Features Segment Utilization

Cable Segment Utilization

The Cable Segment Utilization feature monitors the shared DOCSIS cable segment load on FRITZ!Box cable modems. It shows both the total segment utilization (across all customers on your cable segment) and your own device's share, in both downstream and upstream directions.

Availability: FRITZ!Box cable modems only. The feature is automatically enabled when a FRITZ!Box is configured.

Why This Matters

Cable internet is a shared medium -- you share bandwidth with your neighbors on the same cable segment. When the segment is heavily loaded during peak hours (typically evenings), everyone's speeds suffer. This feature lets you:

• See peak-hour congestion -- Identify when your segment is overloaded
• Correlate slowdowns -- Compare segment load with your signal quality and speedtest results
• Build evidence -- Document systematic oversubscription for ISP complaints

What You See

KPI Cards

Three cards at the top show the current state:

Card	Description
Downstream Total	Network-wide downstream utilization (%) with min/avg/max stats
Upstream Total	Network-wide upstream utilization (%) with min/avg/max stats
Status	Polling state and sample count

Time-Series Charts

Two charts show utilization over time:

• Downstream Utilization -- Total segment load (solid purple) vs. your own share (dashed indigo)
• Upstream Utilization -- Total segment load (solid purple) vs. your own share (dashed indigo)

Time Ranges

Range	Description
24h	Last 24 hours with full detail
7d	Last 7 days
30d	Last 30 days
All	Complete history

Correlation Integration

Segment utilization data is included in the Correlation Analysis timeline. This lets you overlay segment load alongside signal metrics, speedtest results, and events to identify patterns.

Data Collection

• Source: FRITZ!Box monitoring API (/api/v0/monitor/segment/0)
• Poll interval: Every 5 minutes
• Authentication: Uses your existing FRITZ!Box credentials
• Backfill: Missed samples are retroactively collected from modem history

Data Retention

Age	Granularity
0-7 days	Raw 5-minute samples
7-30 days	5-minute averages
30-365 days	15-minute averages
>365 days	Automatically deleted

Accuracy Note

Values are estimates provided by the FRITZ!Box. They reflect the modem's view of segment load, which may differ from actual CMTS-level measurements.

API Endpoints

Method	Path	Description
GET	/api/fritzbox/segment-utilization?range=24h	Samples, latest value, and statistics
GET	/api/fritzbox/segment-utilization/range?start=<ISO>&end=<ISO>	Range query for correlation

See API Reference for full details.

Related

• Dashboard
• Correlation Analysis
• FRITZ!Box Modem Page