StarTech.com Cisco QSFP-40GE-LR4 Compatible QSFP+ Module - 40GBASE-LR4 - 40GbE Single Mode Fiber SMF Optic Transceiver - 40GE Gigabit Ethernet QSFP+ - LC 10km - 1270nm to 1330nm - DDM Cisco C4500, N7000, N7700

Product Overview

AI-generated summary

If you’re trying to light up a Cisco 40GbE QSFP+ port with SMF over distance, this is exactly the kind of “does the job without drama” module you buy. The fact it’s a StarTech-branded compatible QSFP+ that supports DDM and is aimed at older Cisco platforms (like the C4500/N7000/N7700 family) makes it a sensible value play—especially if OEM optics prices are making your refresh budget cry. At ~£124 ex-VAT, it’s likely to beat buying Cisco-branded equivalents outright, assuming your switch is one of the ones it’s meant to behave with.

That said, I wouldn’t buy this blind for a mixed environment. Compatible optics can be picky depending on IOS/NX-OS version, port configuration, and whether your vendor’s ecosystem does any optic/vendor enforcement. If your goal is “set-and-forget across multiple models and firmware baselines,” you’ll save time by validating compatibility with your exact switch software and optics policy first. Also, make sure your fibre plant is actually appropriate for the link distance you expect—10km is “works when the link budget and patching are right,” not a guaranteed free pass. Who should buy: teams with Cisco core/distribution gear in the listed families who need reliable 40GbE single-mode connectivity at sensible cost. Who should not: anyone with lots of unknown hardware/firmware variations who wants zero optic-related troubleshooting risk.