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

EdgeOptic's QSFP-100G-ER4L-S compatible is a Cisco coded 100GBASE-ER4 Lite QSFP28 transceiver built on the 100G-QSFP28-40 hardware platform. The module ships pre-programmed with the Cisco EEPROM values for the QSFP-100G-ER4L-S ordering code, so the optic identifies on Cisco IOS XE and NX-OS as the OEM transceiver. Cisco lists this part under both the integrated PID QSFP-100G-ER4L-S and the spare PID QSFP-100G-ER4L-S= (the trailing equals sign is Cisco's spare-part ordering convention); the EdgeOptic compatible covers either ordering form. Don't confuse it with the Juniper QSFP-100G-ER4L (no -S suffix), which is a different vendor SKU on a different host EEPROM.

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 campus backbone, metro DCI or service-provider access ring 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-S is supported on Cisco Nexus 9000, Catalyst 9500, Catalyst 9600 and ASR 9000 series platforms with QSFP28 ports. Verify the optic against the Cisco Optics-to-Device Compatibility Matrix at tmgmatrix.cisco.com for your specific switch or router model, line card and IOS XE / NX-OS release before deployment, as supported optic lists vary by hardware family and firmware revision. Cisco IOS XE and NX-OS validate transceiver vendor identifiers on insertion; with the Cisco coded EEPROM the module appears as a recognized optic in standard Cisco transceiver inventory output, and the service unsupported-transceiver workaround is not required.

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 IOS XE and NX-OS show-command inspection, model-driven streaming telemetry 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.