OTDR .sor File Naming Rules
How hyperscaler customers specify OTDR test file naming, why it matters for as-built documentation, and how TSmartLabel validates filenames against scope requirements.
OTDR (Optical Time-Domain Reflectometer) testing generates .sor (Standard OTDR Record) files — one per fiber, per direction, per wavelength. On a 240-fiber, 4-wavelength build with bidirectional shots, that’s 1,920 files. Without a consistent naming convention, tracing a specific test result back to a specific fiber becomes a documentation nightmare.
Why Naming Matters
At project closeout, the customer’s as-built package requires:
- Test results that can be matched to the fiber assignment Excel by fiber number and PIID
- Clear indication of shot direction (A→B vs. B→A) and wavelength
- File organization that maps to span structure
If your naming convention doesn’t match the customer’s spec, the as-built package gets rejected and you’re re-running tests or at minimum re-organizing files. Either way, it’s days of delay at closeout.
Standard Naming Convention
A typical spec-compliant filename looks like:
N1003160_HDSNCOAJ-AULTCOAT_F05_1310nm_A-B.sor
Breaking it down:
| Segment | Value | Rule |
|---|---|---|
| Netbuild | N1003160 | Exact netbuild code, no spaces |
| Span | HDSNCOAJ-AULTCOAT | {siteA}-{siteB}, always A then B regardless of shot direction |
| Fiber | F05 | Zero-padded to 2 digits (F01–F16 for a 16-fiber build) |
| Wavelength | 1310nm | 1310nm, 1550nm, 1625nm, or 1650nm |
| Direction | A-B | A-B for the A→B direction shot, B-A for the reverse |
Customer Variations
Meta spec: Requires all four wavelengths (1310, 1550, 1625, 1650nm) with round-trip shots (A→B and B→A). File naming uses _ separators throughout, and the span is always listed as the longer segment first.
Google spec: Requires 1310nm and 1550nm only. One-way shots are acceptable on spans shorter than 10km. Uses - between CLLI codes but _ elsewhere.
Microsoft spec: Requires 1310nm and 1625nm. Fiber number zero-padding to 3 digits (F005). Adds a PASS/FAIL suffix: ..._A-B_PASS.sor.
Anthropic spec: 1310nm and 1550nm round-trip. Includes the PIID in the filename: N1003160_BHBZ8383_HDSNCOAJ-AULTCOAT_F05_1310nm_A-B.sor.
TSmartLabel’s OTDR Validation
TSmartLabel’s OTDR module (coming in a future release) will:
- Ingest a file listing from your test equipment export
- Parse each filename against the customer’s spec
- Flag missing files — if span HDSNCOAJ-AULTCOAT requires 32 files (16 fibers × 2 directions × 1310/1550) and only 30 are present, it reports exactly which fiber/direction/wavelength is missing
- Flag naming violations — wrong separator, wrong zero-padding, missing wavelength token
- Cross-reference against fiber assignment — verify that every fiber number in the test files corresponds to a real fiber in the workbook
Manual Validation Today
Until TSmartLabel’s OTDR module ships, the fastest manual check is to sort your .sor file directory and verify:
- File count = (number of fibers) × (number of wavelengths) × 2 (for round-trip)
- All zero-padded fiber numbers are present with no gaps
- Each file has both an
A-BandB-Acounterpart
For a 16-fiber, 4-wavelength Anthropic build: 16 × 4 × 2 = 128 files per span. Across 15 spans: 1,920 files total.
The Scope Document
Testing specifications live in the DFSA Scope .docx file, typically in a section titled “Testing Requirements” or “Acceptance Criteria.” TSmartLabel’s document extractor pulls wavelengths, shot types, and file naming rules from this section and stores them under testing_specs in the Netbuild record — so you can reference the requirements without hunting through the Word document.