OSFP224 (OSFP 224G)

OSFP224 is the OSFP form factor taken to 200G per electrical lane: the same eight-lane, integrated-heat-sink module as 400G/800G OSFP, but with a connector, cage and host channel qualified for 224G signalling (212.5 GBd PAM4 including FEC overhead). Eight such lanes make 1.6 Tb/s in one OSFP port without changing the faceplate density. It is one of the two industry paths to 1.6T pluggables; the other is OSFP-XD, which keeps 100G lanes and doubles their number. The base form factor is described in OSFP.

Key facts

What changed against 800G OSFP

The absence of a gearbox in the DR8 case matters: the module DSP retimes eight lanes 1:1 instead of multiplexing, which saves power and makes linear (LPO) or half-retimed 1.6T optics more plausible (Modulation & DSP).

Variants

• OSFP224 finned — integrated heat sink for switch faceplates with open airflow.
• OSFP-RHS ("riding heat sink") — flat-top module for NICs and cages with a host-side heat sink; electrically identical.
• Twin-port modules (2 × 800G) — two independent 4-lane ports behind one module, each with its own MPO or LC pair; used for InfiniBand XDR and 800G Ethernet breakout from a 1.6T cage (IB cabling).
• DAC / AEC — passive copper reach at 200G/lane is under about 1 m; AEC with retimers extends to 2–3 m (Cable internals).

Specifications

• OSFP MSA specification, 224G-capable revisions — mechanical, electrical (224G channel), thermal and management references; maintained by the OSFP MSA.
• IEEE 802.3dj — 200G/lane electrical and optical PMDs (1.6TBASE-DR8, 800GBASE-DR4 at 200G/λ) (Ethernet generations).
• OIF CEI-224G — the electrical channel definitions the connector is qualified against.
• Management: CMIS; codes from SFF-8024.

Management interface

Identical to any OSFP: lower page, banked lane pages (all eight lanes in bank 0), module and data-path state machines, VDM and CDB. The 200G lane rate is not a new identifier — byte 0 stays 19h — but appears in the host interface IDs of the application descriptors and in the media interface IDs for 200G/λ PMDs (CMIS lower page map). Power class declarations (page 00h byte 200, MaxPower 201) are where a 1.6T module differs from an 800G one on paper.

Compatibility notes

• An OSFP224 port accepts 800G and 400G OSFP modules; a 1.6T module needs a host with 200G/lane SerDes — in an 800G-era OSFP port it will not link at 1.6T, and may not be supported at all.
• Not interchangeable with QSFP-DD800 / QSFP-DD1600 mechanically, the same way OSFP and QSFP-DD never were (Form factors).
• 224G signalling shortens passive copper reach and tightens connector cleanliness and seating requirements; per-lane pre-FEC BER is the health metric (VDM & FEC metrics).
• Thermal: 1.6T DSP modules run at the top of the OSFP power envelope; airflow and the correct finned/flat variant matter more than ever (Power & thermal).

In CodingBox

CodingBox reads OSFP224 modules with the CMIS decoder: identity, power class, application descriptors with their 200G-lane host and media interface IDs, module and data-path states and per-lane DDM for eight lanes on Check transceiver, EEPROM editor and DDM. Reading such a module requires a cradle rated for its power class (Programmers).