Cisco SFP-10G-ER-S — 10GBASE-ER S-Class SFP+ Transceiver, 1550nm, 40km
What it is
SFP-10G-ER-S is a Cisco 10 Gigabit Ethernet SFP+ optical transceiver designed for long-distance connections over single-mode fiber (SMF).
It operates at approximately 1550nm and supports 10GbE links of up to 40 kilometers over standard G.652 single-mode fiber, making it well suited to building-to-building, campus backbone, metro, and long-distance network links.
Why buyers pick SFP-10G-ER-S (plain English)
Up to 40km reach: Much longer distance than SR or LR optics, making it suitable for connecting sites across campuses or metropolitan areas.
Standard single-mode fiber: Works over widely deployed G.652 SMF, so it integrates easily into existing long-distance fiber infrastructure.
Compact SFP+ format: Fits directly into compatible Cisco 10G SFP+ ports without requiring a separate media converter.
LC fiber connector: Uses the familiar duplex LC interface common across enterprise fiber networks.
S-Class value: The S-Class version is intended for straightforward Ethernet applications where the additional protocol support of some full-feature Cisco optics is not required.
60-second spec box (SFP-10G-ER-S)
Ethernet standard
- 10GBASE-ER
- 10 Gigabit Ethernet
- S-Class transceiver
Fiber type
- Single-mode fiber (SMF)
- Designed for G.652 fiber
Maximum reach
- Up to 40 km
- Actual reach depends on fiber loss, connectors, splices, and overall optical budget
Wavelength
- Nominal 1550nm
- Operating wavelength range approximately 1530–1565nm
Connector
- Duplex LC
- Two-fiber transmit / receive connection
Form factor
- SFP+
- Hot-swappable
- Plugs into compatible Cisco SFP+ interfaces
Optical characteristics
- Transmit power: approximately -4.7 to +4.0 dBm
- Receive sensitivity down to approximately -15.8 dBm
- Suitable for long-reach 10GbE links
Compatibility
- Designed for supported Cisco switches, routers, and other platforms with compatible 10G SFP+ ports
- Platform compatibility should be checked before deployment
Protocol support
- 10 Gigabit Ethernet
- The SFP-10G-ER-S does not support FCoE
Where it fits (and when to choose something else)
Perfect for:
- Building-to-building fiber links
- Campus backbone connections
- Metro-area Ethernet links
- Data-center interconnects
- Long-distance 10GbE connections
- Sites separated by several kilometers of single-mode fiber
Choose something else if:
- You only need short multimode links → use SFP-10G-SR-S
- You need up to 10 km over single-mode fiber → use SFP-10G-LR-S
- You need around 80 km → consider SFP-10G-ZR-S
- You need industrial-temperature operation → consider SFP-10G-ER-I
- You require FCoE support → use an appropriate non-S-Class optic supported by your platform
TL;DR
SFP-10G-ER-S is a Cisco 10GBASE-ER SFP+ transceiver providing 10Gbps connectivity over single-mode fiber at 1550nm for distances up to 40 km — ideal for long-distance campus, metro, and inter-building Ethernet links.
