Juniper 400GBASE-DR4 QSFP-DD Transceiver — 500m Single-Mode Fiber

The Juniper QDD-400G-DR4 is a 400GBASE-DR4 QSFP-DD optical transceiver delivering 400GbE over single-mode fiber up to 500m at 1310nm via MPO-12 connector — Juniper-coded for use in Juniper QFX and PTX platforms supporting 400G QSFP-DD ports, providing high-density 400G SMF connectivity for data center spine, core routing, and hyperscale interconnect applications.

Key Features

• 400GBASE-DR4 QSFP-DD for 500m 400GbE over single-mode fiber using 4 x 100G DR lanes
• MPO-12 connector enabling 4x100G breakout via MPO-to-LC fan-out cables
• QSFP-DD (Double Density) form factor — two QSFP rows per port for 400G in standard QSFP footprint
• Juniper-coded (QDD-400G-DR4) for plug-and-play compatibility on Juniper 400G platforms
• IEEE 802.3bs 400GBASE-DR4 compliant for standards-based 400G SMF deployments

Product Specifications

• Part Number: QDD-400G-DR4
• Manufacturer: Juniper Networks
• Form Factor: QSFP-DD
• Speed: 400GbE (400GBASE-DR4)
• Wavelength: 1310nm (4-lane parallel SMF)
• Connector: MPO-12
• Fiber Type: Single-Mode Fiber (SMF, OS2)

Transceiver & Interface Specifications

• Max Distance: 500m over OS2 SMF
• Data Rate: 4 x 100Gbps parallel lanes
• TX Power: -4.0 to +1.0 dBm per lane
• RX Sensitivity: -9.0 dBm (min per lane)
• Power Consumption: Typically 10W
• DDM/DOM: Yes
• Operating Temperature: 0°C to 70°C (commercial)

Use Cases

• 400GbE spine-to-spine and spine-to-core SMF links in Juniper QFX hyperscale data centers
• 4x100GbE breakout via MPO-to-LC fan-out for 100G server or aggregation connections
• Service provider 400G core and peering interconnect on Juniper PTX platforms
• Campus or data center 400G inter-building links up to 500m over OS2 SMF

Compatibility

• Compatible with Juniper QFX and PTX platforms with QSFP-DD 400G port slots
• Requires OS2 single-mode fiber with MPO-12 connectors
• Supports 4x100G breakout via MPO-12 to 4x LC duplex fan-out cables
• IEEE 802.3bs 400GBASE-DR4 compliant — interoperable with other 400GBASE-DR4 QSFP-DD ports

Frequently Asked Questions

What is the difference between QDD-400G-DR4 and 740-085351?

Both are Juniper-genuine 400GBASE-DR4 QSFP-DD transceivers with identical optical specifications — QDD-400G-DR4 uses the alphanumeric part number format, while 740-085351 uses the numeric format. Both are fully interchangeable on supported Juniper 400G platforms.

Can the QDD-400G-DR4 support 4x100G breakout?

Yes — the MPO-12 connector supports 4x100G breakout via MPO-12 to 4x LC duplex fan-out cables. Each of the 4 parallel 1310nm lanes connects to a separate 100GBASE-DR SFP at the far end, enabling flexible 100G or 400G connectivity from a single QSFP-DD port.

What is QSFP-DD and how does it differ from QSFP28?

QSFP-DD (Double Density) adds a second row of 4 electrical lanes to the QSFP form factor, enabling 8 x 50Gbps or 8 x 25Gbps lanes for 400G or 200G operation. It is backward compatible with QSFP28 100G modules in QSFP-DD slots, but QSFP-DD modules cannot be inserted into standard QSFP28 ports.

The Juniper QDD-400G-DR4 brings 400GBASE-DR4 connectivity to Juniper's 400G QSFP-DD platforms — delivering 500m SMF reach, 4x100G breakout capability, and standards-compliant 400G operation for hyperscale data center spine, core routing, and service provider interconnect deployments.