDi SFP | 1000BASE-BX | 1310nm/1550nm, 1310nm/1490nm, 1510nm/1590nm | 2km~160km | LC Duplex/Simplex |
WDM SFP | 1000BASE-CWDM | 1270nm~1610nm | 20km~160km | LC Duplex |
1000BASE-DWDM | C17~C61 | 80km~100km | LC Duplex |
By SFP Operating Temperature
According to the different operating temperatures, SFP modules can usually be divided into three types:
At present, our company only provides commercial-grade and industrial-grade modules. It is very important to choose the SFP module with the appropriate operating temperature range according to actual needs and environmental conditions to ensure the stability and reliability of network equipment.
By SFP Variants
SFP transceivers come in various variants to cater to different networking requirements, including data rate, distance, wavelength, and compatibility with different types of optical fiber. Here is a brief overview of some common SFP variant types:
A variant that is designed for 25 Gbps Ethernet connections. This allows for higher speeds and is backwards compatible with SFP+ ports.
The selection of an appropriate SFP variant depends on factors including required throughput, distance the signal needs to travel, type of fiber optic cabling, and environmental conditions. It is important to match the SFP specification to the networking equipment, as well as to the operational requirements, to ensure compatibility and optimal performance. For in-depth insights into the distinctions between these advanced transceiver modules, I invite you to explore
By SFP Application
Based on different applications, SFP types are usually categorized by the following types.
Regular SFP: Most commonly transceivers that deliver data via a duplex fiber. Based on market development and user requests, 2.5G SFP and 100M SFP have emerged successively
BIDI SFP: Can transmit and receive signals in simplex fiber.
WDM SFPs: Support CWDM/DWDM transmission to maximize the bandwidth while saving the fiber cabling.
SONET/SDH SFP: Compatible with the SONET/SDH and ATM standard which covers the standard range of data rates extending from OC-3/STM-1 (155 Mbps) to OC-48/STM-16 (2488 Gbps) for multimode (MM), short-reach (SR), intermediate-reach (IR1), and long-reach (LR1/LR2) applications.
PON SFPs: Used in the Optical Line Terminal (OLT) at the Central Office and the Optical Network Terminal/Unit (ONT/ONU) at the subscriber’s premises.
3G-SDI video SFPs: Designed to meet the high standard video transmission needs in the High Definition (HD) environment.
SONET/SDH SFP: Compatible with the SONET/SDH and ATM standard which covers the standard range of data rates extending from OC-3/STM-1 (155 Mbps) to OC-48/STM-16 (2488 Gbps) for multimode (MM), short-reach (SR), intermediate-reach (IR1), and long-reach (LR1/LR2) applications.
Fibre Channel SFP: A high-speed network technology (commonly running at 1, 2, 4, 8, 16, 32, and 128 gigabits per second rates) primarily used to connect computer data storage to servers in the SAN data center environment.
Each category serves a unique role in network architecture, with different performance metrics and standardized compliance to ensure connectivity and communication across a variety of platforms.
What is an SFP module?
Also known as a mini gigabit interface converter, a small form-factor pluggable module is a hot-swappable device with both a transmitting and receiving side. It can be plugged directly into the physical port of a networking device. It can realize electrical and optical signal conversion to extend the original link distance. Because it accepts both optical and copper cables, it is widely supported by several different networking devices.
What SFP modules are used for?
An SFP module is used to interconnect fiber cables to network switches and other communication devices, such as industrial Ethernet switches and media converters. The hot-swappable device allows the user to equip an interface port with any suitable type of transceiver, which is often necessary for fiber optic connections.
SFP modules support several different communication standards, such as gigabit ethernet, synchronous digital hierarchy, synchronous optical networking, and fiber channel. In most cases, SFP devices are used in 1G network transmission over both short and long distances, depending on the classification standard.
Types of SFP modules
There are many different types of SFP modules that work with different wavelengths at various distances. Some of the main types of SFP modules include:
– 1000BASE-T SFP: designed with an RJ45 interface and supports a network distance of up to 100 meters when operating on a CAT5 cable.
– 1000BASE-SX SFP: a multimode short-range SFP that works on 850-nanometer wavelength over multimode LC fiber and can reach distances of up to 550 meters.
– 1000BASE-LX SFP: used for long-distance transmission and supports a 10-kilometer link operating on a 1310-nanometer wavelength over a single-mode duplex LC cable.
– 1000BASE-EX SFP: can achieve distances of 40 kilometers over single-mode duplex LC cables.
– 1000BASE-ZX SFP: supports an 80-kilometer link over single-mode duplex LC cables.
SFP, SFP+, SFP28, QSFP+, QSFP28, What Are the Differences?
SFP, SFP+, SFP28, QSFP+, and QSFP28 are different fiber transceiver types on the market. They are all hot-pluggable optical modules that are used to connect network switches or other devices. Then, SFP vs. SFP+, SFP28 vs. SFP+, QSFP vs. QSFP28, what are their differences? Can SFP28 transceiver plug into SFP+ slots? And how to choose between these five form factors transceiver modules? All explanations are here.
What are They?
Before concluding the differences of SFP vs SFP+ vs SFP28 vs QSFP+ vs QSFP28, it’s wise to figure out what those form factors stand for.
SFP: SFP was first introduced in 2001, and built to replace the larger form factor GBIC and support data rates of up to 1G data rate. But with the demands for higher bandwidths like 5G applications or IoT, 1G SFP modules nowadays are estimated to be out of the market in the future, although they still have some market share.
SFP+: 2006 saw the introduction of SFP+, an enhanced version of SFP with a higher data rate of up to 10 Gbps. SFP+ module is now still a dominant industry format transceiver module. Data transmission is available at 8Gbps, 10Gbps, and 16Gbps. Transmission distances cover from 30m to 120km and SFP+ transceivers are available with several different connector types such as LC Duplex, LC Simplex, and RJ45.
SFP28: With the same physical dimensions as the SFP and SFP+, the SFP28 fiber transceiver type was launched in 2014 and designed for up to 25Gbps transmission rate. Mainly used for 25G Ethernet and 100G (4x25Gbps) Ethernet.
QSFP+: Launched in 2012, QSFP+ (Enhanced Quad Small Form-factor Pluggable) is composed of 4 channels of 10Gb/s rate that support LC duplex and MPO-12 fiber connectors.
QSFP28: QSFP28 was also introduced in 2014 and shares the same physical dimensions as QSFP+, but uses 4 lanes of 25Gbps. QSFP28 is now the standard interface of choice for 100G applications.
More specifications of SFP vs SFP+ vs SFP28 vs QSFP+ vs QSFP28 are listed in the following Table 1.
Optics Type | Standard | Data Rate | Wavelength | Fiber Type | Max Distance | Typical Connector | DOM | Operating Temperature |
SFP | SFP MSA | 155Mbps 622Mbps 1.25Gbps 2.125Gbps 2.5Gbps 3Gbps 4.25Gbps | 850nm 1310nm 1550nm CWDM DWDM BIDI | OM1 OM2 OS1 OS2 | 160km | LC SC RJ-45 | NO or YES | Commercial Industrial |
SFP+ | IEE802.3ae SFF-8431 SFF-8432 | 6Gbps 8.5Gbps 10Gbps | 850nm 1310nm 1550nm CWDM DWDM BIDI Tunable Copper | OM3 OM4 OS1 OS2 | 120km | LC RJ-45 | YES | Commercial Industrial |
QSFP+ | IEEE 802.3ba QSFP+ MSA SFF-8436 SFF-8636 Infiniband 40G QDR | 41.2Gbps | 850nm 1310nm 832-918nm | OM3 OM4 OS1 OS2 | 40km | LC MTP/MPO | YES | Commercial Industrial |
SFP28 | IEEE 802.3by SFP28 MSA SFF-8472 SFF-8432 | 25.78Gbps | 850nm 1310nm | OM3 OM4 OS1 OS2 | 10km | LC | YES | Commercial Industrial |
QSFP28 | IEEE 802.3bm QSFP28 MSA SFF-8665 SFF-8636 | 103Gbps 112Gbps | 850nm 1310nm CWDM4 | OM3 OM4 OS1 OS2 | 80km | LC MTP/MPO-12 | YES | Commercial Industrial |
By SFP Cable Core Diameter
FS has different types of 1G fiber SFP transceivers, including multi-mode, single-mode, BiDi, and WDM. For specific transmission range function details, please refer to Table 2.
Product | Wavelength | Max. Transmit Distance | Connector | |
Multimode SFP | 1000BASE-SX-85 | 850nm | 550m | LC Duplex |
1000BASE-SX-31 | 1310nm | 2km | LC Duplex | |
Single mode SFP | 1000BASE-LX-31 | 1310nm | 20km | LC Duplex |
1000BASE-LH-31 | 1310nm | 40km | LC Duplex | |
1000BASE-EX-55 | 1550nm | 40km | LC Duplex | |
1000BASE-ZX-55 | 1550nm | 80km | LC Duplex | |
1000BASE-EZX-55 | 1550nm | 120km | LC Duplex | |
1000BASE-ZXC-55 | 1550nm | 160km | LC Duplex | |
BiDi SFP | 1000BASE-BX | 1310nm/1550nm, 1310nm/1490nm, 1510nm/1590nm | 2km~160km | LC Duplex/Simplex |
WDM SFP | 1000BASE-CWDM | 1270nm~1610nm | 20km~160km | LC Duplex |
1000BASE-DWDM | C17~C61 | 80km~100km | LC Duplex |
Comparison of SFP vs SFP+ vs SFP28 vs QSFP+ vs QSFP28
SFP vs SFP+
Same size with different speeds and compatibility. SFP+ is used in 10-Gigabit Ethernet applications while SFP is for 100BASE or 1000BASE applications. SFP complies with the standards of IEEE802.3 and SFF-8472 while SFP+ is based on SFF-8431. SFP+ ports can accept SFP optics but at a reduced speed of 1 Gbit/s. An SFP+ transceiver can not be plugged into an SFP port, otherwise, the product or port may be damaged. Normally, SFP+ is more expensive than SFP.
SFP+ vs SFP28
SFP+ is mainly linked to 10G, while SFP28 is commonly associated with 25G connections. They use the same form factor, and the pinouts of SFP28 and SFP+ connectors are mating compatible. So SFP28 will work with SFP+ optics but at a reduced speed of 10 Gbit/s. 10G SFP+ modules will work well with the SFP28 port on a network switch if the port can be set up for 10G transmission, otherwise, the SFP+ modules can not work.
SFP+ vs QSFP+
The primary difference between QSFP+ and SFP is the quad form. QSFP+ is an evolution of QSFP to support four 10 Gbit/s channels carrying 10-Gigabit Ethernet, 10G Fiber Channel, or InfiniBand, which allows for 4x 10G cables and stackable networking designs that achieve better throughput. QSFP+ can replace 4 standard SFP+ transceivers, resulting in greater port density and overall system cost savings over SFP+. Get details about QSFP here: What Is QSFP+ Module: QSFP+ Transceiver Wiki and Types.
SFP28 vs QSFP28
SFP28 and QSFP28 transceivers actually adopt different sizes and working principles. SFP28 supports only one channel with 25 Gbit/s, while QSFP28 supports 4 separate lanes, and each is 25 Gbit/s. Both of them can be used in 100G networks, but the SFP28 is applied in the form of QSFP28 to the SFP28 breakout solution. Read article Introduction to 100G QSFP28 Optical Transceiver to gain more pieces of information.
Conclusion
It’s clear that the main driving force behind the evolution of optical transceivers is the need to achieve higher bandwidth rates with smaller form factors. In modern, dense networks, small form factors are a constant necessity. SFP vs SFP+ vs SFP28 vs QSFP+ vs QSFP28, after a clear understanding of them, you also have to consider your network traffic, transmission distance, and future-proof networking requirements to ensure the right selection.
How to Tell if My SFP is Single-Mode or Multimode
To determine if your SFP (Small Form-factor Pluggable) module is single mode or multimode, you can look for specific markings or labels on the module itself. Typically, single mode SFP modules are labeled as “SM” or “single mode,” while multimode modules may be labeled as “MM” or “multimode.” Additionally, single mode modules often have yellow-colored connectors, while multimode modules may have orange or aqua-colored connectors. It is important to check the specifications or documentation provided by the manufacturer to confirm the mode of your SFP module, as the labeling and color coding conventions may vary.
What is Single-Mode vs. Multimode SFP?
SFP, or Small Form-factor Pluggable, is a type of transceiver used in data communication and telecommunications networks. It allows for the connection of a network device to various types of fiber optic or copper cabling. SFP modules are standardized by the MSA (Multi-Source Agreement), meaning they can be used across different brands of networking equipment. There are two primary types of fiber optic SFP transceivers based on the mode of the fiber: Single-Mode SFP (SMF) and Multimode SFP (MMF).
Single-Mode SFP
Fiber Type: Single-mode fiber (SMF) uses one mode of light to propagate through the fiber. This means there is a single light path and it’s usually a laser-based light source.
Core Diameter: A single-mode fiber has a small core diameter, typically around 9 micrometers.
Distance: Single-mode SFP can transmit data over long distances, generally up to 150 kilometers, depending on the SFP model and its optical budget.
Speed and Bandwidth: Single-mode fiber offers higher bandwidth than multimode and can support higher data rates because it has no modal dispersion due to the single light path.
Color Coding: Single-mode SFPs are typically identified by blue-colored bail or coding.
Multimode SFP
Fiber Type: Multimode fiber (MMF) allows multiple modes or light paths to propagate through the fiber, resulting in differential mode delay. This is usually an LED-based light source but can be laser-optimized for higher performance on later multimode fiber versions.
Core Diameter: Multimode fiber has a larger core size, usually 50 or 62.5 micrometers, which enables multiple light paths.
Distance: Multimode SFPs are suitable for shorter distances, generally up to 2 kilometers, but most are used for distances under 600 meters.
Speed and Bandwidth: Multimode SFPs offer high bandwidth at short distances, but the bandwidth potential decreases with increased cable length due to modal dispersion.
Color Coding: Multimode SFPs often have a black or beige bail, or aqua in the case of the enhanced 10Gbps versions (OM3/OM4).
When choosing an SFP for a network application, it’s essential to consider the required distance, data rate, compatibility with the existing network infrastructure, and the cost. Single-mode fiber solutions are generally more suitable for long-haul applications, whereas multimode fiber is often preferred for short-range data communications, such as within a data center or a building.
Check the Labeling or Product Specifications of the SFP Module.
To ascertain the mode of your Small Form-factor Pluggable (SFP) module, begin by examining its label or documented specifications. Manufacturers typically specify on these labels or within the documentation whether the SFP module is designed for single mode (“SM”) or
multimode (“MM”) fibers. Look for these indicators in the text to identify the mode.
When the label or specifications do not provide clear insights, consider inspecting the SFP module visually. The physical attributes between single mode and multimode SFP modules differ notably. Single mode modules often allow for greater transmission distances with a fiber core diameter around 9 microns, while multimode modules accommodate less distance and have a broader core diameter, generally 50 or 62.5 microns.
Bear in mind the existence of advanced SFP modules that are equipped to handle both single mode and multimode fibers; these are termed “dual-mode” or “universal” SFPs. This type will automatically adapt to the connected fiber type. When using a dual-mode SFP module, the mode may not be visibly evident, thus necessitating a check of the product’s specifics or a consultation with the manufacturer.
To sum up, verifying whether your SFP module is single mode or multimode involves initial scrutiny of labels or specifications, followed by physical examination, and when in doubt, reaching out to the manufacturer for definitive answers.
Outer Appearance Identification – Single-Mode vs. Multimode SFP Color Coding
Single-mode SFP vs multimode SFP is color-coded with different Bale Clasp. Though the color-coding rule is not total conformity for different vendors, generally the Bale Clasp of multimode SFP is black, and fiber patch cables used with multimode SFP are usually orange (OM1/OM2), aqua green (OM3/OM4), green (OM5).
The most common color of single-mode SFP Bale Clasp is blue, there are also some in yellow, red, etc. Fiber optic jumpers used with single-mode optical modules are generally yellow.
SFP Slide Guide
SFP Short Explain
1. What is an SFP?
SFP stands for Small Form-factor Pluggable.
It is a small, removable module that you plug into network devices like:
- Switches
- Routers
- Media converters
An SFP lets the device send and receive data over:
- Fiber optic cable (most common)
- Sometimes copper cable (RJ45 SFPs)
Instead of having fixed ports, SFPs make the port flexible.
2. What is a Fiber SFP?
A Fiber SFP is an SFP module that uses fiber-optic cables to transmit data as light signals.
- Electrical signals (from the switch) ➜ Light (into fiber)
- Light (from fiber) ➜ Electrical signals (into the switch)
3. Why Fiber SFPs are used
Fiber SFPs are used when you need:
- Long distance communication (hundreds of meters to kilometers)
- High speed (1G, 10G, 25G, 40G, 100G)
- No interference (fiber is immune to electrical noise)
- Reliable backbone connections
4. Main parts of a Fiber SFP
- Laser transmitter – sends light
- Photodiode receiver – receives light
- Optical connector – connects the fiber cable
- EEPROM – stores module information
Metal housing – reduces interference and heat
- 5. Types of Fiber SFPs (Very Important)
- A. By Speed
SFP Type Speed SFP 1 Gbps SFP+ 10 Gbps SFP28 25 Gbps QSFP+ 40 Gbps QSFP28 100 Gbps
B. By Fiber Type
1. Multimode Fiber SFP (Short Distance)
Uses MMF fiber
- Color: usually aqua
- Distance: 100m – 550m
- Laser: 850nm
- Type name: SX
Example:
- 1000BASE-SX
- 10GBASE-SR
2. Single-Mode Fiber SFP (Long Distance)
Uses SMF fiber
- Color: usually yellow
- Distance: 10km – 80km+
- Laser: 1310nm or 1550nm
- Type name: LX, LR, ER, ZR
Example:
- 1000BASE-LX
- 10GBASE-LR
C. By Connector Type
Most common:
- LC connector (small, modern)
- SC connector (older, bigger)
6. Common Fiber SFP Names Explained
Let’s break one down:
Example: 1000BASE-LX SFP
- 1000 = 1 Gbps
- BASE = baseband signaling
- LX = Long wavelength (1310nm)
- Works on single-mode fiber
- Distance ≈ 10 km
7. Duplex vs Simplex (BiDi)
Duplex Fiber SFP
- Uses 2 fibers
- One fiber transmit (TX)
- One fiber receive (RX)
BiDi (Bidirectional) SFP
- Uses 1 fiber
- TX and RX use different wavelengths
- Must be used in pairs
Example:
- SFP-A: TX 1310 / RX 1550
- SFP-B: TX 1550 / RX 1310
8. How Fiber SFPs are installed
- Insert SFP into switch/router
- Lock it in place
- Connect fiber cable
Ensure:
- Correct fiber type
- Correct wavelength
- Same speed on both ends
9. Compatibility Rules (Very Important)
- Speed must match on both sides
- Fiber type must match (SMF vs MMF)
- Wavelength must match
- Some vendors lock SFPs (Cisco, HP, etc.)
⚠️ A 10G SFP+ will not work in a 1G SFP port.
10. Advantages of Fiber SFP
✅ Long distance
✅ High speed
✅ Low signal loss
✅ No electrical interference
✅ Hot-swappable
SFP, SFP+, QSFP, SFP28,QSFPDD
1. What these terms mean (big picture)
All of these are pluggable optical transceivers.
They convert electrical signals ↔ light signals so network devices can communicate over fiber.
They differ by:
- Speed
- Form factor (size)
- Number of lanes
- Distance
- Use case (Ethernet vs PON)
2. Standard Ethernet Optical Modules (Data Networks)
A. SFP Family (Single-lane era)
🔹 SFP (1G)
- Speed: 1 Gbps
- Lanes: 1 × 1G
- Fiber: SMF / MMF
- Common types: SX, LX, EX, ZX
- Distance: 100 m → 80 km
- Use: Access switches, legacy networks
🔹 SFP+ (10G)
- Speed: 10 Gbps
- Lanes: 1 × 10G
- Common types: SR, LR, ER
- Distance: 300 m → 40 km
- Use: Servers, uplinks, data centers
🔹 SFP28 (25G)
- Speed: 25 Gbps
- Lanes: 1 × 25G
- Same size as SFP+
- Use: Modern access & leaf switches
🔹 SFP56 (50G)
- Speed: 50 Gbps
- Lanes: 1 × 50G
- Advanced modulation (PAM4)
- Use: 5G fronthaul, next-gen access
B. QSFP Family (Multi-lane era)
🔹 QSFP+ (40G)
- Speed: 40 Gbps
- Lanes: 4 × 10G
- Fiber: SR4, LR4
- Use: Older data-center backbones
🔹 QSFP28 (100G)
- Speed: 100 Gbps
- Lanes: 4 × 25G
- Very common
- Use: Core, spine-leaf, data centers
🔹 QSFP56 (200G)
- Speed: 200 Gbps
- Lanes: 4 × 50G
- Uses PAM4
- Use: High-capacity spine links
C. New Generation (400G / 800G)
🔹 QSFP-DD (400G)
- Speed: 400 Gbps
- Lanes: 8 × 50G (or 8 × 100G PAM4)
- DD = Double Density
- Use: Hyperscale data centers
Common optics:
- 400G-SR8
- 400G-DR4
- 400G-FR4 / LR4
🔹 OSFP (400G & 800G)
- Speed: 400G and 800G
- Lanes: up to 8 × 100G
- Bigger than QSFP
- Better cooling
- Use: AI clusters, HPC
🔹 QSFP-DD800 (800G)
- Speed: 800 Gbps
- Lanes: 8 × 100G PAM4
- Use: AI fabrics, ultra-scale DCs
3. Speed Summary Table
| Module | Speed |
|---|---|
| SFP | 1G |
| SFP+ | 10G |
| SFP28 | 25G |
| SFP56 | 50G |
| QSFP+ | 40G |
| QSFP28 | 100G |
| QSFP56 | 200G |
| QSFP-DD | 400G |
| OSFP | 400G / 800G |
| QSFP-DD800 | 800G |
4. PON SFP Modules (Access Networks – ISPs)
⚠️ PON is NOT Ethernet
Used between OLT ↔ ONT, not switches.
A. GPON Family
🔹 GPON SFP
- Downstream: 2.5G
- Upstream: 1.25G
- Distance: up to 20 km
- Split: 1:64 / 1:128
🔹 XG-PON
- Down: 10G
- Up: 2.5G
🔹 XGS-PON (Very common)
- Down: 10G
- Up: 10G
- Use: Modern FTTH
🔹 25G-PON
- Down: 25G
- Up: 25G
- Use: High-density fiber access
🔹 50G-PON (Next-Gen)
- Down: 50G
- Up: 50G
- Use: Future FTTH & 5G transport
PON vs Ethernet (Quick Compare)
| Feature | Ethernet SFP | PON SFP |
|---|---|---|
| Protocol | Ethernet | PON |
| Connection | Point-to-point | Point-to-multipoint |
| Devices | Switch ↔ Switch | OLT ↔ ONT |
| Interoperable | Yes | Vendor-locked |
5. Fiber & Distance Types
MMF (Short range)
- SR, SX
- 100 m – 500 m
- 850 nm
SMF (Long range)
- LR, ER, ZR, DR, FR
- 2 km – 80 km+
- 1310 / 1550 nm
6. Important Compatibility Rules
✅ Speed must match
✅ Form factor must match port
✅ Fiber type must match
✅ Wavelength must match
⚠️ PON optics only work with correct OLT
⚠️ High-speed optics need proper cooling
7. Real-World Use Cases
- SFP/SFP+ → Access & servers
- SFP28/SFP56 → Modern access, 5G
- QSFP28 → Data-center backbone
- 400G/800G → AI, cloud, hyperscale
- PON SFP → ISP fiber-to-home
1. SR Short Range SFP
Distance: ,100 m (OM3),300 m (OM4),400 m (OM5),Fiber: Multimode fiber (MMF),Wavelength: 850 nm,Speeds:
- 1G (SX)
- 10G (SR)
- 25G (SR)
- 40G (SR4)
- 100G (SR4)
- 400G (SR8)
Use case:
- Inside racks
- Same room / same data hall
✅ Cheapest optics
❌ Short distance
❌ MMF only
2. LR Long Range SFP
- Distance: ~10 km
- Fiber: Single-mode fiber
- Wavelength: 1310 nm
Speeds:
- 1G-LX
- 10G-LR
- 25G-LR
- 100G-LR4
Use case:
- Campus networks
- Building-to-building
- Metro edge
✅ Most common SMF optic
⚠️ Higher cost than DR/FR
3. ER Extended Reach
- Distance: ~40 km
- Fiber: Single-mode fiber
- Wavelength: 1550 nm
Speeds:
- 10G-ER
- 25G-ER
- 100G-ER4
Use case:
- Metro networks
- ISP aggregation
⚠️ High power laser
⚠️ Often needs link budget planning
ZR Very Long Reach
- Distance: ~80 km (or more)
- Fiber: Single-mode fiber
- Wavelength: 1550 nm
Speeds:
- 10G-ZR
- 100G-ZR
- 400G-ZR / ZR+
Use case:
- City-to-city links
- ISP backbone
- DCI over DWDM
⚠️ Expensive
⚠️ Often DWDM-capable
⚠️ Attenuators may be required
Common Wavelengths (nm) for SFP Modules
850 nm (near-infrared)
- Common Use: Multi-mode fiber
- Typical Modules: SFP, SFP+ SR (Short Range)
- Data Rates: Often 1 Gbps to 10 Gbps
- Range: Typically up to 300 meters for SFP+ SR on multi-mode fiber
- Description: This wavelength is used for short-range communications over multi-mode fiber (MMF), often in data center or enterprise networks.2
1310 nm (infrared)
- Common Use: Single-mode fiber and sometimes multi-mode fiber
- Typical Modules: SFP+ LR (Long Range), SFP+ ER (Extended Range)
- Data Rates: 1 Gbps to 10 Gbps and higher
- Range: Can range from 10 km to 40 km or more (depending on module and fiber quality)
- Description: A commonly used wavelength for longer-range transmissions over single-mode fiber (SMF). It is often used for longer-distance Ethernet links, such as in WAN or fiber backbone applications.
1550 nm (infrared)
- Common Use: Single-mode fiber
- Typical Modules: SFP+ ZR (Extended Range), SFP-ER (Extended Reach)
- Data Rates: 1 Gbps, 10 Gbps, and above
- Range: Up to 80 km or more with single-mode fiber
- Description: This wavelength is often used for very long-distance transmission and is typically deployed in telecom and fiber-optic backbone applications. It’s commonly used in Dense Wavelength Division Multiplexing (DWDM).
1264.5 nm to 1337.5 nm (CWDM – Coarse Wavelength Division Multiplexing)
- Common Use: Single-mode fiber
- Typical Modules: CWDM SFP (Coarse Wavelength Division Multiplexing)
- Data Rates: Usually 1 Gbps to 10 Gbps
- Range: Varies, typically up to 80 km depending on the specific CWDM channel.
- Description: CWDM modules utilize multiple wavelengths (channels) within the 1264.5 nm to 1337.5 nm range to send multiple data streams over the same fiber, significantly increasing the fiber’s capacity.
DWDM (Dense Wavelength Division Multiplexing)
- Common Use: Single-mode fiber
- Typical Modules: DWDM SFP and SFP+ DWDM
- Data Rates: 1 Gbps, 10 Gbps, and sometimes 100 Gbps
- Range: Can span over hundreds of kilometers depending on the fiber and module used.
- Description: DWDM uses a dense set of wavelengths (typically from 1525 nm to 1565 nm) for very high-capacity long-distance transmission. DWDM technology is mainly used in large-scale telecom networks and fiber optic backbones.
| Wavelength (nm) | Common Use | Fiber Type | Typical Module Types | Range/Distance |
|---|---|---|---|---|
| 850 nm | Short-range, data center | Multi-mode fiber | SFP, SFP+ SR | Up to 300 meters |
| 1310 nm | Long-range, telecom, data centers | Single-mode fiber | SFP+ LR, SFP+ ER | 10 km to 40 km (single-mode) |
| 1550 nm | Very long-range, telecom backbone | Single-mode fiber | SFP+ ZR, SFP-ER | 40 km to 80+ km |
| 1264.5 to 1337.5 nm (CWDM) | Multiple wavelengths over a single fiber | Single-mode fiber | CWDM SFP | 40 km to 80+ km |
| 1525 to 1565 nm (DWDM) | High-capacity, long-range telecom | Single-mode fiber | DWDM SFP, SFP+ DWDM | Hundreds of kilometers |
GPON OLT SFP Class C++ 1490nm-TX/1310nm-RX 20km Transceiver
Optcore’s OSP2G-GNT-C++ is a high-performance class C++ GPON OLT SFP transceiver designed for point-to-multipoint (P2MP) Passive Optical Network (GPON) application. It is designed for 2488 Mbps downstream and 1244 Mbps upstream duplex data link transmission, high-speed burst mode TDM receiver/transmitters used. It is supplied in the SFP package with a single SC/UPC receptacle connector. It can fully support the GPON OLT application specified by the ITU-T G.984.2 class C++ specifications. This GPON OLT transceiver module consists of 1490nm continuous-mode 2.5Gbps DFB transmitter, 1310nm burst-mode 1.25Gbps APD receiver, Preamplifier and WDM filter in a high-integrated optical sub-assembly. It is a Class 1 laser product comply with the IEC 60825-1 and IEC 60825-2, and it is ROHS6 compliant.