Telemetry Data Model

Different vendors describe the same measurement in different ways — one switch reports CPU load one way, another reports it slightly differently, and a third vendor’s gear calls it something else entirely. The Telemetry Data Model (TDM) is GridNMS’s canonical, vendor-neutral vocabulary for that data: a fixed set of named fields that every supported device’s readings are normalized onto. Write a detection or a threshold against a TDM field once, and it fires on every vendor whose data maps to it — not just the one you tested it on.

Note

This is a different model from the Log Data Model, which classifies log messages. This page covers device telemetry — the metric and inventory readings collected from your gear.

Where to find it

Open Configure → Logs and Events and select the Telemetry Data Model tab. It’s a read-only reference — there’s nothing to configure here, just the field vocabulary and how well each one is covered in your environment.

The fields are split into two tables:

• Metric fields — numeric, point-in-time readings (CPU utilization, temperature, interface counters, and so on).
• State / inventory fields — descriptive facts about a device rather than a measurement (a model number, a firmware version, an operational state).

Reading the table

Column	What it tells you
Field	The canonical field name — what a rule or threshold references.
Component	Which part of the device the field describes (for example, a specific sensor or interface).
Unit	The unit the value is expressed in, where applicable.
Registered	Whether this field is part of GridNMS’s known vocabulary in your environment: Registered (recognized and active), Disabled (recognized but turned off), or Unregistered (not yet part of the vocabulary).
Sources	Which vendor modules feed this field. A solid badge is a direct reading; an outlined badge marks a value that’s composed — derived by combining more than one underlying reading rather than read directly.

If GridNMS can’t reach its update feed, a banner notes that delivery/version status is unavailable — the field reference itself doesn’t depend on that connection and is always available.

Where to go next

• See how logs are classified with a comparable model in The Log Data Model.
• Put these fields to work in Monitoring & Metrics and Detections.
• Reference the full rule syntax in Writing Rules.