Cisco QDD-400G-LR8-S
400G QSFP-DD Tranceiver, 400GBASE-LR8, Duplex LC, 10km Duple, Original Cisco
Product Highlights
As data centers and enterprise networks scale to 400G, selecting the right optic for inter-building and campus backbone links is critical. The Cisco QDD-400G-LR8-S is an original Cisco 400GBASE-LR8 QSFP-DD transceiver module engineered to deliver 400 Gbps of bandwidth over distances up to 10 km on standard G.652 single-mode fiber.
The module uses an 8-lane LAN-WDM architecture with PAM4 modulation, multiplexing eight 50 Gbps optical channels across wavelengths in the 1270 nm–1330 nm range through a single duplex LC connector. Multiplexing and demultiplexing are handled entirely within the device, while forward error correction (FEC) is performed on the host platform. This design delivers high spectral efficiency and reliable long-reach connectivity without requiring parallel fiber ribbon cables.
Compliant with IEEE 802.3bs and the QSFP-DD Multi-Source Agreement (MSA), the QDD-400G-LR8-S integrates Digital Optical Monitoring (DOM) for real-time visibility into link health. It is ideal for data center interconnect (DCI), campus backbone, service provider metro aggregation, and high-performance computing environments where 400G density and 10 km reach are essential. As a genuine Cisco optic, it is fully supported across Cisco's QSFP-DD-equipped switching and routing platforms.
Features & Benefits
400G LAN-WDM PAM4 Architecture
The QDD-400G-LR8-S carries the 400 Gigabit Ethernet signal over eight LAN-WDM wavelengths using PAM4 modulation, with each lane operating at 50 Gbps. Multiplexing and demultiplexing are managed within the module, simplifying the host design and reducing external component requirements.
10 km Single-Mode Fiber Reach
Supporting link lengths of up to 10 km over a standard pair of G.652 single-mode fiber, this transceiver bridges inter-building, campus, and metro-edge distances. The duplex LC interface keeps cabling simple and leverages existing SMF plant investments.
Hot-Pluggable QSFP-DD Form Factor
The QSFP-DD (Double Density) form factor delivers twice the lane count of QSFP28 in the same faceplate width, enabling higher port density on compatible Cisco platforms. Hot-pluggable installation means zero-downtime module changes during maintenance windows.
Digital Optical Monitoring (DOM)
Integrated DOM/DDM provides real-time access to critical operating parameters including optical transmit and receive power, temperature, voltage, and bias current. This enables proactive link health monitoring and faster troubleshooting.
IEEE 802.3bs Standards Compliance
Full compliance with IEEE 802.3bs 400GBASE-LR8, QSFP-DD MSA, and CMIS specifications ensures broad interoperability. Standards-based design protects your investment and simplifies multi-vendor network integration.
Deployment Scenarios
Data Center Interconnect (DCI)
Connect geographically separated data center facilities up to 10 km apart with 400 Gbps links over existing single-mode fiber infrastructure. The duplex LC interface minimizes fiber count while the LR8 reach covers typical metro DCI distances.
Enterprise Campus Backbone
Upgrade campus core-to-distribution links to 400G to support growing east-west traffic from virtualization, unified communications, and cloud workloads. The 10 km range easily spans multi-building campus environments.
Service Provider Metro Aggregation
Aggregate multiple 100G or lower-speed access rings into a 400G metro backbone. The standards-based LR8 optic provides the reach and density needed for cost-effective service provider network scaling.
High-Performance Computing (HPC) Clusters
Deliver the low-latency, high-bandwidth fabric interconnects that HPC and AI/ML training clusters demand. The 400G capacity supports massive parallel data flows between compute and storage nodes across facility-scale distances.
General
Performance
Optical
Electrical
Environmental
Compliance
Compatibility Notes
The Cisco QDD-400G-LR8-S is designed for use in QSFP-DD ports on compatible Cisco platforms. Verified compatible platforms include (but are not limited to):
- Cisco 8000 Series: 8201-32FH, 8201-SYS, 8202-SYS, 8800-LC-36FH
- Cisco ASR 9000 Series: ASR-9903, A9K-20HG-FLEX, A9K-8HG-FLEX line cards
- Cisco Nexus 3000 Series: N3K-C3408-S, N3K-C3432D-S
Note: This is a QSFP-DD module and is not compatible with OSFP ports. FEC must be enabled on the host platform. Always verify transceiver support in the Cisco Transceiver Compatibility Matrix for your specific IOS-XR or NX-OS software release.
Downloads & Resources
Frequently Asked Questions
| Part Number | Product | Key Difference |
|---|---|---|
| QDD-400G-LR4-S | Cisco 400G QSFP-DD LR4 | Uses 4×100G CWDM4 lanes (vs. 8×50G LAN-WDM); same 10 km reach but different channel architecture — LR4 and LR8 are not interoperable |
| QDD-400G-FR4-S | Cisco 400G QSFP-DD FR4 | Shorter 2 km reach over SMF with 4 CWDM lanes; lower cost option for intra-campus or intra-facility links |
| QDD-400G-DR4-S | Cisco 400G QSFP-DD DR4 | 500 m reach over parallel SMF with MPO-12 connector; ideal for short intra-DC spine-leaf connections |
| QDD-400G-LR8-S-40 | Cisco 400G QSFP-DD ER8 | Extended 40 km reach variant using the same 8-lane LAN-WDM architecture; for longer metro/DCI spans |