Zyxel QSFP100G-LR4 100GbE QSFP28 Transceiver
100GbEQSFP28 100GDuplex LC, single-mode fibre10 km, subject to optical-path limits
The Zyxel QSFP100G-LR4 is a single 100GbE QSFP28 optical transceiver for extending a supported switch connection over duplex single-mode fibre. It uses a duplex LC connector, 1310 nm wavelength and supports a maximum transmission distance of 10 km subject to optical-path limits. A suitable QSFP28 100G host port and compatible LR4 optics at both ends are required.
Best For: For network installations extending a supported 100GbE QSFP28 link over suitable duplex single-mode fibre, up to the stated optical distance and within path limits.
Before you order: Confirm the exact host supports this 100G QSFP28 module and check firmware, optic acceptance, host power and thermal allowance. A suitable duplex single-mode LC fibre path and compatible 100G LR4 optics at both ends are needed. Only one module is included; a remote module is not automatically needed if a suitable one is already installed. The 10 km figure is a maximum, not a guaranteed application throughput or included cable length. Fibre leads, host equipment and any needed remote optic are not listed as included. Removing the module interrupts the physical link.
What's in the Box
- One Zyxel QSFP100G-LR4 optical module
What It Means in Practice
- Use a supported QSFP28 100G port at the host and appropriate host support at both ends; cage shape alone does not establish compatibility.
- The link requires suitable duplex single-mode fibre with matching LC terminations and compatible 100G LR4 optics at the remote end. Existing suitable remote optics may be used.
- The 10 km maximum is subject to path loss, connectors, splices and matching optics; it does not state included cable length or guarantee application throughput.
- DDMI can expose operating readings and threshold alarms only where host firmware supports diagnostics; the module has no standalone web dashboard.
What Will Not Work
- Not for SFP, SFP+, SFP28 or ordinary RJ45 NIC ports; supported QSFP28 100G host-port and firmware acceptance are required.
- Not an SR4 MPO12 850 nm multimode, BiDi/single-strand or DAC product.
- Does not function as a complete switch or media converter and does not provide independent Internet access, routing, Wi-Fi or Ethernet-cable conversion.
- Fibre patch leads, host switches and any required remote optic are not listed as included.
- Removing the hot-pluggable module interrupts the physical link; zero downtime is not guaranteed. The listed reach is subject to optical-path limits.
Key Features
Duplex LC, single-mode optics
Uses duplex LC terminations over single-mode fibre, for a link design that matches those interfaces.
Up to 10 km transmission distance
A stated maximum for suitable optical paths; actual reach depends on path loss, connectors, splices and matching optics.
DDMI diagnostics
Can provide optical and module readings with threshold alarms when the host firmware supports them.
Listed Zyxel host support
The manufacturer matrix lists CX4800-56F and CX3800 Series for this exact LR4 model; verify the precise host and firmware.
Technical Specifications
| Manufacturer | Zyxel |
| Model | QSFP100G-LR4 |
| Manufacturer SKU | QSFP100G-LR4-ZZ0101F |
| EAN | 4718937649501 |
| Product type | 100GbE optical transceiver |
| Form factor / interface | QSFP28; supported host QSFP28 100G port required |
| Optical connector | Duplex LC |
| Fibre type | Single-mode fibre |
| Nominal wavelength | 1310 nm |
| Maximum transmission distance | 10 km; subject to path loss, connectors, splices and matching optics |
| Transmit optical power | -4.3 to +4.5 dBm |
| Receive optical power | -10.6 to +4.5 dBm |
| Digital diagnostics | DDMI supported; host firmware must support diagnostics |
| Monitored parameters | Temperature, received/transmitted optical power, bias current, supply voltage and threshold alarms, where supported by host firmware |
| Supply voltage | 3.135–3.465 V |
| Maximum current | 1360 mA |
| Maximum power consumption | 4.5 W |
| Power source | Compatible host cage; no external mains adapter or PoE injector required or supplied |
| Dimensions (W × D × H) | 118.4 × 19 × 9.8 mm |
| Weight | 45 g |
| Operating temperature | 0–70°C |
| Storage temperature | -40–85°C |
| MTBF | 4,863,340 hours at 25°C; statistical specification, not a warranty or promised service life |
| Hot-plugging | Hot-pluggable in a compatible host under its supported procedure; removing the module interrupts the physical link |
| Laser / safety | Class 1 laser; manufacturer lists 21 CFR 1040.10/1040.11 safety compliance |
| Manufacturer-listed compatible hosts | Zyxel CX4800-56F and CX3800 Series; CX3800 availability noted for Q4 2026. Verify exact model, port, firmware and current support. |
| Package quantity | Single pack; one module |
| Included item | One QSFP100G-LR4 optical module |
Frequently Asked Questions
What must the host support?
A supported QSFP28 100G port and appropriate firmware/optic acceptance are required. The manufacturer matrix lists Zyxel CX4800-56F and CX3800 Series; CX3800 carries a Q4 2026 availability note. Check the exact model, port, firmware and current support.
What else is needed for a link?
Suitable duplex single-mode fibre with matching LC terminations, compatible 100G LR4 optics at the remote end and appropriate host support at both ends. A second module is not included, but need not be purchased if a suitable remote optic is already installed.
Is a fibre cable included?
No fibre cable is listed as included. The package quantity is one module; other package extras are unverified.
Does the 10 km rating guarantee that reach in every installation?
No. It is the maximum stated transmission distance and is subject to optical-path loss, connectors, splices and matching optics.
Singular Expert Insight
It combines a 100GbE QSFP28 host interface with duplex LC single-mode optics and a 10 km maximum transmission distance in one module. Zyxel's current compatibility matrix lists the CX4800-56F and CX3800 Series for this exact model.
Buyer’s Guide
✓ Buy it if For network installations extending a supported 100GbE QSFP28 link over suitable duplex single-mode fibre, up to the stated optical distance and within path limits.
✕ Skip it if Confirm the exact host supports this 100G QSFP28 module and check firmware, optic acceptance, host power and thermal allowance. A suitable duplex single-mode LC fibre path and compatible 100G LR4 optics at both ends are needed. Only one module is included; a remote module is not automatically needed if a suitable one is already installed. The 10 km figure is a maximum, not a guaranteed application throughput or included cable length. Fibre leads, host equipment and any needed remote optic are not listed as included. Removing the module interrupts the physical link.
→ Also consider For a multimode/MPO link, consider an SR4 transceiver designed for that separate fibre and connector setup. This LR4 model is duplex LC single-mode and is not an SR4 substitute.