Form factors & standards

An optical transceiver's form factor defines its physical size, electrical interface and how many channels it carries. The memory layout that CodingBox reads is defined by industry standards tied to those form factors.

Common form factors

Memory standards

The management interface — the registers a host or programmer reads — is described by these specifications:

• SFF-8472 — diagnostics and management for SFP/SFP+ modules.
• SFF-8636 — management for QSFP+/QSFP28 modules.
• CMIS — the Common Management Interface Specification, used by QSFP-DD and newer

pluggables. It organises memory into a lower page plus banked upper pages.

Why it matters

The form factor tells CodingBox which standard to apply, so the identity and DDM fields are decoded from the right memory addresses. Reading an SFP as if it were a QSFP would misinterpret every field.

CodingBox detects the form factor automatically and selects the matching decoder.