In this guide
10GbE distance quick reference
| Technology | Medium | Common maximum | Interface |
|---|---|---|---|
| 10GBASE-T | Cat6 | Up to 55 m in the common structured-cabling model | RJ45 |
| 10GBASE-T | Cat6A | Up to 100 m channel | RJ45 |
| 10GBASE-SR | OM3 MMF | 300 m | SFP+ |
| 10GBASE-SR | OM4 MMF | 400 m | SFP+ |
| 10GBASE-LR | OS2 / G.652 SMF | 10 km | SFP+ |
| Passive SFP+ DAC | Twinax copper | Typically a few metres; check the exact assembly | SFP+ |
10GBASE-T over copper
10GBASE-T uses four copper pairs and an RJ45 interface. For new structured cabling, Cat6A is the straightforward choice when the requirement is 10 GbE to the conventional 100 m channel. Cat6 can also carry 10GbE, but the guaranteed reach is shorter and depends on the installed channel's performance, particularly insertion loss and alien crosstalk.
Do not confuse a patch-cable length with a 100 m channel. A structured cabling design includes horizontal cable, patch leads and connection hardware. The actual channel must meet the applicable category/class requirements.
OM3 and OM4 multimode fibre
10GBASE-SR uses 850 nm multimode optics. A common design limit is 300 m on OM3 and 400 m on OM4. OM4 has higher modal bandwidth, giving it more reach at 10GbE.
Multimode fibre is attractive for many building and data-room links because SR optics are widely available in SFP+ form. The actual optical channel still needs appropriate connectors, patching, polarity and loss budget.
Single-mode fibre
10GBASE-LR is designed for 10 km-class links over suitable single-mode fibre. Single-mode is therefore the normal choice when a 10GbE route exceeds multimode reach or when the site wants a fibre plant suitable for longer future links.
Longer-reach 10GbE optics such as ER and ZR-class products exist, but their exact distance, attenuation requirements and interoperability are transceiver-specific. Treat them as engineered optical links rather than simply applying a headline distance.
SFP+ DAC
Direct-attach copper assemblies plug directly into SFP+ ports and are commonly used for short switch-to-switch, switch-to-server or switch-to-storage links. They are compact and avoid separate transceivers, but their length and supported combinations are vendor-specific. Passive DAC should be treated as a short-reach solution rather than a replacement for structured cabling.
Choosing the medium
| Scenario | Starting point | Reasoning |
|---|---|---|
| Same rack | SFP+ passive DAC | Simple, low-cost short interconnect where both devices support it. |
| Up to 100 m new copper run | Cat6A / 10GBASE-T | Structured RJ45 cabling and conventional 100 m channel design. |
| 100–300 m fibre run | OM3 + 10GBASE-SR | Within common SR reach. |
| 300–400 m fibre run | OM4 + 10GBASE-SR | Extends SR reach compared with OM3. |
| Hundreds of metres to 10 km | OS2 + 10GBASE-LR | Single-mode provides substantially greater reach. |
Design checks before installation
- Confirm the exact Ethernet standard and optic part number at both ends.
- Check cable category, fibre type, polarity and connector type.
- For copper, account for the complete channel rather than only the permanent link.
- For fibre, check insertion loss, splice/connector count and the transceiver optical budget.
- Confirm minimum supported distances where applicable; some optics should not be used below their specified minimum without the appropriate design.
- Check switch/NIC compatibility, coding, FEC requirements and vendor support for third-party optics or DACs.
- Test the installed link at 10 Gb/s and retain the test results for handover.
Related Ingenix tools and references
Use the 10GbE Distance Calculator to test a proposed run, then see Cat6 vs Cat6A, OM3 vs OM4, SFP+ vs RJ45, fibre connector types, DAC vs AOC and multimode vs single-mode.
Sources: IEEE Ethernet physical-layer specifications and manufacturer transceiver datasheets should be treated as authoritative for a particular deployment. Cisco's current 10G SFP+ data sheet lists 300 m OM3, 400 m OM4 and 10 km LR examples; CommScope documents the 10GBASE-T Cat6/Cat6A cabling model.