QDD-400G-FR4-S – 400G FR4 QSFP-DD – Duplex LC SMF – 2km Reach
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QDD-400G-FR4-S Description
QDD-400G-FR4-S is a Cisco 400G QSFP-DD FR4 optical transceiver in the Cisco QSFP-DD 400G module family for native 400GE links between Cisco QSFP-DD ports over duplex single-mode fiber. It uses a duplex LC PC/UPC interface, supports up to 2 km over G.652 SMF, follows 400GBASE-FR4 requirements under IEEE 802.3cu, carries the 400G signal across four CWDM optical wavelengths, and relies on FEC performed on the host platform, making it a fit for mid-reach data center, core, or aggregation fiber paths that need LC duplex 400G optics instead of parallel MPO cabling.
Quick Specs
|
Parameter |
Specification |
|---|---|
|
Product ID |
QDD-400G-FR4-S |
|
Product type |
400GBASE-FR4 QSFP-DD optical transceiver |
|
Form factor |
QSFP-DD |
|
Host interface |
Cisco QSFP-DD 400G port |
|
Ethernet rate |
400 Gigabit Ethernet |
|
Connector type |
Duplex LC PC/UPC |
|
Fiber type |
Single-mode fiber |
|
Fiber standard |
G.652 |
|
Maximum reach |
2 km |
|
Nominal wavelengths |
1270, 1290, 1310, and 1330 nm |
|
High-speed electrical interface |
400GAUI-8/CEI-56G-VSR-PAM4 |
|
Maximum supported insertion loss |
4 dB |
|
Maximum power consumption |
12 W |
Application Scenarios
QDD-400G-FR4-S is a fit for Cisco QSFP-DD ports when the fiber plant is duplex single-mode fiber and the measured route stays within Cisco’s 2 km FR4 reach. It keeps the cabling plan on LC duplex patching instead of MPO-12 parallel SMF.
For 400G links that are too long for DR4’s 500 m reach but do not need LR4’s 10 km distance, this FR4 optic can keep the order aligned with a shorter SMF loss budget. Check the remote optic, patch panels, and available 4 dB insertion-loss allowance before approval.
Keep QDD-400G-FR4-S separate from LR4, DR4, 4x100G FR, and SR4.2 spare pools. Similar part numbers can hide different connectors, reach limits, fiber media, and native-versus-breakout behavior.
Product Comparison
|
Parameter |
QDD-400G-FR4-S |
QDD-4X100G-FR-S | ||
|---|---|---|---|---|
|
Product type |
400GBASE-FR4 QSFP-DD transceiver |
400GBASE-LR4 QSFP-DD transceiver |
400GBASE-DR4 QSFP-DD transceiver |
4 x 100GBASE-FR1 QSFP-DD transceiver |
|
Connector type |
Duplex LC PC/UPC |
Duplex LC PC/UPC |
MPO-12 APC |
MPO-12 APC |
|
Fiber type |
Single-mode fiber |
Single-mode fiber |
Single-mode fiber |
Single-mode fiber |
|
Cable topology |
Duplex SMF |
Duplex SMF |
Parallel SMF |
Parallel SMF |
|
Native link reach |
2 km |
10 km |
500 m |
2 km per 100G lane |
|
Operating mode |
Native 400GE FR4 |
Native 400GE LR4 |
Native 400GE DR4 with 4 x 100GE breakout support |
4 x 100GBASE-FR1 breakout |
|
Nominal wavelengths |
1270, 1290, 1310, and 1330 nm |
1270, 1290, 1310, and 1330 nm |
1310 nm |
1310 nm |
|
Nominal data rate |
425 Gbps |
425 Gbps |
425 Gbps |
4 x 100GE |
|
Maximum supported insertion loss |
4 dB |
6.3 dB |
3 dB |
4 dB |
|
Maximum power consumption |
12 W |
12 W |
12 W |
12 W |
- QDD-400G-FR4-S is the LC duplex single-mode option for a native 400GE link with Cisco’s documented 2 km FR4 reach.
- QDD-400G-LR4-S keeps the same LC duplex fiber style but extends the reach to 10 km, so it should be reserved for longer or higher-loss SMF paths.
- QDD-400G-DR4-S and QDD-4X100G-FR-S use MPO-12 parallel SMF and belong in a different patching or breakout design.
- QDD-400G-SR4.2-BD is a multimode MPO option and should not replace an FR4 single-mode line item without changing the fiber plant and far-end optics.
Selection Guide
1. Match it to a 2 km LC duplex SMF path
Select QDD-400G-FR4-S when the project needs Cisco 400G QSFP-DD optics over duplex G.652 single-mode fiber and the measured optical path fits the 2 km FR4 specification.
2. Check LR4 only when the FR4 budget is short
If the same link requires more distance or more optical loss margin, compare QDD-400G-LR4-S before the order is released. Do not use LR4 simply because the part number looks close; it changes the commercial line item and the optical budget.
3. Keep native 400GE separate from breakout optics
QDD-400G-FR4-S is for a native 400GE FR4 link. Use QDD-4X100G-FR-S or QDD-400G-DR4-S only when the Cisco platform, port mode, and remote devices require the documented breakout behavior.
4. Confirm the Cisco host before quote release
Cisco lists QSFP-DD module support through its transceiver compatibility resources, and one Nexus 3000 release note identifies support on the Nexus 3408 family from NX-OS 9.3(8). Validate the exact switch, router, line card, port, and release before reserving stock.
Ordering Checklist
|
Check Item |
What to Confirm |
Why It Matters |
|---|---|---|
|
Exact Product ID |
QDD-400G-FR4-S |
Prevents substitution with LR4, DR4, 4x100G FR, or SR4.2 optics |
|
Host compatibility |
Cisco platform, line card, QSFP-DD port, and software release |
Confirms the optic is supported in the intended device |
|
Fiber plant |
Duplex G.652 single-mode fiber with LC PC or UPC patch cords |
FR4 is not an MPO parallel-fiber optic |
|
Optical reach |
Up to 2 km |
Keeps the route inside Cisco’s documented FR4 distance |
|
Link budget |
4 dB maximum supported insertion loss |
Helps catch patch-panel or cross-connect loss before deployment |
|
Remote 400G optic |
Matching 400G FR4-compatible endpoint |
Avoids wavelength, reach, or connector mismatch |
Specifications
| Parameter | Specification | Parameter | Specification |
|---|---|---|---|
| Product ID | QDD-400G-FR4-S | Product type | 400GBASE-FR4 QSFP-DD optical transceiver |
| Form factor | QSFP-DD | Ordering description | 400G QSFP-DD Transceiver, 400GBASE-FR4, Duplex LC, 2km Duplex SMF |
| Supported Ethernet rate | 400 Gigabit Ethernet | Connector type | Duplex LC PC/UPC |
| Fiber type | Single-mode fiber | Fiber standard | G.652 |
| Cable topology | Duplex SMF | Maximum reach | 2 km |
| Pull tab color | Green | Nominal data rate | 425 Gbps |
| High-speed electrical interface | 400GAUI-8/CEI-56G-VSR-PAM4 | Wavelengths | 1270, 1290, 1310, and 1330 nm |
| Signal structure | Four CWDM grid optical wavelengths | Average transmit power per lane | -3.2 to +3.5 dBm |
| Average receive power per lane | -7.3 to +3.5 dBm | Maximum supported insertion loss | 4 dB |
| Pre-FEC bit error ratio | 2.4 x 10^-4 | FEC location | Host platform |
| Maximum power consumption | 12 W | Module dimensions with pull tab | 8.5 x 18.4 x 78.3/93.3 mm |
| Maximum module weight | 100 g | Module operating temperature | 0 to 75 degrees C |
| Storage temperature | -40 to 85 degrees C | Laser class | Class 1 |
| Compliance reference | RoHS 6 | Standard warranty | 5 years |
Get More Information
Need pricing, stock, or shipping details for the QDD-400G-FR4-S ? Layer23-Switch can help you check current availability, lead time, and delivery options for this. Send us the part number, quantity, and destination country via live chat or email sales@layer23-switch.com for a fast quotation.
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