Cisco QDD-400G-ZRP-S
QSFP-DD transceiver module, coherent DCO, 400G-ZR+, Original Cisco
Product Highlights
As network operators scale to 400G and beyond, the challenge of extending high-capacity wavelengths across metro, regional, and long-haul distances — without deploying costly external transponder shelves — becomes critical. The Cisco QDD-400G-ZRP-S solves this by packing a full digital coherent optical (DCO) engine into a hot-pluggable QSFP-DD form factor.
This 400G-ZR+ transceiver complies with the OpenZR+ MSA, enabling standards-based interoperability across multivendor DWDM networks. It leverages a 7 nm coherent DSP ASIC combined with an ultra-narrow linewidth tunable laser and high-responsivity coherent receivers to deliver flexible line rates of 100G, 200G, 300G, and 400G using QPSK, 8-QAM, and 16-QAM modulation schemes. With full C-band tunability and support for both transponder and muxponder modes (1×400GE or up to 4×100GE), a single optic can address a wide range of deployment scenarios — from data center interconnect (DCI) edge links to amplified long-haul spans.
The QDD-400G-ZRP-S is the ideal choice for operators pursuing a Routed Optical Networking strategy, collapsing the IP and optical layers into a single device. It eliminates the need for external line-system transponders, simplifies sparing, and reduces total cost of ownership while delivering the longest reach in the Cisco 400G QSFP-DD coherent portfolio thanks to its high-performance O-FEC algorithm.
Features & Benefits
Flexible Line-Rate Modulation
The QDD-400G-ZRP-S supports QPSK, 8-QAM, and 16-QAM modulation at an ~60 GBaud symbol rate, enabling 200G, 300G, and 400G per-wavelength capacity respectively. It also supports 100G via QPSK at ~30 GBaud. This flexibility lets operators right-size capacity to the link distance and fiber conditions, maximizing spectral efficiency on shorter metro spans while extending reach on longer routes.
OpenZR+ Multivendor Interoperability
Compliant with the OpenZR+ MSA, this module interoperates with any standards-compliant coherent pluggable from other vendors. This eliminates vendor lock-in on the optical layer and simplifies multi-domain network designs. The OpenZR+ standard combines the best of OIF 400ZR and OpenROADM specifications to address 400G Ethernet-centric solutions beyond 120 km.
Extended Reach with O-FEC
The high-performance Open FEC (O-FEC) algorithm with 15% overhead and ~11.6 dB net coding gain enables this transceiver to achieve the longest transmission distances in the Cisco 400G QSFP-DD coherent portfolio. Amplified reaches extend well beyond 120 km at 400G, and even further at lower line rates — making it suitable for regional and long-haul deployments.
Full C-Band Tunability
Tunable across the entire DWDM C-band (191.3 THz to 196.1 THz), the QDD-400G-ZRP-S supports 100 GHz, 75 GHz, and 50 GHz channel grids. This enables dense wavelength packing on amplified line systems and provides maximum flexibility for wavelength planning across existing fiber infrastructure.
Transponder & Muxponder Modes
The module supports both 1×400GE transponder and muxponder configurations including 4×100GE, 3×100GE, 2×100GE, and 1×100GE client-side mappings. This allows operators to aggregate multiple lower-rate client signals onto a single coherent wavelength, maximizing fiber utilization and simplifying network design.
IP-over-DWDM Simplification
By integrating coherent DWDM optics directly into router QSFP-DD ports, the QDD-400G-ZRP-S enables a Routed Optical Networking architecture that collapses the traditional IP and optical transport layers. This eliminates external transponder shelves, reduces rack space and power consumption, and dramatically simplifies network operations and spare-parts inventory.
Deployment Scenarios
Data Center Interconnect (DCI) — Edge & Regional
Connect geographically distributed data centers over metro and regional distances with 400G coherent wavelengths directly from the router. The QDD-400G-ZRP-S supports amplified spans for DCI edge and regional interconnections, eliminating the need for standalone transponder equipment and reducing total cost of ownership.
Service Provider Metro & Long-Haul Core
Deploy flexible 100G–400G wavelengths across amplified DWDM line systems spanning metro rings and long-haul backbone routes. Adaptive modulation allows operators to optimize capacity vs. reach on a per-link basis, while OpenZR+ compliance ensures interoperability in multi-vendor optical networks.
Routed Optical Networking (RON)
Collapse the IP and optical layers by plugging coherent DCO optics directly into Cisco 8000, ASR 9000, or NCS series routers. This architecture eliminates external OTN/DWDM transponder shelves, reduces operational complexity, and enables end-to-end IP-layer management of the optical path using IOS XR or NX-OS.
Capacity Upgrade on Existing Fiber
Leverage full C-band tunability and dense channel spacing to add 400G wavelengths to existing fiber plants without re-cabling. The ability to run at 100G or 200G on longer spans ensures backward compatibility with legacy network segments while providing a clear upgrade path to 400G.
General
Performance
Optical
Reach (Amplified)
Electrical
Environmental
Standards & Compliance
Compatibility Notes
Supported Cisco Platforms
The QDD-400G-ZRP-S is supported on Cisco platforms with QSFP-DD 400G ports, including:
- Cisco 8000 Series Routers — IOS XR Release 7.3.x and later
- Cisco ASR 9000 Series Routers — IOS XR Release 7.3.x and later
- Cisco NCS 5500 / NCS 5700 Series Routers
- Cisco NCS 540 Series Routers
- Cisco Nexus 9000 Series (N9K-C93600CD-GX, N9K-C9316D-GX, N9K-9508/9504 with X9716D-GX line cards, N9K-9804/9808 with X98900CD-A and X9836DM-A line cards) — NX-OS Release 10.4(2)F and later
Note: On certain platforms and line cards, the QDD-400G-ZRP-S is supported only on specific (e.g., even-numbered) ports. Consult the platform-specific configuration guide for port restrictions.
Standards Compliance
- OpenZR+ MSA 2.0
- OIF-400ZR-02.0
- OIF-CMIS-05.2
- QSFP-DD Hardware Rev 6.3
- IEEE Std 802.3-2018
Downloads & Resources
Frequently Asked Questions
| Part Number | Product | Key Difference |
|---|---|---|
| QDD-400G-ZR-S | Cisco 400G ZR QSFP-DD DCO | OIF 400ZR compliant (400G only, no flexible modulation); optimized for point-to-point DCI up to 120 km at lower cost |
| DP04QSDD-HE0 | Cisco 400G ZR+ High-Power QSFP-DD DCO | Higher transmit power (0 dBm default) for extended unamplified reach; same flexible modulation as ZRP-S |
| CFP2-WDM-D-1HL | Cisco CFP2 Digital Coherent 200G | Larger CFP2 form factor supporting up to 200G coherent; suited for legacy platforms without QSFP-DD ports |