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Device Fiber Overview

NetBox FMS injects a Fiber Overview tab on device detail pages (via template_content.py), giving operators a unified view of all fiber infrastructure connected to a device. This eliminates the need to navigate between multiple pages to assess a device's fiber connectivity, splice status, and closure configuration.

What the Tab Shows

The Fiber Overview tab consolidates the following information for the selected device:

  • Connected fiber cables -- the cables that form the device's fiber topology: those terminating on a rear port of the device, plus any cable that already carries a FiberCable. Each row shows cable type, strand link counts, and gland assignment. Splice jumpers -- the front-port-to-front-port cables created when a splice plan is applied -- are not listed here; they belong to the splice editor view.
  • Fiber strand status -- a per-strand breakdown showing whether each strand is available, in use, or spliced.
  • Associated splice plans -- one or more SplicePlan entries that reference strands terminating at the device. A single closure may have multiple active plans from different teams or projects.
  • Closure cable entry (gland) assignments -- for closure-type devices, the mapping of cables to physical entry points on the enclosure.

Add Cable

The Add Cable button in the summary card header opens a three-step wizard that creates a fiber cable from this closure to a far-end device: scope (far end, FiberCableType, port type), cable details (type, status, label, color, length, tenant, description), then a review step showing how many rear and front ports will be created on each device. See Fiber Cables.

ClosureCableEntry Management

Each ClosureCableEntry links a FiberCable to a specific entrance or gland label on a closure device. This tracks which cables enter through which physical openings on the closure, an essential detail for field technicians performing maintenance or troubleshooting.

Key capabilities:

  • Gland label assignment -- assign a descriptive label (e.g., "Port A", "Entry 3") to each cable entry point.
  • Inline editing -- gland assignments can be edited inline via HTMX-powered modals, allowing changes without leaving the device view.
  • Cable-to-entry mapping -- provides a clear record of cable routing into the closure for documentation and audit purposes.

From the Fiber Overview tab, operators can link cable topology for cables that are part of the device's fiber topology (see above); cables outside it, such as splice jumpers, are rejected. This triggers the link_cable_topology() workflow, which:

  1. Creates a FiberCable from an existing dcim.Cable.
  2. Proposes FrontPort adoption or creation based on the cable type's strand configuration.
  3. Confirms port mappings before committing changes.

This workflow bridges the gap between NetBox's native cable plant and the FMS fiber layer. See Fiber Cables for a detailed description of the topology linking process.

Tray Assignments

For closures with splice trays (modules whose type carries a TrayProfile), the Fiber Overview tab shows a tray assignments card listing each tray, its capacity, and the buffer tubes assigned to it. From this card an operator can:

  • Assign -- place an unassigned buffer tube onto a specific splice tray. Only trays with the Splice Tray role are offered.
  • Unassign -- remove a tube's tray assignment.
  • Auto-assign -- distribute all unassigned tubes across the closure's splice trays. Tubes at the same position across cables (e.g., T1 from Cable A and T1 from Cable B) are paired onto the same tray when its remaining max_fibers capacity allows.

Tubes can only be assigned once their fiber cable has a ClosureCableEntry on the closure. See Splice Planning: Preparing a Closure for the full setup sequence.

Assigning a tube to a tray moves the tube's closure-side strand front ports onto the tray module; removing the assignment returns them to the device. Note that the Assign and Auto-assign actions on this card move conflicting ports without prompting; the confirmation gate applies to the standard Tube Assignment form and the REST API.

Splice Editor Widget

An embedded splice editor is available directly from the device view, enabling quick creation and editing of splice plan entries without navigating away. This is particularly useful when:

  • Performing initial splice documentation for a newly installed closure.
  • Updating splice records during field maintenance.
  • Reviewing and correcting splice assignments reported by technicians.

The widget provides the same functionality as the full splice plan interface in a compact, context-aware form. See Splice Planning for the full workflow and splice plan management details.

Which Plan the Editor Opens

A closure can carry several splice plans at once, so the tab picks one deterministically:

  1. Draft plans first, oldest one first -- drafts are the only plans that accept edits.
  2. If no draft exists, the most relevant non-draft plan is loaded instead, in the order pending approval, approved, archived.

Two controls override or explain that choice:

  • Plan selector -- when the closure has more than one draft plan, the tab renders a row of buttons above the canvas. Each button reloads the editor with ?plan=<id> for that plan; the same query parameter can be used directly in a link or bookmark. A plan id that belongs to a different closure returns a 404.
  • Read-only banner -- when only non-draft plans exist, the editor loads read only and shows a warning naming the loaded plan and its status, with a shortcut for creating a new draft plan for the closure.

Pending Work Tab

Closure devices with approved splice plans display a Pending Work tab on their detail page. This tab provides a combined view of all approved plans targeting the closure, enabling batch application of changes.

What the Tab Shows

  • Per-plan summary -- Each approved plan is listed with its name, project, and a summary of the changes it introduces (additions, removals, unchanged splices).
  • Combined diff -- The aggregate diff across all approved plans, organized by tray. Each tray section shows which splices will be added, removed, or kept.
  • Apply All action -- A single button applies all approved plans' changes atomically. This creates and removes splice cables as needed, then archives the applied plans.

Batch Apply Workflow

Instead of applying plans individually, the Pending Work tab merges all approved plans into a single operation:

  1. Multiple teams create splice plans for the same closure (each plan is independent).
  2. Plans go through the approval workflow (draft -> pending_approval -> approved).
  3. A field technician opens the closure's Pending Work tab and reviews the combined diff.
  4. The "Apply All" action commits all changes in a single atomic transaction.
  5. Applied plans are automatically archived.

This approach ensures that a closure is only opened once for all pending changes, reducing field visits and minimizing the risk of partial updates.