Q1. What is a QSFPDD‑400G‑FR4 module?
A: The QSFPDD‑400G‑FR4 is a QSFP‑DD form-factor transceiver that supports 400 Gbps Ethernet over single‑mode fiber (SMF) using four CWDM wavelengths (1271/1291/1311/1331 nm) with a duplex LC optical interface.
Q2. What is the maximum supported transmission distance?
A: Supports up to 2 km over G.652 SMF when host-side forward error correction (FEC) is enabled, as per IEEE 802.3cu specification.
Q3. What connector and fiber type does it use?
A: Uses a duplex LC connector over single-mode fiber (9/125 µm SMF).
Q4. Is the module compatible across different brands?
A: Yes. It adheres to QSFP‑DD MSA and IEEE 802.3cu, and is compatible with vendors such as Cisco, Arista, Juniper, Huawei, FS.com, ProLabs, and Edge‑Core, provided the device accepts generic optics.
Q5. Is the module hot‑swappable?
A: Yes. The QSFP‑DD form factor supports hot-plug insertion and removal without powering down the host system.
Q6. Does it support breakout into lower-rate links?
A: Yes—commonly supports 4×100G DR1 breakout via appropriate cabling, allowing interoperability with 100G‑DR, FR, and LR optics up to specified distances.
Q7. Does QSFPDD‑400G‑FR4 support diagnostics (DDM/DOM)?
A: Yes. Supports digital diagnostic monitoring (CMIS/CMIS‑compliant) via I²C for monitoring power, temperature, voltage, and status.
Q8. What is the aggregate and per‑lane data rate?
A: Operates at a total of ~425 Gbps aggregate, using four 106.25 Gbps PAM4 lanes; internally interfaces with 8×50 Gbps PAM4 on electrical side (400GAUI‑8).
Q9. Typical power consumption?
A: Typically consumes ≤ 12 W, often around 10 W depending on variant and traffic load.
Q10. Operating temperature range?
A: Standard commercial modules operate from 0 °C to 70 °C; some specifications indicate up to –40 °C to +85 °C for storage or extended versions.
Q11. Which standards does it comply with?
A: Conforms to IEEE 802.3bs (400GBASE-SR8/FR4 spec), IEEE 802.3cu (400G‑FR4), QSFP‑DD MSA, 100G Lambda MSA FR4 spec, and 400GAUI‑8 / CEI‑56G‑VSR‑PAM4 electrical interface standard.
Q12. How to verify compatibility with my network device?
A: Confirm that your switch or NIC supports 400G‑FR4 QSFP‑DD optics, allows generic optics, and host-side FEC is enabled. Many vendors list part numbers like QDD‑400G‑FR4‑S for compatibility.
Q13. What are typical applications for this module?
A: Suitable for mid-range 400G data center interconnects, cross-building links, rack‑to‑rack backbone, and breakout into 100G channels in enterprise or cloud environments.
Q14. What is the optical power budget per lane?
A: Typical launch power per CWDM lane ~−3.3 to +3.5 dBm, with receiver sensitivity around < −7.7 dBm, sufficient for 2 km SMF link using FEC.
Q15. Are industrial or extended‑temperature variants available?
A: Yes. Some vendors offer modules with wider temperature support, though typical versions operate within 0‑70 °C, with storage tolerance up to –40 °C to +85 °C.