Cisco SFP-10G-ER — 10GBASE-ER SFP+ (1550 nm, 40 km, SMF)

What it is: A 10 Gbps SFP+ optical transceiver for single-mode fiber (SMF) that runs 10GBASE-ER/EW at 1550 nm and reaches up to 40 km on G.652 fiber. Uses a duplex LC connector and supports DOM/DDM (digital diagnostics).

Why buyers pick SFP-10G-ER (plain English)

• Long-haul 10G without moving to DWDM—great for campus, metro rings, and stretched DC links up to 40 km.

• Standard SFP+ footprint: drops into Cisco switches/routers with SFP+ cages; dual-LC patching you already use.

• Real-time optics health via DOM (Tx/Rx power, temp, voltage).

60-second spec box

Optical / reach

• Wavelength: 1550 nm (EML laser)

• Fiber / connector: SMF (G.652), duplex LC

• Max distance: up to 40 km (assumes low-loss plant and proper power budget)

Performance & budgets (typical)

• Data rate: 10.3125 Gbps (Ethernet)

• Transmit power: –1 to +4 dBm

• Receive sensitivity: ≤ –16.5 dBm

• Power budget: ≈ 14 dB (check your splice/connector loss)

Electrical / power

• Supply: 3.3 V

• Module power: ~1.5 W max

Standards & features

• 10GBASE-ER / EW; SFF-8431/8432 compliant form factor; DOM/DDM supported.

Environment

• Operating temp: 0 to 70 °C (standard “-ER”); industrial “-ER-I” variant available if you need wider temp.

Where it fits (and when to step sideways)

• Perfect for: 10G uplinks between buildings/campuses or to remote POPs where LR (10 km) isn’t enough but DWDM/ZR is overkill.

• Use 10G-LR for ≤ 10 km on 1310 nm. Use 10G-ZR for ~80 km (with tighter loss budgets). Use ER-I if you need industrial temp.

Quick design tips (no-regret)

• Check the budget: sum fiber attenuation (~0.25 dB/km @1550 nm), splice + connector losses, then compare to ~14 dB module budget. Add margin for aging and temperature.

• Mind the Rx power on short runs: if the link is very short with low loss, you may over-power the receiver—insert an optical attenuator to keep within Rx spec. (Common on lab or MDF-to-MDF links.)

• Clean your LC ferrules: ER links are sensitive to connector contamination—use proper cleaning tools before testing.

TL;DR

SFP-10G-ER = 1550 nm, 40 km, SMF, LC duplex—a classic long-reach 10G SFP+ for campus/metro spans when LR can’t make it and ZR/DWDM would be overkill. ✔ Standard SFP+ slot, ✔ DOM, ✔ ~1.5 W power draw.

If you want, I can map this to your exact switch model (compatibility matrix + any minimum software notes) and sanity-check your fiber budget.