QSFP28 LR4 Transceiver

The QSFP28 LR4 transceiver is the fully specified 100G line in this catalogue, and its published specification sheet gives the figures a buyer needs to judge whether it fits a link: a 100G rate, a 1310nm wavelength, reach options of 10km and 20km, single-mode fiber, an aggregate bandwidth of 103.1Gb/s, power consumption below 3.5W, and an operating temperature range of 0 to 70 degrees Celsius. The published models are BT-QSFP28-LR4, BT-QSFP28-LR4-MPO and BT-QSFP28-20. The standards named on the product page are QSFP28 MSA and IEEE 802.3ba, with the interface designated 100GBASE-LR4. Those figures belong to this product alone and are not shared with any other transceiver on this site.

The 100G rate is the headline figure, but the reach options are what decide most purchases. The product page lists 10km over LC or MPO connectors and 20km over LC connectors. That distinction matters in practice: a campus backbone, a metro link between buildings, or a data-centre interconnect across a site will each sit at a different point on that range, and the connector choice follows the installed fiber plant rather than the other way round. A buyer should confirm the connector type and the reach option together during the inquiry, because the two options are not interchangeable.

The 1310nm wavelength places this module in the single-mode family. Single-mode fiber carries light in a single path down a narrow core, which is what allows a 10km or 20km link at 100G in the first place. Multimode fiber, by contrast, is a short-reach medium, and a module built for single-mode fiber will not perform over a multimode plant. If the installed fiber is single-mode, this module family is the right shape; if it is multimode, the 40G QSFP+ SR4 line or the SFP+ SR line is the closer match, and the choice should be made on the fiber actually in the ground.

Power consumption below 3.5W and an operating range of 0 to 70 degrees Celsius are the two figures that govern the thermal design of the installation. A 100G module draws real power, and a rack full of them draws a great deal of it; the published ceiling lets a buyer work out the cooling budget for a populated switch before ordering. The temperature range covers ordinary indoor installations, from a cooled data hall to a warmer wiring closet, but it does not extend to outdoor or unconditioned environments, and a buyer planning such an installation should raise it during the inquiry rather than assume the module will tolerate it.

The aggregate bandwidth figure of 103.1Gb/s reflects the four-lane construction of a 100G QSFP28 module: four lanes running in parallel, multiplexed onto the fiber. That construction is also why the QSFP28 form factor matters for density. A single QSFP28 port delivers 100G in roughly the space that once delivered 10G, which is what makes high-density 100G switching practical. The breakout guides on this site explain how a QSFP28 port can also be broken out to lower-speed ports where a mixed-speed design is needed, and the QSFP28 to SFP+ guide covers that option in detail.

On certification, the product page for this model states RoHS compliant. That statement is reported here as a product-page statement, not as a certificate reproduced on this site. Certificates are available upon request. No prices, minimum order quantities, delivery times or stock figures are stated for this model, because none have been published. Before ordering, confirm quantity, price and delivery time during the inquiry, together with the reach option and connector type your link needs.