Match both host ports, connector type and the actual cable route for short links.
The practical distinction
Length is part of an assembly specification, not just a delivery preference. Changing a DAC or AOC length changes the item being ordered and can change host support. A cable that fits the rack in a drawing may still be too short after real routing and service loops.
What the product details tell you
- 10G SFP+, 40G QSFP+ and 100G QSFP28 describe different interface families. Check both ends and the host support list.
- Keep DAC and AOC length suffixes such as 3M, 5M and 7M. Required route length includes service loops and bends.
- QSFP-40G-SR-BD uses a duplex multimode LC link. It is not a single-mode single-fiber module and should not be described as a 100G dual-rate optic.
Applying it to a project
Measure the installed path including bends, rack movement and service access. Choose supported direct-attach or optical links and label both ends. For pluggable optics, confirm fiber type and patching rather than selecting on distance alone.
Checks that resolve the uncertainty
- Verify exact cable lengths, host identifiers and connector fit.
- Test link mode, error counters and optical diagnostics where available.
- Check strain relief, bend radius and access for replacement.
Related products
Topic associations; verify the complete configuration before ordering.
- Cisco QSFP-40G-SR-BD 40G Short-Reach Duplex-Fiber BiDi Transceiver
- Cisco QSFP-H40G-CU3M-RF 40G 3m Passive DAC Cable
- Cisco QSFP-H40G-CU5M-RF 40G 5m Passive DAC Cable
- Cisco SFP-H10GB-CU5M-RF 10G 5m Passive DAC Cable
- Cisco SFP-H10GB-CU3M-RF 10G 3m Passive DAC Cable
- Cisco QSFP-H40G-AOC5M-RF 40G 5m Active Optical Cable
- Cisco QSFP-H40G-AOC7M-RF 40G 7m Active Optical Cable
- Cisco QSFP-100G-CU3M-RF 100G 3m Passive DAC Cable
- Cisco QSFP-H40G-AOC1M-RF 40G 1m Active Optical Cable
- Cisco QSFP-H40G-AOC2M-RF 40G 2m Active Optical Cable
- Cisco QSFP-H40G-AOC3M-RF 40G 3m Active Optical Cable