Q1. What is a QSFP‑DD‑400G‑SR8 module?
A: The QSFP‑DD‑400G‑SR8 is a QSFP‑DD transceiver module supporting 400 Gbps Ethernet over multimode fiber (MMF), using eight parallel PAM4 lanes at 850 nm, with an MTP/MPO‑16 connector.
Q2. What is the maximum transmission distance?
A: Up to 70 m over OM3, and up to 100 m over OM4/MMF, when host-side FEC is enabled.
Q3. What connector and fiber type does it use?
A: Uses an MTP/MPO‑16 connector over 50/125 µm multimode fiber (OM3/OM4/MMF).
Q4. Is QSFP‑DD‑400G‑SR8 compatible with equipment from different brands?
A: Yes. It is MSA-compliant, with support across Cisco, Arista, Juniper, Huawei, ProLabs, EdgeOptic, QSFPTEK, etc., as long as host devices support QSFP‑DD optics.
Q5. Does the module support hot-swapping?
A: Yes. Being a QSFP‑DD module, it supports hot-pluggability, allowing plug-in and removal without powering down host equipment.
Q6. Can it be used for breakout into lower rates?
A: Yes—it supports breakout into 8×50 GE lanes or 2×200 GE lanes, depending on host support, via compatible breakout cables.
Q7. Does QSFP‑DD‑400G‑SR8 support diagnostic monitoring (DDM/DOM)?
A: Yes. Supports DDM/DOM capabilities via CMIS/ I²C interface, offering real‑time data for power, temperature, voltage, etc.
Q8. What is the aggregate and per-lane data rate?
A: Provides up to 425 Gbps aggregate via eight lanes of 53.125 Gbps (PAM4) each.
Q9. What is the typical power consumption?
A: Typically consumes up to ≈8 W to 11 W, depending on vendor and traffic conditions.
Q10. What is the operating temperature range?
A: Standard commercial range is 0 °C to 70 °C. Extended or industrial variants may support wider ranges up to 85 °C.
Q11. Which standards and protocols does it comply with?
A: Complies with IEEE 802.3bs (400GBASE‑SR8), QSFP‑DD MSA, 400GAUI‑8 / CEI‑56G‑VSR‑PAM4, and CMIS V4.0 / SFF‑8636/8679.
Q12. How to verify compatibility with networking equipment?
A: Ensure your switch or NIC supports QSFP‑DD 400G SR8 optics, third‑party optics, and host‑side FEC. Most MSA‑compliant modules work universally across brands.
Q13. What are typical application scenarios?
A: Used for 400 Gbps data center spine/leaf links, high-density rack interconnects, or breakout into 50G/200G lanes in multimode fiber environments.
Q14. What is the optical power budget per lane?
A: Typical Tx launch power ranges from –6.5 to +4 dBm, and Rx sensitivity ≥ –8.4 dBm, providing >1.9 dB optical budget for 100 m OM4.
Q15. Are industrial or extended variants available?
A: Yes. While standard modules support commercial ranges, options with extended or industrial temperature specs up to –40 °C to +85 °C are available from many vendors.