A 10G SFP+ optic is chosen by fiber type and distance: SFP-10G-SR runs up to 300 m on OM3 multimode fiber, SFP-10G-LR runs 10 km on single-mode, SFP-10G-ER runs 40 km and SFP-10G-ZR about 80 km. For links inside a rack, a direct attach cable (DAC) usually replaces two optics and a patch lead.
Cisco 10G SFP+ optics compared
| Part number | Standard | Fiber | Wavelength | Reach |
|---|---|---|---|---|
| SFP-10G-SR | 10GBASE-SR | Multimode | 850 nm | 300 m on OM3, 400 m on OM4 |
| SFP-10G-LRM | 10GBASE-LRM | Multimode (also single-mode) | 1310 nm | 220 m on 62.5 um and OM2; 300 m on single-mode |
| SFP-10G-LR | 10GBASE-LR | Single-mode | 1310 nm | 10 km |
| SFP-10G-ER | 10GBASE-ER | Single-mode | 1550 nm | 40 km |
| SFP-10G-ZR | 10GBASE-ZR | Single-mode | 1550 nm | About 80 km |
Reach figures are from Cisco data sheets held in our catalog. All of these optics use duplex LC connectors.
SR: short reach, multimode
The SFP-10G-SR is the standard optic for 10G links inside a data center or building. It uses 850 nm light on multimode fiber: 300 m on OM3 and 400 m on OM4. Most server-to-switch and switch-to-switch links within a room or between nearby rooms use SR.
LR: long reach, single-mode
The SFP-10G-LR uses 1310 nm light on single-mode fiber and reaches 10 km. Use it between buildings, across a campus, or wherever the installed fiber is single-mode. LR also works on short single-mode links, so many teams standardize on it for all single-mode runs.
LRM: 10G over older multimode
The SFP-10G-LRM is a niche optic for older multimode cabling. It reaches 220 m on 62.5 um and OM2 fiber, where SR falls short. If you are upgrading an older building to 10G without replacing the fiber, LRM may avoid a recabling project.
ER and ZR: extended reach
- SFP-10G-ER runs 40 km at 1550 nm. Cisco notes that links under 20 km need a 5 dB attenuator, because the optic is powerful enough to overload a receiver at short range.
- SFP-10G-ZR runs about 80 km at 1550 nm. Cisco notes that ZR is not part of the IEEE standards, so check interoperability when the other end is a different brand.
ER and ZR are for metro and long-haul links, usually over leased or dark fiber.
BiDi: one fiber strand
BiDi optics send and receive on a single strand of single-mode fiber, using two wavelengths. They are always used in matched pairs. The SFP-10G-BXD-I (downstream) pairs with the SFP-10G-BXU-I (upstream) for links up to 10 km. Use BiDi when fiber strands are scarce.
S-Class and extended-temperature versions
Cisco sells several versions of the same optic. Suffixes in our catalog:
| Suffix | Meaning | Examples |
|---|---|---|
| (none) | Standard module | SFP-10G-SR, SFP-10G-LR |
| -S | S-Class: Ethernet-only, no FCoE support | SFP-10G-SR-S, SFP-10G-LR-S, SFP-10G-ER-S, SFP-10G-ZR-S |
| -X | Extended operating temperature | SFP-10G-SR-X, SFP-10G-LR-X |
If you do not run Fibre Channel over Ethernet, S-Class optics give the same Ethernet reach. Choose -X modules for hot or uncontrolled spaces.
10GBASE-T SFP+: copper RJ45
The SFP-10G-T-X adds an RJ45 port to an SFP+ slot. It reaches 30 m at 10G on Cat6A or Cat7 cabling, and 100 m at 100M or 1G. Copper SFP+ modules draw more power and run hotter than optics, so some switches limit how many you can install. Where you can, use a DAC or fiber instead.
DAC and AOC: inside the rack
For short links, a cable with fixed SFP+ ends on each side replaces two optics and a patch cable.
| Type | Cisco part numbers | Lengths |
|---|---|---|
| Passive twinax DAC | SFP-H10GB-CU1M, CU2M, CU3M, CU5M | 1, 2, 3, 5 m |
| Active twinax DAC | SFP-H10GB-ACU7M, ACU10M | 7, 10 m |
| Active optical cable | SFP-10G-AOC3M, SFP-10G-AOC10M | 3, 10 m |
DACs suit server-to-top-of-rack links. AOCs are thinner and lighter for longer in-row runs.
Other brands
Arista uses the same base names for the same standards, for example SFP-10G-SR, SFP-10G-LR and SFP-10G-ER. Arista also lists an SFP-10G-SRL (100 m on OM3, 150 m on OM4) and an SFP-10G-LRL (1 km single-mode) for shorter links. A Cisco-coded module and an Arista-coded module with the same name are different products; each is coded for its own switch.
For Dell servers, Dell lists its own 10GbE SFP+ LR transceiver (407-BBZV) for many PowerEdge models.
OEM vs compatible coding
Cisco switches read the module's EEPROM and expect Cisco or Cisco-coded optics. You have three options:
- OEM Cisco optics, for systems under Cisco support.
- Compatible optics, built to the same standard and coded for your switch.
- Generic optics, for switches and adapters that accept any standards-compliant module.
A link between two brands needs a module coded for each device at each end. Tell us both models and we will match them.
Checklist for your request
- Switch or adapter model at each end.
- Fiber type (OM3, OM4, older multimode, or single-mode) and distance.
- Standard, extended-temperature or S-Class.
- OEM or compatible coding.
- For DACs and AOCs: length, and the device at each end.
- Quantity, including spares.
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FAQ
What is the difference between SFP-10G-SR and SFP-10G-LR?
The SR runs over multimode fiber at 850 nm, up to 300 m on OM3 and 400 m on OM4. The LR runs over single-mode fiber at 1310 nm, up to 10 km. The two cannot be mixed on one link.
What is the difference between SFP-10G-SR and SFP-10G-SR-S?
Both are 10GBASE-SR optics with the same reach. The -S version is S-Class, which supports Ethernet only and not FCoE.
Can I connect an SR optic to an LR optic?
No. Both ends of a link must use the same standard and fiber type.
Do I need an attenuator with SFP-10G-ER?
Cisco notes that a 5 dB attenuator is needed for ER links shorter than 20 km.
Is a DAC better than two SR optics?
For links of a few meters, a DAC costs less and uses less power. For longer runs, or links through patch panels, use optics with structured fiber.