Arista Compatible 400G QSFP-DD Optical Transceivers
Product Overview
The Apex 400G QSFP-DD range on this page is built for Arista leaf, spine and campus switches whose firmware asks for Arista coded optics. These are third party modules to the QSFP-DD MSA, not products of Arista and not affiliated with Arista.
The economics are straightforward. A live port has to keep working for years, while the price of a factory module and the lead time for a new one can turn one failed optic into an expensive event. A coded module of the same grade brings the port back up at a fraction of the cost, which is why operators keep a small coded spare stock beside the live spares.
The part that decides whether the link comes up is the EEPROM image, not the optics. Written for the named platform, it makes the host accept the module and report the expected values through DDM. Tell us the platform, the firmware version and the incumbent part number, and the coding is confirmed before the order is released.
Key Features
- 400G QSFP-DD range covering SR8, DR4, DR4+, FR4, FR8, LR4 grades
- EEPROM coded for the platform and the part number you name
- Third party product, not manufactured by or affiliated with Arista
- Same grade and reach class as the factory part at a lower cost per port
- Digital Diagnostic Monitoring (DDM) with live optical, temperature and voltage readings
- Tested for optical power and error rate, with a test report supplied
- Common grades held in stock for same-day quoting
- RoHS compliant, supplied with a three year warranty
Technical Specifications
| Specification | Detail |
|---|
| Part Number | APX-QSFP-DD-400G-xx (grade dependent) |
| Manufacturer | Apex |
| Product Type | Third party compatible module, QSFP-DD MSA |
| Platform Compatibility | Arista switches |
| Data Rate | 425Gbps (8 x 53.125Gbps PAM4) |
| Data Rate | 425Gbps (8 x 53.125Gbps PAM4) |
| Form Factor | QSFP-DD, hot pluggable |
| Coding | Written to order for the named platform |
| DDM / DOM | Supported |
| Supply Voltage | 3.3V |
| Compliance | QSFP-DD MSA, RoHS |
| Temperature | 0 to 70C commercial |
Ordering Options by Grade
The 400G QSFP-DD grades are listed below as plain text so they can be copied into an RFQ or a spreadsheet. Each grade is ordered with the coding for the platform you name.
| Grade | Wavelength | Media | Reach class | Interface |
|---|
| SR8 | 850nm | Multimode | 100m | MPO-16 |
| DR4 | 1310nm | Single mode | 500m | MPO-12 |
| DR4+ | 1310nm | Single mode | 2km | MPO-12 |
| FR4 | 1310nm | Single mode | 2km | LC duplex |
| FR8 | 1310nm | Single mode | 2km | LC duplex |
| LR4 | 1310nm | Single mode | 10km | LC duplex |
| LR8 | 1310nm | Single mode | 10km | LC duplex |
| 2x200G or 4x100G breakout | via DR4 or FR4 | Single mode | 500m to 2km | MPO-12 / LC duplex |
| ZR | Coherent, C-band | Single mode | 80km and beyond | LC duplex |
Applications
Spine and Super-Spine Links
400G links inside the fabric, where DR4 and FR4 cover the rack and row distances and LR4 and LR8 cover the campus span.
400G to 4x100G Breakout
One 400G port feeding four 100G server ports, which is how most operators keep the leaf tier at 100G while the spine moves up.
Metro and DCI
2km to 80km links on FR4, FR8, LR4 and coherent ZR grades, with the same coded family from the switch to the site boundary.
Compatibility and Coding
Coding is what makes a compatible module work in a Arista port. The module carries an EEPROM image written for the host, so the platform accepts it, reports its values through DDM and links at the expected rate and reach. Give us the platform and the part number you are replacing, and we confirm the coding, the grade and the compatibility before the order is released.
Apex supplies these modules as a third party source. The products are not manufactured by, endorsed by, or affiliated with Arista, and no Arista warranty or support applies to them. Where a platform enforces vendor locking beyond the EEPROM image, we say so before the order rather than after.
Upgrade and Interoperability Notes
Selection usually comes down to the fibre you already own. Multimode trays mean an SR class, single mode trays mean the duplex or parallel single mode classes, and the reach class should be the next one above the longest span in the plan.
Keep the coding consistent across the installed base and the spare shelf. Mixing codings inside one link is the most common cause of a port that reports green optics and still will not come up.
Tell us the platform, the firmware version and the incumbent part number and the coding is confirmed before the order is released. If the platform blocks third party modules, you hear it before the shipment, not after. Related reading: Data Center Leaf-Spine 400G Optics Selection Guide.
Related Products
Frequently Asked Questions
DR4, FR4 or LR4: how do I pick the 400G grade?
Reach and fibre decide it. DR4 is the 500m parallel single mode class on MPO-12, FR4 the 2km class on duplex LC, LR4 the 10km class. If the reach is between two classes, go to the higher one.
Do I need different modules for 2km and 10km on the same switch?
Yes, the grade is part of the module. The port accepts whichever grade is fitted, but the coding and the optical class have to match the link you are building.
How many fibres does a 400G link use?
DR4 and DR4+ use eight fibres over MPO-12, SR8 uses sixteen fibres over MPO-16, and FR4, FR8, LR4 and LR8 use a duplex LC pair. The connector count is worth checking before you order cabling.
Is a 400G port compatible with 200G and 100G modules?
Where the platform supports lower rates in the same port, the port is configured down and the module has to be coded for that speed. Send the configuration and we match the coding to it.
Why Choose Apex
- Optical supply from 1.25G to 1.6T, including compatible and coded ranges for the main switch platforms.
- Coding confirmed against the platform and the part number before the order is released.
- Every module tested for optical power and error rate, with a test report supplied.
- Backed by a three year warranty and technical support before and after the sale.
