Limitations & Network Requirements
This page covers important technical limitations and network requirements you should be aware of when deploying Missing Features ACAP.
Live Video Streaming
Several features use live video streaming via WebCodecs over WebSocket:
- Dashboard: AXIS Live Stream widget
- Scene Analysis Triggers: Live preview with overlays
- Spot Color Detector: Video feed for color detection regions
- Flow: AXIS Live Stream node
How It Works
Video streaming uses WebCodecs for H.264 decoding over a WebSocket connection:
- Browser connects to the device via WebSocket (TCP)
- Device sends H.264 video frames over the WebSocket
- Browser decodes frames using WebCodecs API
Network Requirements
| Requirement | Details |
|---|---|
| Protocol | TCP (WebSocket over HTTPS) |
| Ports | Same port as web UI (Axis HTTP/HTTPS, typically 443) |
| Direction | Standard HTTP/WebSocket, routed through the Axis reverse proxy |
Advantages Over Previous WebRTC Approach
| Aspect | WebCodecs (Current) | WebRTC (Previous) |
|---|---|---|
| NAT Traversal | Not needed - uses TCP | Required STUN/TURN |
| Firewall | Only the Axis web port needed | Required UDP ports |
| Remote Access | Works if UI works | Often failed remotely |
| Setup | No configuration | Needed relay servers |
Troubleshooting Video Streams
| Issue | Possible Cause | Solution |
|---|---|---|
| Video not loading | WebSocket blocked | Verify the Axis web interface is reachable from the client |
| Decoder error | Browser compatibility | Use Chrome, Firefox, or Edge |
| Stream freezes | Network interruption | Check network stability |
| No video, no error | Device not streaming | Verify device is accessible |
Browser Requirements
For best compatibility with video streaming features (WebCodecs API):
| Browser | Support |
|---|---|
| Chrome 94+ | Fully supported |
| Firefox 130+ | Fully supported |
| Edge 94+ | Fully supported |
| Safari 16.4+ | Supported |
Tip
WebCodecs is a modern browser API for hardware-accelerated video decoding. If video streaming doesn't work, ensure your browser is up to date.
SD Card Requirements
Several features require an SD card to be inserted and formatted:
- Storage Nodes: All SD Card file operations
- Image to SD-Card: Saving captured images
- Database (SQLite): Local database storage
Image Cache Limits
The in-memory image cache has the following constraints:
| Constraint | Value |
|---|---|
| Maximum cached images | 10 |
| Maximum cache size | 30 MB |
| Eviction policy | Oldest images removed first |
When the cache is full, the oldest images are automatically evicted to make room for new ones.
Database Constraints
Connection Settings
| Setting | Default Value |
|---|---|
| Connection timeout | 10 seconds |
| Max retry attempts | 3 |
| Retry delay | 1 second |
| Slow query threshold | 5 seconds |
Supported databases
SQLite, MySQL, PostgreSQL, SQL Server
Note
External databases (MySQL, PostgreSQL, SQL Server) require network access from the Axis device to the database server.
Network Timeouts
Protocol-Specific Timeouts
| Protocol | Timeout/Interval |
|---|---|
| TCP Sender dial | 2 seconds |
| HTTP Request | Configurable (default varies) |
| Webhook Request | 30 seconds |
| Modbus TCP heartbeat | 2 seconds |
| OPC UA heartbeat | 5 seconds |
| OPC UA client close | 2 seconds |
| RTMP dial | 5 seconds |
| RTMP read/write | 2 seconds |
Default Ports
| Protocol | Default Port |
|---|---|
| Modbus TCP | 502 |
| Valid port range | 1 - 65535 |
Spot Color Detector
| Setting | Value |
|---|---|
| Maximum sample points | 8000 |
| Default analysis interval | 500 ms |
| Default framerate | 5 FPS |
| Default hysteresis threshold | 30.0 |
File Download Limits
When downloading files via the SD Card Explorer:
| File Type | Maximum Size |
|---|---|
| Text files | 25 MB |
| Binary files | 50 MB |
Summary
| Feature | Requires |
|---|---|
| Web UI Access | Standard Axis HTTP/HTTPS port (typically 443) |
| Live Video Streaming | Standard Axis HTTP/HTTPS port (same as UI) |
| Remote Access | Reachability to the Axis web interface (direct or VPN) |
| SD Card Features | Inserted and formatted SD card |
| External Databases | Network access to database server |
| Modbus TCP | Port 502 (default) accessible |