The QSFP-100G-LR4-C follows the IEEE 802.3ba 100GBASE-LR4 standard. Here's the complete breakdown:
| Parameter | Specification |
|---|---|
| Form factor | QSFP28 |
| Data rate | 100G (4 × 25.78125 Gbps) |
| Standard | 100GBASE-LR4 (IEEE 802.3ba) |
| Wavelength | 4-lane LAN-WDM: 1295.56 / 1300.05 / 1304.58 / 1309.14 nm |
| Fiber type | Single-mode fiber (SMF) |
| Connector | LC duplex |
| Max reach | 10 km |
| Power budget (typical) | ~7.3 dB |
| Max TX output power | ~+4.5 dBm per lane |
| Min TX output power | ~-4.3 dBm per lane |
| RX sensitivity | ~-10.6 dBm per lane |
| Max power consumption | ~4.5 W |
| Operating temperature | 0°C to +70°C (commercial grade) |
| DOM / DDM support | Yes |
| Encoding | 64B/66B |
One detail worth noting: the four LAN-WDM lanes span a tighter 1295–1309 nm window compared to CWDM4. That distinction matters when you're calculating link budgets on longer or higher-loss plant segments.
The QSFP-100G-LR4-C appears across Juniper's three main product families wherever 100G QSFP28 ports are present.
QFX Series — Data Center Switching
The QFX5100, QFX5110, QFX5120, QFX5200, QFX10002, and QFX10008 all use QSFP28 100G ports for spine-leaf interconnects, core uplinks, and inter-rack connectivity. LR4 is the natural choice when SR4's 100m reach on OM4 isn't enough and you're running SMF across a campus or between buildings.
EX Series — Enterprise Switching
EX4650 and EX9200 line cards with QSFP28 slots use LR4 for longer campus runs and WAN handoffs where SR4 simply isn't practical.
MX Series — Edge and Core Routing
MX204, MX240, MX480, MX960, and MX10003 line cards with QSFP28 interfaces rely on LR4 for peering links, metro interconnects, and handoffs to transport infrastructure.
Before committing to a purchase, cross-check the specific line card or PIC against Juniper's Hardware Compatibility Tool (HCT) at pathfinder.juniper.net. It lists tested and supported optics by platform and Junos version, and it's the authoritative reference for this kind of verification.
Juniper's approach to third-party optics is more permissive than Cisco's by default — but it's not frictionless.
Officially, Juniper supports only optics that have gone through its own qualification program. If you open a JTAC case with a non-Juniper optic in the chassis, the support engineer may ask you to swap it out before troubleshooting moves forward. That doesn't mean the module is causing the problem — but it's a real operational consideration for teams that need fast TAC engagement.
Earlier QFX platforms, particularly the QFX3500, had a well-documented behavior where non-Juniper optics would generate syslog warnings and, in some configurations, trigger port disable events or require explicit CLI overrides to bring the interface up. This was tied to how those platforms validated vendor ID strings in the EEPROM, and it's been discussed extensively on community.juniper.net across multiple Junos versions.
On current QFX5000 and MX platforms running modern Junos, that hard-lock behavior is generally not present. You may still see syslog messages about unrecognized optics, but the interface typically comes up and passes traffic without any manual intervention.
A coded compatible module is programmed with the vendor ID, part number string, serial number format, and DOM register map that the target platform expects to read from the EEPROM. When Junos queries the module's identification data, it sees values consistent with a Juniper-qualified optic.
This isn't spoofing in any meaningful sense — it's standard industry practice. The physical and optical specs are identical to the OEM; the EEPROM is simply programmed to match the platform's expected strings. A properly coded module passes DOM threshold queries, shows accurate TX/RX power readings in show interfaces diagnostics optics, and doesn't generate spurious syslog noise.
Not all compatible modules are equal. Here's what to check before placing an order.
1. Juniper-Specific Coding
Ask the supplier directly whether the module is coded for Juniper platforms. A generic 100GBASE-LR4 QSFP28 without Juniper coding may work on some platforms but will generate warnings or fail EEPROM checks on others.
2. DOM / DDM Support
DOM is non-negotiable for production networks. Confirm the module populates all standard DOM registers: TX power, RX power, temperature, voltage, and bias current. This data feeds your monitoring stack and is exactly what JTAC will ask about if you ever escalate a link issue.
3. Temperature Grade
Commercial grade (0°C to +70°C) covers most data center and enterprise switching environments. If you're deploying in an outdoor cabinet, industrial space, or extended-temp chassis, you need a module rated to at least -20°C or -40°C. Match the grade to your actual deployment conditions.
4. Warranty and Returns Policy
A reputable supplier offers at least a one-year warranty and accepts returns on DOA units. Batch failures happen even with quality manufacturing — your procurement terms should address this upfront.
5. Batch Testing Documentation
Ask whether the supplier performs per-batch optical testing — TX power, extinction ratio, sensitivity — before shipment. Suppliers who test and provide documentation give you real recourse if a batch underperforms.
6. Fiber Plant Compatibility
LR4's four LAN-WDM lanes require a clean SMF link. High connector loss, dirty ferrules, or aging splices can eat into the 7.3 dB power budget faster than expected. Verify your link loss budget before assuming 10 km is achievable end-to-end.
Juniper's QSFP-100G-LR4-C sourced through official channels or authorized distributors typically runs $400–$500+ per unit. For a spine-leaf deployment with 48 or 96 uplinks, that's a significant line item.
Third-party compatible modules coded for Juniper platforms are widely available at 60–90% below OEM pricing. The optical performance derives from the same IEEE 802.3ba specification. The difference is manufacturing origin and the OEM margin embedded in the Juniper part number.
For organizations that require full OEM support contracts and want zero JTAC friction, OEM pricing may be justified. For teams that manage their own optics inventory, have in-house testing capability, and are comfortable with Juniper's stance on third-party optics, compatible modules represent meaningful savings at scale.
HYTOPTODEVICE offers a Juniper-coded QSFP28 100G LR4 module tested on Juniper chassis. The module ships with Juniper-compatible EEPROM programming, full DOM support, and meets the 100GBASE-LR4 optical spec: four LAN-WDM lanes across 1295–1309 nm, LC duplex, 10 km on SMF, commercial temperature grade.
It's stocked alongside the full 100G QSFP28 range — SR4 for short-reach MMF, CWDM4 for 2km SMF with relaxed wavelength spacing, ER4 for 40km extended reach, and PSM4 for parallel SMF applications. If you're consolidating optics procurement across multiple link types in a Juniper environment, sourcing from a single supplier simplifies logistics and reduces per-unit cost at volume.
HYTOPTODEVICE also supports OEM/ODM and white-label options for resellers and system integrators who need custom labeling or private-brand packaging.
Q1: Is the QSFP-100G-LR4-C compatible with all Juniper QFX and MX platforms?
A: The QSFP28 form factor and 100GBASE-LR4 standard are supported across the QFX5000, QFX10000, EX4650, MX204, and MX series line cards with QSFP28 ports. Always verify the specific platform and Junos version against Juniper's Hardware Compatibility Tool before ordering.
Q2: Will a third-party compatible module trigger a port disable on Juniper switches?
A: On current QFX5000 and MX platforms running modern Junos, properly coded third-party modules typically bring up the interface without intervention. Older platforms like the QFX3500 had documented EEPROM validation behavior that could require CLI overrides. Coding accuracy is the key variable.
Q3: What does "Juniper-coded" mean for a compatible QSFP28 module?
A: It means the module's EEPROM is programmed with the vendor ID strings, part number identifiers, and DOM register mappings that Junos expects to read. This allows the platform to recognize the module without generating unsupported-optics warnings and ensures DOM data is accessible via standard show commands.
Q4: Does using a third-party optic void my Juniper hardware warranty?
A: Juniper's hardware warranty covers the switch chassis, not the optic. Using a non-Juniper optic does not void the chassis warranty. That said, JTAC may ask you to swap to a Juniper-qualified optic before engaging on a support case involving the optical interface.
Q5: What fiber type and connector does the QSFP-100G-LR4-C require?
A: Single-mode fiber (SMF, OS2) with LC duplex connectors. It is not compatible with multimode fiber. The four LAN-WDM transmit lanes operate across 1295–1309 nm, and the link budget supports up to 10 km under standard conditions.
Q6: How do I check DOM readings on a Juniper switch for this module?
A: Run show interfaces diagnostics optics in Junos. This returns TX power, RX power, temperature, supply voltage, and laser bias current per lane. A properly coded compatible module with DOM support will populate all fields correctly.
The QSFP-100G-LR4-C is a well-defined part number with a clear spec — but buying it at scale means understanding Juniper's optics compatibility behavior and knowing exactly what to ask a third-party supplier. Verify Juniper-specific coding, confirm DOM support, match the temperature grade to your environment, and check the supplier's testing and warranty terms before committing.
For teams ready to move past OEM pricing without giving up optical performance, explore HYTOPTODEVICE's Juniper-compatible 100G QSFP28 LR4 modules and the broader 100G range at hytoptodevice.com.
