Juniper QSFP-100G-ER4L Compatible 100GBASE-ER4 Lite QSFP28 40km Module

EdgeOptic's QSFP-100G-ER4L compatible is a Juniper coded 100GBASE-ER4 Lite QSFP28 transceiver built on the 100G-QSFP28-40 hardware platform. The module ships pre-programmed with the Juniper EEPROM values for the QSFP-100G-ER4L ordering code, so the optic identifies on Junos as the OEM transceiver. Don't confuse it with Cisco's QSFP-100G-ER4L-S, which is a different vendor SKU on a different host EEPROM, or with the Arista QSFP-100G-ERL4 where the suffix letter order differs by vendor convention.

Optically the module conforms to the 100GBASE-ER4 Lite specification. Four LAN-WDM channels at 1295.56, 1300.05, 1304.58 and 1309.14 nm each carry 25.78125 Gbps NRZ, multiplexed onto one duplex LC single-mode fiber pair. The transmitter is an EML array; the receiver is an APD array, providing the additional sensitivity that distinguishes ER4 Lite from a standard LR4 PIN-receiver build. ER4 Lite is not an IEEE 802.3ba or 802.3bm subclause and is not a 100G Lambda MSA grade; it is a generic 100GBASE-ER4 Lite specification used across vendor catalogs.

Reach is 40km on G.652 SMF with host RS-FEC enabled and 30km on the same fiber without FEC. Optical budget is 22 dB with FEC, 18 dB without. Host-side FEC is the gating requirement for the 40km reach; the optic itself is transparent to FEC and contains no internal FEC engine. Engineers planning service-provider edge, metro core or DCI links between 30 and 40km should confirm the host port has RS-FEC available on the 100GE MAC and verify both ends match during commissioning. Without FEC the link will close at distances up to 30km on plant operating near typical 0.35 dB/km attenuation.

The QSFP-100G-ER4L is supported on Juniper MX series, PTX series and QFX10000 series platforms with QSFP28 ports. Verify the optic against the Juniper Hardware Compatibility Tool at apps.juniper.net/hct for your specific chassis, line card and Junos release before deployment, as supported optic lists vary by hardware family and firmware revision. Juniper KB33461 documents Junos releases where a 100GBASE-ER4 Lite interface did not come up on insertion; the HCT entry for QSFP-100G-ER4L lists the supported Junos releases per platform. Junos validates transceiver vendor identifiers on insertion, and with the Juniper coded EEPROM the module reports as a recognized optic, with full DDM telemetry visible through show interfaces diagnostics optics output.

QSFP28 MSA SFF-8665 and SFF-8636 management compliance covers the electrical and software interfaces. DDM/DOM telemetry exposes per-lane TX and RX optical power, module temperature, supply voltage and laser bias current to the host for Junos CLI inspection and SNMP polling. The duplex LC connector accepts standard SMF patch cords. Power draw is bounded at 4.5 W maximum; the commercial 0 to +70 degC case-temperature range covers central-office and metro POP environments. Connector hygiene matters at ER4 Lite reach budgets; inspect and clean both end-faces before turn-up to avoid attenuation that erodes the FEC margin.

Backed by 15+ years of EdgeOptic compatibility engineering across vendor optical platforms. Ships next business day from EU stock with a lifetime warranty. For BOM verification or volume pricing, contact our sales team.