This article will give you an overview of the use cases for fiber-optic networking, some of the terms used in fiber networking, and suggestions for setting up a fiber network.
Once you understand the basic concepts, you can check out my Recommended Equipment section toward the bottom of the article.
The following are some common use cases for fiber networks in home or office environments.
Electrical Isolation From Lightning, Surges, and Static
Running copper Ethernet cables and coax cables outdoors can put your entire home or office network at risk for power surges from lightning strikes.
A single strike can trace its way through your home or office's coax and copper Ethernet network cables. In many cases, this can instantly destroy all of your computer and network hardware.
Electricity from lightning, power surges, and static electricity cannot transmit across a fiber-optic line. Because of this, electrical isolation via fiber networking becomes an excellent form of insurance for this risk.
Fiber to Ethernet media converters adapt between a typical RJ-45 copper Ethernet cable and fiber-optic cable. A pair of fiber to Ethernet media converters can create a beneficial electrical barrier when running Ethernet between buildings or to outdoor Power over Ethernet (PoE) devices such as cameras and Wi-Fi access points.
By decoupling the connection between devices with fiber-optic cable, fiber networking can also prevent electrical interference.
As I discuss in the Indoor vs. Outdoor Fiber Cable section, avoid any outdoor fiber-optic cable that uses a metal protective sheath to maintain electrical isolation. Fiber-optic cable with metal materials can negate any benefits of electrical isolation. You can, however, use a combination of indoor and outdoor fiber to maintain the electrical isolation.
Learn more about surge protection in my article Ethernet Surge Protection for Home Networks.
Long Cable Runs
Most copper Ethernet cables (e.g., Cat 6a or Cat 8) have a maximum length of 100 meters (328 feet). One hundred meters is quite long! However, suppose you find yourself in a situation in which you need something longer. In that case, fiber-optic cable offers much longer max lengths. The shortest range transceivers can reach 550 meters at 1 Gbps, while the longest range transceivers can reach 160 km (about 100 miles)!
Without a fiber solution such as a fiber to Ethernet media converter, or a coax solution such as Ethernet Over Coax MoCA Adapters, you would be limited to the range of copper Ethernet cable.
Cable Category | Max Speed and Distance |
---|---|
Cat 5e |
|
Cat 6a |
|
Cat 8 |
|
Coax (MoCA 2.5) |
|
OS2 Single-Mode Fiber |
|
OM4 Multi-Mode Fiber |
|
Custom High-Speed Networks
Switches and network adapters with SFP modules allow you to create custom high-speed Ethernet networks. For example, using QSFP+ fiber transceiver modules, you could achieve 40 Gbps speeds across a building. With traditional copper cabling, these would be limited to shorter distances.
Find QSFP+ Network Adapters on Amazon (affiliate link).
Find QSFP+ Transceivers on Amazon (affiliate link).
There are endless ways to configure a fiber-optic network, but here are a few simple ways to add fiber to your existing network.
Fiber to Ethernet Media Converter
A fiber media converter, also known as a fiber to Ethernet converter, allows you to convert typical copper Ethernet cable (e.g., Cat 6a) to fiber and back again. The typical use case for this is to either extend the transmission distance or to segment your network, protecting it from electrical surges.
Check out the Recommended Equipment section below for our recommended fiber-optic cables to pair with the media converter shown above.
10 Gbps fiber to Ethernet media converters aren't as common. If you're interested in achieving this configuration at a lower price point, you can create your own media converter. You can make a media converter by getting two fiber switches, such as the one listed below, along with two 10G RJ45 SFP+ transceivers.
Fiber Switches
A fiber-optic switch allows you to connect two or more fiber-optic cables to form a network. These can behave like a typical Ethernet switch.
With a fiber switch combined with a fiber network adapter, you could connect fiber directly to your desktop computer or server.
Note that the switch above is powered via PoE and would also need SFP+ transceivers. However, it has some pretty nifty features!
Fiber Network Adapter
A fiber network adapter allows you to connect fiber directly to your desktop computer or server. In this configuration, you may want to use a fiber switch. A fiber-optic cable between a fiber-optic network adapter and fiber-optic switch would provide the same electrical isolation as a fiber media converter.
Fiber network adapters allow for high-speed fiber connections directly to your computer without converting to copper Ethernet cable. Running a fiber connection to your computer is known as fiber-to-the-desktop (FTTD).
Fiber to Fiber Media Converters
Fiber to fiber media converters can convert between single-mode fiber (SMF) and multi-mode fiber (MMF) or between single fiber and dual fiber cable. We'll discuss each of these terms in more detail below.
Fiber-Optic Cable
Fiber-optic cable is a thin transparent tube made of silica that guides light waves and is used to transport data.
Fiber optic cables shouldn't be bent more than recommended by the manufacturer. Bending it more than recommended will increase attenuation as light escapes the core and can result in microfractures.
Fiber-Optic cables come in a variety of grades with varying levels of attenuation and maximum signal reach.
For multi-mode fiber, cable grades include OM1, OM2, OM3, and OM4.
OM3 and OM4 are the ideal choices when budget allows.
For single-mode fiber, cable grades include OS1 and OS2.
OS1 is best for indoor applications, and OS2 is best for outdoor applications.
To compare the max speeds of each cable type, see the Fiber Cable and Transceiver Max Distances section below.
Transceiver
- Fiber Transceiver
- An optical transceiver is a device that converts electrical signals into optical signals and vice versa. Fiber network devices often have interchangeable transceivers in varying form factors to support a range of speeds and applications.
SFP Transceiver Form Factors
Fiber-optic network devices often support hot-pluggable network interface modules to create a modular network design that meets specific needs. Hot-pluggable means that you can insert or remove an SFP module without shutting anything down.
Small form-factor pluggable (SFP) transceivers are compact hot-pluggable network interface modules. SFP modules exist for fiber and copper Ethernet cables, allowing conversion between cable types when combined in a switch.
While you can sometimes use SFP modules in SFP+ slots, other form factor combinations will typically need to use transceivers that match the slot's form factor.
The following are common form factors for fiber Ethernet transceivers and their supported max speeds:
Form Factor | Supported Speeds | Supported Media Type |
---|---|---|
SFP | 100 Mbps or 1 Gbps | Fiber or Copper |
SFP | 2.5 Gbps or 5 Gbps | Copper |
SFP+ | 10 Gbps | Fiber or Copper |
SFP28 | 25 Gbps | Fiber or DAC |
SFP 56 | 50 Gbps | Fiber or DAC |
QSFP | 4 Gbps | Fiber or DAC |
QSFP+ | 40 Gbps | Fiber or DAC |
QSFP28 | 50 or 100 Gbps | Fiber or DAC |
QSFP56 | 200 Gbps | Fiber or DAC |
QSFP-DD | 400 Gbps | Fiber or DAC |
- DAC
- Direct Attach Copper is a Twinax copper cable that integrates the SFP modules.
- Twinax
- Twinaxial cabling is similar to coaxial cable, except it uses two inner conductor wires instead of one.
Single-mode fiber (SMF) and multi-mode fiber (MMF) cables are used with SMF and MMF-specific optical transceivers.
- Single-Mode Fiber (SMF)
- Single-mode fiber (SMF) is a fiber-optic cable designed to carry a single "mode" of light. SMF has a narrow 9 µm core. SMF transceivers typically produce light for Single-Mode Fiber at 1310 nm and 1550 nm wavelengths.
- Suitable for longer distances of up to 160 km, but can also be used for short distances.
- Lower attenuation, with OS1 grade cables having a max attenuation of 1.0 dB/km and OS2 grade cables having a max attenuation of 0.4 dB/km. These attenuation levels are consistent across the 1310 nm and 1550 nm wavelengths.
- More expensive transceivers which use lasers and laser diodes.
- More expensive cable.
- Harder to terminate cable due to the smaller core (if you're terminating the cable yourself).
- Multi-Mode Fiber (MMF)
- Multi-mode fiber (MMF) is a fiber-optic cable designed to carry multiple "modes" of light simultaneously. MMF has a larger 50 µm core for OM1/OM2/OM3 and a 62.5 µm core for OM4. MMF transceivers can produce light for Multi-Mode Fiber at 850 nm and 1300 nm wavelengths.
- Suitable for shorter distances of up to 2 km.
- Lower-cost transceivers which use LED and VCSELs.
- Lower-cost cable.
- Higher attenuation, with OM1/OM2/OM3 grade cables having a max attenuation of 3.5 dB/km and 1.0 dB/km for the 850 nm and 1300 nm wavelengths, respectively. OM4 grade cables have a max attenuation of 2.5 dB/km and 0.8 dB/km for the 850 nm and 1300 nm wavelengths, respectively.
- Less expensive than single-mode fiber.
- Easier to terminate due to the larger core (if you're terminating the cable yourself).
The max distance of a fiber-optic connection depends on:
- The types of optical transceivers on each end of the cable
- The grade of cable
- The polish angle
of the cable end face (PC vs. UPC vs. APC)
- Whether single-mode fiber (SMF) or multi-mode fiber (MMF) is used
The following table describes the distances which can be reached by each grade of cable and Ethernet transceiver type.
OS1 (SMF) | OS2 (SMF) | OM1 (MMF) | OM2 (MMF) | OM3 (MMF) | OM4 (MMF) | |
---|---|---|---|---|---|---|
SX - 100 Mbps | 0.300 km | 0.300 km | 0.300 km | 0.300 km | ||
FX - 100 Mbps | 2 km | 2 km | 2 km | 2 km | ||
SX - 1 Gbps | 0.275 km | 0.555 km | 0.800 km | 0.880 km | ||
LX - 1 Gbps | 5 km | 5 km | 0.550 km | 0.550 km | 0.550 km | 0.550 km |
L - 10 Gbps | 10 km | 10 km | ||||
LRM - 10 Gbps | 0.220 km | 0.220 km | 0.220 km | 0.220 km | ||
LX4 - 10 Gbps | 10 km | 10 km | 0.3 km | 0.3 km | 0.3 km | 0.3 km |
E - 10 Gbps | 40 km | 40 km | ||||
S - 10 Gbps | 0.033 km | 0.082 km | 0.300 km | 0.450 km | ||
LR4 - 40 Gbps | 10 km | 10 km | ||||
SR4 - 40 Gbps | 0.1 km | 0.125 km | ||||
LR4 - 100 Gbps | 10 km | 10 km | ||||
SR4 - 100 Gbps | 0.07 km | 0.10 km |
There are even more transceiver types, although I don't have the breakdown by cable grade. Here are a few more:
- (MMF) SX+/MX/LSX - 1.25 Gbps - can reach up to 2 km
- (SMF) XD - 1–2.5 Gbps - can reach up to 40 km
- (SMF) ZX - 1–2.5 Gbps - can reach up to 80 km
- (SMF) ZX - 1–2.5 Gbps - can reach up to 80 km
- (SMF) BX10 - 1–2.5 Gbps - can reach up to 80 km
- (SMF) EZX - 1–2.5 Gbps - can reach up to 160 km
- (SMF) EX - 1–2.5 Gbps - can reach up to 120 km
Ethernet Transceiver vs. Fiber Channel
- Ethernet Transceivers
- Ethernet transceivers use the Ethernet protocol and are suitable for typical local area network (LAN) purposes. The transceiver distances listed above are for Ethernet transceivers.
- Fiber Channel (FC) Transceivers
- Fiber Channel (FC) transceivers use a high-speed block-level protocol primarily used for connecting storage to servers in data centers.
Single Fiber (BiDi) vs. Dual Fiber Transceivers
- Single Fiber (BiDi/WDM) Transceiver
- Single Fiber Transceivers are bidirectional (BiDi) transceivers that send and receive data using the same fiber cable. BiDi transceivers use a technology called Wavelength Division Multiplexing (WDM).
- More expensive and less common than dual fiber transceivers
- Uses one fiber strand
- Typically used with a single duplex connector
- Dual Fiber Transceiver
- Dual Fiber Transceivers use two strands for transmitting and receiving data.
- Less expensive than single fiber BiDi transceivers
- Uses two fiber strands
- Works with two simplex connectors or one duplex connector
- Dual fiber transceivers can also use BiDi/WDM communication to multiply throughput, which is the case for some QSFP+, QSFP28, and QSFP-DD transceivers.
SC vs. LC
SC vs. LC Connector
SC and LC are two of the most common fiber connectors used for terminating fiber cable.
The LC connector is considered a modern replacement for the SC connector and is growing in popularity.
The LC connector is half the size of an SC connector.
The LC uses a latch, while SC uses a locking tab.
Simplex vs. Duplex Connector
A duplex fiber-optic connector connects to two optical ports, whereas a simplex connector connects to a single optical port. A duplex connector is often used with a dual fiber transceiver.
You can use two simplex fiber-optic patch cables in place of a single duplex cable and vice versa.
A single simplex fiber-optic cable provides a single direction of communication when used with a dual fiber transceiver. However, you can also use a single simplex fiber-optic cable for bi-directional communication via a single fiber (BiDi) transceiver. A duplex fiber-optic cable allows for bi-directional communication by using a pair of fiber strands.
Duplex vs. Simplex Connector
PC vs. UPC vs. APC
Polishing a cable end face can minimize any air gap between fiber cables and components and improve return loss.
Return loss is a measure of the strength of the signal reflected from the end of the cable. A high return loss is desirable. The return loss can be affected by polishing fiber-optic cable in different ways (e.g., different angles).
PC (physical contact), APC (angled physical contact), and UPC (ultra physical contact) are different ways of polishing the fiber end face.
Both PC and UPC connectors do not use an angle, although UPC connectors use an increased curvature.
UPC and PC are interchangeable; replacing a cable of one type with the other will not damage components. The same is not valid for APC connectors and components.
UPC and APC connectors and transceivers should not be intermixed. Doing so can damage the transceiver.
Multi-Mode Fiber: PC vs. UPC
Most multi-mode fiber uses a PC polish, but a UPC polish can improve return loss further.
Single-Mode Fiber: UPC vs. APC
APC can be useful for sensitive applications where SMF wavelengths over 1500 nm are used. UPC is typically used for SMF wavelengths less than 1500 nm. You can still use UPC for SMF wavelengths above 1500 nm; however, its return loss will not be as good.
APC has a better return loss of -65 dB from back reflection than UPC's return loss of -55 dB.
Most single-mode fiber equipment uses UPC connectors, so I recommend sticking with that unless your equipment indicates that APC connectors should be used.
UPC vs. APC Back Reflection
Outdoor fiber-optic cables include additional insulation and protective layers, making them harder to break or damage.
However, it's important to note that outdoor fiber cables may use metal protective sheaths, making the line susceptible to lightning strikes. For this reason, if electrical isolation is a requirement for your project, you'll want to use a fiber-optic cable without metallic elements. However, keep in mind that you can use a combination of indoor and outdoor fiber to maintain the electrical isolation.
- Light Attenuation
- Light attenuation is the reduction in the intensity of a light beam as it propagates through a cable.
Light attenuation can be relevant in two ways. Suppose the signal level (i.e., light intensity) is too high due to the receiver being close to the transmitter. In that case, you may need an attenuator/pad to reduce the signal level.
Optical attenuators reduce the light intensity through a fiber-optic cable.
The signal level may not be high enough if a fiber cable is too long due to too much attenuation. In this case, you would need a higher-powered transceiver or shorter fiber cable.
Direct-attach cables combine the transceiver and cable into a single package. Direct-attach cables can simplify the wiring of short connections.
For optical cables, these are referred to as Active Optical Cables.
Be aware that if you use a Direct Attach Copper (DAC) cable, you won't have any of the electrical isolation benefits of using an optical cable. The reason for this is because DAC cables are not optical cables; they are copper Ethernet cables.
I've created a few recommended equipment lists based on different use cases:
- Extending or Isolating a Network with Fiber to Ethernet Converters
- Running 10 Gbps Fiber to Multiple PCs
- Creating a Custom 10 Gbps Fiber Network
Extending or Isolating a Network With Fiber to Ethernet Converters
10 Gbps Ethernet Extension via Fiber
- Two 10 Gbps media converters
10 Gigabit Fiber to 10G Copper UTP Ethernet Media Converter Check Price on Amazon Amazon Affiliate Link
- Two 10GBASE SFP+ MMF transceivers
10GBase-SR SFP+ Transceiver, 10G 850nm MMF, up to 300 Meters Check Price on Amazon Amazon Affiliate Link
- LC to LC OM3 MMF duplex fiber patch cable
Fiber Patch Cable - LC to LC OM3 10 Gigabit Multi-Mode Duplex 50/125 Check Price on Amazon Amazon Affiliate Link
1 Gbps Ethernet Extension via Fiber
- Two 1 Gbps media converters
Pair of 1.25G Media Converters, SFP Slot and SFP Modules, MMF, 850-nm, 550 meters Check Price on Amazon Amazon Affiliate Link
- LC to LC OM3 MMF duplex fiber patch cable
Fiber Patch Cable - LC to LC OM3 10 Gigabit Multi-Mode Duplex 50/125 Check Price on Amazon Amazon Affiliate Link
Running 10 Gbps Fiber to Multiple PCs
- 10GBASE fiber switch
MikroTik 5-Port Desktop Switch, 1 Gigabit Ethernet Port, 4 SFP+ 10Gbps Ports Check Price on Amazon Amazon Affiliate Link
- PoE injector to power the PoE switch
TP-LINK 802.3af Gigabit PoE Injector Check Price on Amazon Amazon Affiliate Link
- 10GBASE SFP+ MMF transceivers
10GBase-SR SFP+ Transceiver, 10G 850nm MMF, up to 300 Meters Check Price on Amazon Amazon Affiliate Link
- 10 Gbps PCIe network adapters
10 Gb PCI-E NIC Network Card, Single SFP+ Port Check Price on Amazon Amazon Affiliate Link
- LC to LC OM3 MMF duplex fiber patch cables
Fiber Patch Cable - LC to LC OM3 10 Gigabit Multi-Mode Duplex 50/125 Check Price on Amazon Amazon Affiliate Link
Creating a Custom 10 Gbps Fiber Network
- 10GBASE fiber switch
MikroTik 5-Port Desktop Switch, 1 Gigabit Ethernet Port, 4 SFP+ 10Gbps Ports Check Price on Amazon Amazon Affiliate Link
- PoE injector to power the PoE switch
TP-LINK 802.3af Gigabit PoE Injector Check Price on Amazon Amazon Affiliate Link
- 10GBASE SFP+ MMF fiber transceivers
10GBase-SR SFP+ Transceiver, 10G 850nm MMF, up to 300 Meters Check Price on Amazon Amazon Affiliate Link
- 10GBase-T SFP+ CAT.6a transceivers, if you want to attach to additional standard copper Ethernet devices
10GBase-T SFP+ Transceiver, 10G T, 10G Copper, RJ-45 SFP+ CAT.6a, up to 30 meters Check Price on Amazon Amazon Affiliate Link
- 10 Gbps PCIe network adapters
10 Gb PCI-E NIC Network Card, Single SFP+ Port Check Price on Amazon Amazon Affiliate Link
- LC to LC OM3 MMF duplex fiber patch cables
Fiber Patch Cable - LC to LC OM3 10 Gigabit Multi-Mode Duplex 50/125 Check Price on Amazon Amazon Affiliate Link
What Is Single-Mode vs. Multi-Mode SFP?
A single-mode SFP is a small form-factor pluggable (SFP) optical transceiver for single-mode fiber (SMF), which converts electrical signals into optical signals using a single mode of light. SMF SFPs are used for fiber-optic networking. A multi-mode SFP is also an SFP transceiver, but it is designed for multi-mode fiber (MMF), which uses multiple modes of light. SMF is ideal for longer distances, whereas MMF components can be lower cost and are ideal for shorter distances.
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