FN-CABLE-QSFP28-4SFP28-X-BCC | Fortinet Compatible 100GB QSFP to 4 x 25GB SFP25G Direct Attach Breakout Cable | 1M to 5M

Q: Will this work in place of the Fortinet FN-CABLE-QSFP28-4SFP28-1, -3, or -5?
A: Yes. This cable is engineered to the same 25GBASE-CR standard with identical QSFP28 to 4x SFP28 form factor, 100G aggregate data rate, and passive twinax construction. It provides plug-and-play compatibility with Fortinet systems requiring the FN-CABLE-QSFP28-4SFP28 series, supporting both 100G QSFP28 and 25G SFP28 port configurations.

Q: Which Fortinet platforms support this breakout cable?
A: This cable works in Fortinet systems with QSFP28 or QSFP+ slots on one end and SFP28 or SFP+ slots on the other. The QSFP28 end requires a 100G-capable port, while the four SFP28 ends require 25G-capable ports (backward compatible with 10G and 1G SFP+ ports for reduced-rate operation).

Q: Can I run each of the four 25G channels at different speeds?
A: Yes, each SFP28 lane operates independently. The four channels can negotiate different rates (1G, 10G, or 25G) based on the connected device capability. The QSFP28 host port sees the aggregate bandwidth, so mixing a 25G, two 10G, and one 1G connection would present as 56G total to the QSFP28 interface.

Q: What is the maximum distance for passive copper breakout cables versus active optical?
A: This passive copper design supports up to 5 meters with the electrical signal propagating directly through copper pairs. For distances beyond 5 meters, an active optical breakout cable is required, as passive copper experiences excessive attenuation and crosstalk at 25Gbps signaling rates over longer runs.

Q: Does the extended temperature range affect signal quality or require special handling?
A: No special handling is required. The -40°C to 85°C rating reflects the cable's design for ruggedized environments, not a trade-off in performance. Twinax passive cables maintain consistent electrical characteristics across temperature because they rely on copper impedance rather than temperature-sensitive active components, making them more stable than transceiver-based solutions in thermal extremes.