PIID → Colo Rack Mapping

How Physical Infrastructure IDs (PIIDs) get assigned to colo rack positions — and how TSmartLabel cross-references Excel fiber assignments against DFSA scope documents to catch gaps.

A PIID (Physical Infrastructure ID) is a circuit identifier assigned to each fiber pair in a hyperscaler dark fiber build. In practice, a PIID like BHBZ8383 tracks a specific fiber pair from its source OSX port all the way to the colo rack where the customer terminates it.

The Mapping Challenge

Your fiber assignment Excel tells you which PIID lives at which OSX port. Your DFSA Scope document tells you which PIID should extend to which rack. Your SOW might reference yet another list. If these three lists don’t agree, you’ll have fibers that reach the wrong rack — or no rack at all.

This is one of the most common (and costly) errors in dark fiber deployments. A technician installs 16 fibers, discovers 3 PIIDs were assigned to the wrong rack position, and now faces a re-pull on a live site.

The Source Documents

Fiber Assignment XLSX — Contains the physical path: which CLLI, which OSX, which tray/port. Rows are organized by span (DNVTCO56_HDSNCOAJ), fiber number, and PIID/Circuit ID.

DFSA Scope DOCX — Contains the intent: which PIIDs should EXTEND (carry through to a colo rack) vs. LEAVE_AT_OSX (terminate at the cross-connect), and for EXTEND PIIDs, which rack code.

SOW DOCX — Often has a third copy of the PIID list, sometimes with slightly different ranges.

A Concrete Example

From a real N1003160 build (Anthropic, DNVTCO56–SLKDUTYI route):

The fiber assignment Excel has 240 rows across 15 spans. The DFSA scope table has 3 rack assignment blocks. TSmartLabel’s cross-check engine compares these set by set:

1. Extract PIID set from Excel — every Circuit ID column value across all 15 sheets.
2. Extract PIID set from DFSA — every PIID listed under rack assignment tables.
3. Diff the sets — any PIID in Excel but not in DFSA, or in DFSA but not in Excel, becomes a MappingConflict with severity: HIGH.

Rack Code Format

Rack codes like 302.03 follow a consistent format: <row>.<position>. Row 302, position 03. In practice, rack positions are sequential within a row, so 302.03 through 302.08 is a contiguous 6-rack block.

Labels destined for a colo rack include the rack code in the {rack} variable slot. Customer templates vary:

• Meta: rack code on line 3 of the label
• Google: rack code encoded in the QR payload, not printed directly
• Anthropic: rack code after the site pair on the last line

What TSmartLabel Does

After you upload and approve documents for a Netbuild, the conflict engine runs automatically:

1. Extracts PIID sets from all approved documents
2. Builds the EXTEND/LEAVE_AT_OSX assignment map
3. Cross-checks fiber numbers against PIID assignments (a fiber can’t have two PIIDs)
4. Flags missing rack codes for any EXTEND PIID
5. Marks the Netbuild’s conflict severity as HIGH if any gaps exist

No label job can be started for a span with unresolved HIGH severity conflicts — unless an ADMIN explicitly overrides with a reason that gets written to the audit log.