OEM part numbers: how vendors name optics

A switch matches a module against its supported list by the part number and vendor name stored in the module's EEPROM, so the exact string matters — down to a suffix letter. Each vendor has a naming grammar, and knowing it lets you read a PN off a label or a show output and know the rate, reach, wavelength and grade without a datasheet. This page collects the grammars of the common brands and the rules for matching them.

Where the PN lives

Formatting rules and what else hosts compare: Vendor fields.

Naming grammars

Conventions shift between product generations; the grammar tells you how to read a PN, not that every PN exists.

Grades and suffixes worth knowing

Matching rules on the switch

• Most platforms compare vendor name + PN against a table; some compare the PN prefix only; a few also verify a vendor-specific signature (How each NOS validates a module).
• Case, trailing spaces and padding must match the specification (space-padded ASCII); a NUL-padded PN fails silently (Vendor fields).
• The type string the switch prints is often built from the PN, not from compliance codes — a PN that says -LR on an SR module will be displayed as LR and then fail to link (Compliance codes).
• Serial-number formats and date codes are rarely checked but are inspected by TAC.

Finding the right PN for a port

1. Platform's supported-optics list (or transceiver compatibility tool) → PN for the PMD you need (Compatibility matrices).
2. Confirm the PMD behind the PN (rate, reach, wavelength, connector) against the plant.
3. Check the grade suffix against temperature and reach requirements.
4. On the bench, compare the module's EEPROM PN and vendor name with the list entry character by character (Check transceiver).

In CodingBox

The code database stores complete identities under the vendor PN so a module can be coded to an entry in one step; the EEPROM editor enforces the 16-character, space-padded format and recalculates checksums. Coding a PN that does not describe the real optics moves the failure from the whitelist to the link (EEPROM recoding).

The rest of the label around the part number — serial and date formats, wavelength and reach fields, latch colours, safety marks: Labels & colour codes.