This quick reference helps network engineers and data center techs interpret QSFP technical specs for 40G and 100G optics, with practical install checks you can use on Monday morning. You will also get troubleshooting patterns I've seen during leaf-spine bring-up and aging. The Cisco ® 40GBASE QSFP (Quad Small Form-Factor Pluggable) portfolio offers customers a wide variety of high-density and low-power 40 Gigabit Ethernet connectivity options for data center, high-performance computing 00networks, enterprise core and distribution layers, and service provider. It includes 40GBASE QSFP+ modules, 40G Converter modules, 40G DACs/AOCs and their breakout cables. Featured products such as QSFP-SR4-40G modules and QSFP-LR4-40G modules are also available for choice. 40G QSFP+ Transceiver Module Series include SR4, BIDI, CSR4, PIR4, LX4, IR4, LR4,PLR4 and ER4. Deployment flexibility with 800G (dual 400G), 400G, 100G, 50G, 40G, 25G, 10G or 1G modules. Interoperable with IEEE 40GbE LR4 and LRL4 for easier migrations from 10G to 40G and to single mode fiber 100G. QSFP 40G SR4 is a short-reach 40Gbps optical transceiver designed for high-density data center interconnects using multimode fiber and parallel optics. Long- and short-range optical connectivity options are suited to a wide range of data center and campus applications. The 40G ZR4 optical module, with its ultra-long-distance transmission capability of.