Copper RJ45 SFP

Copper RJ45 SFP · 21 models

Copper RJ45 SFP and SFP+ Transceiver Modules

Copper RJ45 SFP transceivers in 1000BASE-T and 10GBASE-T builds, reaching 100 m over Cat5e, Cat6 or Cat6a twisted pair. Specifications and enquiry.

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Buying guide

What this family covers.

A copper RJ45 SFP puts a twisted-pair Ethernet port into a fibre cage. It is the usual answer when a switch has run out of built-in copper ports, when a single device close to the rack needs to be connected without running fibre, or when an uplink has to reach equipment that only offers an RJ45 interface. Mechanically the module is an ordinary SFP or SFP+, hot-pluggable and supplied from 3.3 V, but instead of a laser it carries a copper PHY that does the Ethernet signalling.

This category covers two families. The 1000BASE-T modules auto-negotiate 10, 100 and 1000 Mb/s and reach 100 m over Cat5e or Cat6 cable, drawing under 0.4 W, which keeps them viable in densely populated switch chassis. The 10GBASE-T modules are SFP+ parts that reach up to 100 m over Cat6a or Cat7 cable and are listed in 30 m, 80 m and 100 m reach classes; several also auto-negotiate down through 5G, 2.5G, 1G and 100 Mb/s for mixed access networks. Digital diagnostics are supported on the 10G parts and on some of the Gigabit parts.

The two things that decide the model are the cabling installed and the power and heat the host can absorb. Copper PHYs consume far more power than optics at 10G, and the shorter reach classes exist precisely because they run cooler.

  • Cat5e or Cat6 for Gigabit, Cat6a or Cat7 for 10GBASE-T
  • Shorter reach classes at 10G draw less power and run cooler
  • Check the switch supports copper modules in the chosen ports
  • Multi-rate parts help where 2.5G and 5G devices share a switch

Models

21 listed Copper RJ45 SFP products.

Filter the family, then open a model for the full specification table, illustrations and ordering information.

Category

Data rate

Form factor

Media

Listed reach

116 of 116 products

Selection

Choosing within this family.

Copper SFP variants in this range and the link each one suits.

VariantRatesTypical reachCablingWhere it fits
1000BASE-T SFP10 / 100 / 1000 Mb/s100 mCat5e or Cat6Adding copper ports to a fibre switch
1000BASE-T SFP, low power10 / 100 / 1000 Mb/s100 mCat5e or Cat6Dense chassis where power budget is tight
10GBASE-T SFP+, 30 m class10 Gb/s30 mCat6a or Cat7In-rack and adjacent-rack server links
10GBASE-T SFP+, 80 m class10 Gb/s80 mCat6a or Cat7Floor distribution within a building
10GBASE-T SFP+, 100 m class10 Gb/s100 mCat6a or Cat7Full-reach structured cabling runs
Multi-rate 10GBASE-T SFP+10G / 5G / 2.5G / 1G100 mCat6aMixed-speed access and wireless uplinks
Auto-negotiating 10GBASE-T SFP+10G / 1G / 100 Mb/s100 mCat6a or Cat7Access switches serving legacy devices

Listed values describe the published range. Confirm the exact model datasheet, host coding and installed link before ordering.

Before you order

What to confirm.

Power and heat in the cage

A 10GBASE-T PHY does a large amount of digital signal processing and dissipates several watts, far more than an optical module in the same slot. Some switches limit how many copper modules can be fitted, restrict them to particular ports, or require spacing between them. Check the switch documentation for that limit before filling a line card, and prefer the shortest reach class that covers the link, since a 30 m part runs cooler than a 100 m one. Adequate airflow in front of the ports matters as well.

Cabling grade sets the real reach

The reach printed on a 10GBASE-T module assumes a properly installed Cat6a or Cat7 channel. Cat6 can carry 10G over shorter distances but is sensitive to alien crosstalk in dense bundles, and Cat5e is not a 10G medium at all. For Gigabit modules, Cat5e or Cat6 is fine to 100 m. If the cabling has not been certified, test the channel before assuming the link will make its rated distance, particularly where the run shares a bundle with many other cables.

Host support and auto-negotiation

Not every SFP or SFP+ port accepts a copper module, and some platforms support them only in named ports or only at particular speeds. Copper modules also rely on auto-negotiation with the far end, which can be disabled on older devices, so a port that stays down is often a negotiation setting rather than a faulty module. Confirm support in the switch documentation, confirm the coding the platform expects, and check the speed and duplex configuration at both ends.

Latency and where copper is the wrong answer

A 10GBASE-T PHY introduces more latency than an optical link or a direct attach cable because of the block coding and equalisation it performs. For most enterprise traffic this is irrelevant, but for storage fabrics and latency-sensitive clustering it is a reason to use a direct attach cable or optics instead. Copper modules are best used where twisted pair is already installed or where the endpoint has no fibre interface, rather than as a default choice inside a rack.

FAQ

Copper RJ45 SFP questions.

Will a copper RJ45 SFP work in any switch?

Not always. The module is mechanically a standard SFP or SFP+, but the host has to support copper modules in that port, and some platforms restrict them to particular ports or limit how many can be used because of power and heat. Check the switch documentation for supported module types, confirm the coding the platform expects, and check any limit on the number of copper modules per line card.

What cable do I need for a 10GBASE-T SFP+ module?

Use Cat6a or Cat7 for the full 100 m. Cat6 can carry 10G over shorter distances but is more exposed to alien crosstalk in dense bundles, and Cat5e is not suitable for 10G. Where the channel has not been certified, test it before relying on the rated distance. For 1000BASE-T modules, Cat5e or Cat6 carries the full 100 m without difficulty.

Why are there 30 m, 80 m and 100 m versions of the same module?

Reach and power consumption are linked in a copper PHY. A module built for 30 m does less signal processing and dissipates less heat than one built for 100 m, which matters when several are fitted in the same chassis. If the link is short, the shorter class is the better engineering choice. Order the longer class only where the cable run genuinely needs it.

Can I use a copper SFP for a 2.5G or 5G device?

Some of the 10GBASE-T modules in this range auto-negotiate down through 5G, 2.5G, 1G and 100 Mb/s, which suits access switches serving wireless access points and multi-rate devices. Not every part supports every rate, so check the specification of the specific model and confirm that the switch port also supports the intermediate rates rather than only 1G and 10G.

Related families

Also worth comparing.

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