QDD-400G-LR4-S – 400G LR4 QSFP-DD – Duplex LC SMF – 10km Reach
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QDD-400G-LR4-S Description
QDD-400G-LR4-S is a Cisco 400G QSFP-DD LR4 optical transceiver for native 400GE links over duplex single-mode fiber, used when a QSFP-DD host port needs a long-reach LC fiber connection for a 400G data center or routed optical-link BOM. Cisco official documentation identifies this SKU as a 400GBASE-LR4 module with duplex LC connectors, up to 10 km reach over SMF, four CWDM-grid optical wavelengths at 1270, 1290, 1310, and 1330 nm, 400GAUI-8/CEI-56G-VSR-PAM4 electrical interface support, and host-platform FEC.
Quick Specs
|
Parameter |
Specification |
|---|---|
|
Product ID |
QDD-400G-LR4-S |
|
Product type |
400G-LR4 QSFP-DD optical transceiver |
|
Form factor |
QSFP-DD |
|
Ethernet rate |
400 Gigabit Ethernet |
|
Connector type |
Duplex LC PC/UPC |
|
Fiber type |
Single-mode fiber |
|
Fiber standard |
G.652 |
|
Maximum reach |
10 km |
|
Nominal wavelengths |
1270, 1290, 1310, and 1330 nm |
|
High-speed electrical interface |
400GAUI-8/CEI-56G-VSR-PAM4 |
|
Maximum supported insertion loss |
6.3 dB |
|
Maximum power consumption |
12 W |
|
Module operating temperature |
0 to 75 degrees C |
Application Scenarios
Use QDD-400G-LR4-S when the planned 400G path uses duplex single-mode fiber and the optical distance is within Cisco’s documented 10 km reach. This is the LC duplex LR4 choice, not an MPO parallel fiber module.
This transceiver is useful when a Cisco QSFP-DD port needs a longer SMF link than QDD-400G-FR4-S can cover. Confirm the host device and software support before the order moves from price check to purchase approval.
Keep QDD-400G-LR4-S separate from DR4, 4x100G LR, FR4, BiDi, and SR optics in spare pools. The part numbers look similar in procurement systems, but the connector type, fiber plant, and operating mode are not interchangeable.
Product Comparison
|
Parameter |
QDD-400G-LR4-S |
QDD-4X100G-LR-S | ||
|---|---|---|---|---|
|
Product type |
400G-LR4 QSFP-DD transceiver |
400G-FR4 QSFP-DD transceiver |
4 x 100GBASE-LR1 QSFP-DD transceiver |
400GBASE-DR4 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 |
10 km |
2 km |
10 km |
500 m |
|
Breakout capability |
Native 400GE LR4 link |
Native 400GE FR4 link |
4 x 100GBASE-LR1 operation |
4 x 100G breakout to DR, FR, or LR peer optics |
|
Nominal wavelength |
1270, 1290, 1310, and 1330 nm |
1270, 1290, 1310, and 1330 nm |
1310 nm |
1310 nm |
|
Nominal data rate |
425 Gbps |
425 Gbps |
4 x 100GE |
425 Gbps |
|
Maximum supported insertion loss |
6.3 dB |
4 dB |
6.3 dB |
3 dB |
|
Maximum power consumption |
12 W |
12 W |
12 W |
12 W |
- QDD-400G-LR4-S is the duplex LC single-mode option when the 400G path requires Cisco’s documented 10 km LR4 reach.
- QDD-400G-FR4-S uses the same LC duplex cabling style but is the shorter 2 km FR4 choice, so the link budget should be checked before substitution.
- QDD-4X100G-LR-S and QDD-400G-DR4-S use MPO-12 parallel SMF and belong in a different breakout or parallel-fiber design.
- QDD-400G-SR4.2-BD is a multimode MPO option and should not replace an LR4 SMF line item without changing the fiber plant and far-end optics.
Selection Guide
1. Choose it for 10 km duplex SMF 400GE
Select QDD-400G-LR4-S when the BOM needs a Cisco QSFP-DD 400G transceiver over duplex single-mode fiber and the planned optical path stays within the 10 km LR4 reach.
2. Check FR4 before overbuying reach
If the same LC duplex SMF run is within 2 km, QDD-400G-FR4-S may match the physical requirement. Use LR4 when the extra reach and 6.3 dB insertion-loss budget are required.
3. Avoid mixing LR4 with breakout optics
Do not treat QDD-400G-LR4-S as a substitute for QDD-4X100G-LR-S or QDD-400G-DR4-S. Those parts use MPO-12 parallel SMF and different operating modes.
4. Confirm the host platform before release
Check the exact Cisco switch, router, line card, QSFP-DD port, and software release in Cisco compatibility documentation before requesting a final quote or reserving stock.
Ordering Checklist
|
Check Item |
What to Confirm |
Why It Matters |
|---|---|---|
|
Exact Product ID |
QDD-400G-LR4-S |
Prevents substitution with FR4, DR4, 4x100G LR, SR, or LR8 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 single-mode fiber using LC PC or UPC patch cords |
LR4 is not an MPO parallel-fiber optic |
|
Optical reach |
Up to 10 km over G.652 SMF |
Keeps the planned path inside Cisco’s documented distance |
|
Link budget |
6.3 dB maximum supported insertion loss |
Helps avoid approval of an SMF path that is too lossy |
|
Remote 400G optic |
Matching 400G LR4-compatible endpoint |
Avoids a wavelength, reach, or connector mismatch |
Specifications
| Parameter | Specification | Parameter | Specification |
|---|---|---|---|
| Product ID | QDD-400G-LR4-S | Product type | 400G-LR4 QSFP-DD optical transceiver |
| Form factor | QSFP-DD | Ordering description | 400G QSFP-DD Transceiver, 400G-LR4, Duplex LC, 10km 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 | 10 km |
| Pull tab color | Blue | 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 | -2.7 to +5.1 dBm |
| Average receive power per lane | -9.0 to +5.1 dBm | Maximum supported insertion loss | 6.3 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-LR4-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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