Q1. What is a QSFP‑DD‑400G‑DR4 module?
A: The QSFP‑DD‑400G‑DR4 is a QSFP‑DD form‑factor transceiver supporting 400 Gbps Ethernet over single‑mode fiber (SMF) via four parallel lanes, each carrying a PAM4‑modulated 100 Gbps optical channel at 1310 nm with an MPO‑12 connector
Q2. What is the maximum transmission distance supported?
A: Up to 500 m over G.652 single‑mode fiber when host‑side FEC (e.g., KP4) is enabled.
Q3. Which connector and fiber type does it use?
A: Uses an MPO‑12 connector over 8‑strand or more 9/125 µm SMF.
Q4. Is QSFP‑DD‑400G‑DR4 compatible across equipment brands?
A: Yes. It is MSA‑compliant and compatible with Cisco, Arista, Juniper, Huawei, Edge‑Core, ProLabs, FS.com, and other vendors whose hardware supports generic QSFP‑DD optics.
Q5. Can this module be hot‑swapped?
A: Yes. As a QSFP‑DD module, it supports hot‑plug insertion and removal without powering down the device.
Q6. Does QSFP‑DD‑400G‑DR4 support breakout into lower speeds?
A: Yes. It supports 4×100G DR1 breakout or 2×200G DR2 breakout (via host‑side capability) using appropriate MPO‑to‑LC or MPO‑to‑MPO breakout cables.
Q7. Does it support digital diagnostics (DDM/DOM)?
A: Yes. It supports CMIS / SFF‑8636 / SFF‑8679 diagnostic monitoring, with real‑time data via I²C for optical power, temperature, voltage, and module status.
Q8. What is the data rate per lane?
A: Supports up to 100 Gbps per lane (PAM4, 106.25 Gbps per lane), aggregating to ~425 Gbps optical bandwidth over 4 lanes.
Q9. What is typical power consumption?
A: Approximately < 10 W to max ~12 W, depending on vendor and temperature variant.
Q10. What is the operating temperature range?
A: Standard commercial modules support 0 °C to 70 °C; extended variants may go to –5 °C to +85 °C, and industrial versions to –40 °C to +85 °C.
Q11. Which standards does it comply with?
A: Compliant with IEEE 802.3bs (400GBASE‑DR4), QSFP‑DD MSA, 400GAUI‑8 / CEI‑56G‑VSR‑PAM4, and diagnostic protocols CMIS V4.0 / SFF‑8636 / SFF‑8679.
Q12. How can I verify compatibility with my equipment?
A: Ensure your system supports QSFP‑DD 400G DR4 optics and allows third‑party modules. Many vendors provide compatibility matrices and part‑number coding. Generic MSA‑compliant modules typically work across major platforms.
Q13. What are typical application scenarios?
A: Suitable for 400 GbE data center spine-leaf interconnects, rack-to-rack links, high‑density multimode deployments, and use in breakout to lower-rate 100G or 200G connections.
Q14. What is the optical power budget per lane?
A: Typical transmit power per lane: –2.9 to +4.0 dBm; receiver sensitivity: ≥ –5.9 dBm, allowing ~3 dB link budget for 500 m reach over SMF.