The Arista QDD-400G-ER4 is a QSFP-DD 400GBASE-ER4-30 module from Arista Networks for 400 Gbps links. It plugs into a QSFP-DD port on an Arista switch and is used for 400G spine and super-spine fabrics, AI/ML clusters, 4 × 100G breakout and data-centre interconnect.

Arista specifies the QDD-400G-ER4 for 30 km on duplex single-mode fiber. Arista notes that proper optical attenuation is required on shorter links to protect the receiver from damage.

Per Arista's published optics data sheet, the QDD-400G-ER4 transmits 0 to 5.4 dBm/lane and receives −14.7 to −3.4 dBm/lane.

The QDD-400G-ER4 uses a Duplex LC connector on duplex single-mode (G.652), at 1304–1310 nm (4-lambda). Both ends of the link must use the same optical standard.

It works in Arista switches with QSFP-DD ports that support this optic. Send us your switch model and EOS version and we will check it against Arista's Transceiver and Cable Guide before dispatch, so you only receive a module that works in your port.

It depends only on your switch port. OSFP ports need OSFP optics and QSFP-DD ports need QSFP-DD optics; they are not mechanically interchangeable. If both ends run the same optical standard (e.g. DR4 to DR4), an OSFP module and a QSFP-DD module interoperate over the fibre.

Yes. Next Gen Networks supplies original Arista Networks optics, not third-party lookalikes or grey-market stock. Every unit is checked before dispatch, and we share the serial numbers on request so you can verify them in EOS ('show inventory').

The Arista QDD-400G-ER4 price in India depends on quantity, delivery city and current stock. Next Gen Networks supplies it with a GST invoice (input tax credit ready) and pan-India dispatch from New Delhi. Send the part number, quantity and delivery city on WhatsApp +91-7827955775 or email Sales@nextgennetworks.in and we reply with a GST quote.