SFP transceivers and DAC cables connect switches, routers, servers and network cards over fibre or short copper links. The category suits home labs, small offices and server rooms, with products from LANVIEW, Ubiquiti, HPE and Cisco, plus modules and direct attach cables from other network vendors.
Both product types plug into the same SFP-family ports, so the choice comes down to distance, speed and compatibility.
How to choose an SFP transceiver or DAC cable
Port type and speed. Match the module to the port on your device. SFP ports usually run at 1 Gbps, SFP+ at 10 Gbps and SFP28 at 25 Gbps, while QSFP ports handle 40 Gbps and above. An SFP+ port will often accept a 1 Gbps SFP module, but check the device manual first.
DAC cable or optical module. A DAC (direct attach copper) cable has the connectors permanently fixed to each end and suits short runs inside a rack or between neighbouring racks, typically a few metres. For longer distances, use two optical transceivers and fibre patch cables. DAC cables are generally cheaper and use less power, but they cannot be extended.
Fibre type and reach. Multimode modules (usually marked SR) are meant for shorter links within a building and work with multimode fibre. Single-mode modules (LR and similar) cover several kilometres. Both ends of a link must use the same fibre type and wavelength, and BiDi modules work only as a matched pair over a single fibre.
Compatibility and coding. Some switches and network cards only accept modules coded for their own brand. Check whether the product is listed for Cisco, HPE, Ubiquiti, MikroTik or NVIDIA equipment, or described as generic or multi-vendor, before ordering.
Cable length and connectors. Measure the path between the ports, including bends and slack, and choose a DAC cable slightly longer than that. Optical modules normally use LC duplex connectors, so your patch cables must match.
SFP and DAC brands in our range
- Ubiquiti: makes the UniFi network range, and its fibre modules and direct attach cables are designed for UniFi switches and gateways.
- HPE (including HP Enterprise): supplies modules and cables for its own ProLiant servers and Aruba switches, where part numbers matter for compatibility.
- Cisco: a major switch and router vendor, and its SFP modules are intended for Cisco platforms, which are often strict about module coding.
- MikroTik: known for RouterOS and affordable switches with SFP+ ports, and its S+ modules and cables are built for those devices.
- NVIDIA: owns the Mellanox networking line, so its cables and transceivers suit ConnectX network cards and high-speed data centre links.
- TP-Link: offers Omada and business switches with SFP slots, with modules intended for its own network gear.
- Digitus: a structured cabling brand, relevant when you are building fibre or copper links to a patching standard.
Also in our range: LANVIEW, Extralink, OEM by Sansec and RenewLink.
SFP transceiver and DAC cable FAQ
What is the difference between SFP and SFP+?
SFP modules are designed for speeds up to 1 Gbps, while SFP+ modules support 10 Gbps. Both have the same physical size, so they fit the same cage. Whether a port accepts both depends on the device, so check its specification.
Can I use a DAC cable instead of fibre?
Yes, if the two devices are close together. A DAC cable works well for links inside a rack or between adjacent racks, usually up to a few metres. Beyond that distance you need optical transceivers and fibre cable.
Will a third-party SFP module work in my switch?
Often it will, but some switches reject modules that are not coded for their brand. Look for a module listed as compatible with your switch vendor, or one with multi-vendor coding. Your switch documentation will state whether third-party modules are supported.
How far can an SFP transceiver reach?
Reach depends on the module type. Multimode SR modules typically cover from tens to a few hundred metres, depending on speed and fibre grade. Single-mode LR modules are made for several kilometres, and longer-range types go further still.
