Active calls

Active Calls

Real-time monitoring of ongoing VoIP calls with live listening capability (G.711 codec, sniffer v7+).

Overview

Feature	Details
Auto-refresh	Default: 2 seconds
Communication	TCP port 5029 (Manager API)
Live listening	G.711 codec only (requires sniffer version 7+)
Direct URL	admin.php?activecalls=1

ℹ️ Note: If calls are not displayed, verify that the web server can reach the sniffer's manager port 5029: telnet localhost 5029

Filtering

The filter box adapts to the input type. Available filters:

• Sensor - dropdown selection
• IP address/prefix - e.g., 192.168.%
• Phone number/prefix - e.g., 00 (international)
• Call-ID - exact or substring match

Filter Input	Matches
192.168.%	Source/destination IP starting with 192.168.x.x
00	Numbers starting with 00
abc123	Exact Call-ID match
%abc123%	Call-ID containing "abc123"

💡 Tip: Use % wildcard for substring matching in Call-ID searches.

Duplicate Entries

Duplicates often appear when calls traverse multiple SIP gateways/carriers.

Solutions:

• Filter by carrier IP - Enter the specific carrier IP to show only one leg per call
• Filter by sensor - If multiple sensors capture the same mirrored traffic
• SIP forking - Simultaneous ringing to multiple destinations are separate legs (expected behavior)

For distributed sensor architectures, see Sniffer_distributed_architecture.

IP also in proxy

(New in 2026.1) When filtering by IP address, enable the IP also in proxy checkbox to also match against proxy IP addresses in the call path.

This is useful when monitoring calls that pass through a specific SBC or proxy server, even if the caller/called IPs are different.

Show Call Info

Displays detailed SIP packet information for active calls when clicking on a call entry.

⚠️ Warning: Requires VoIPmonitor version 2024.09.1+ and can significantly increase CPU load.

Enable via config file:

# /etc/voipmonitor.conf
active_call_info = yes

systemctl restart voipmonitor

Enable via GUI: Settings > Sensors > wrench icon > enable active_call_info

Column Visibility

Customize visible columns via the column header menu ("Show columns"). Settings persist in the custom_config database table.

💡 Tip: Hiding problematic columns (e.g., "Proxy") can resolve performance issues caused by parsing errors.

Bottom Graphs

The bottom section displays top callers/called grouped by IP address.

Programmatic Access (API)

GUI API (Centralized)

Query active calls from all connected sensors via listActiveCalls:

curl -X POST 'http://yourserver/php/api.php?task=listActiveCalls&user=USER&password=PASSWORD&params={"sensorId":"1"}'

See WEB_API#listActiveCalls for details.

Sniffer Manager API (Direct)

Query a single sensor directly via port 5029:

echo 'listcalls' | nc localhost 5029

Method	Use Case
GUI listActiveCalls	Multiple sensors, centralized monitoring, external integrations
Manager API listcalls	Single sensor, local scripts, low-latency queries

Troubleshooting

Problem	Solution
No calls displayed	Verify port 5029 connectivity: telnet localhost 5029
Duplicate entries	Filter by carrier IP or sensor ID
Slow/unresponsive view	Hide problematic columns (e.g., "Proxy")
GUI completely frozen	Connect to DB, clear entries in custom_config table
Calls remain in active list after ended	Reduce sipwithoutrtptimeout (default 3600s) or rtptimeout (default 300s). Common when BYE packets are not captured (asymmetric routing, SPAN limitations).

For support tickets, provide:

• SIP PCAP dump of problematic calls
• mysqldump of voipmonitor.custom_config table

See Also

• Sniffer_distributed_architecture - Multi-sensor deployments
• WEB_API - Full API documentation
• Settings - Sensor configuration

AI Summary for RAG

Summary: Active Calls provides real-time monitoring of ongoing VoIP calls via TCP port 5029. Features include: live listening (G.711 only, sniffer v7+), filtering by IP/number/Call-ID/sensor, and column customization. Duplicate entries occur when calls traverse multiple carriers - filter by carrier IP to consolidate. "Show Call Info" feature (v2024.09.1+) displays SIP packet details but increases CPU load. Programmatic access available via GUI API (listActiveCalls for multi-sensor) or Manager API (listcalls for single sensor). Settings stored in custom_config table.

Keywords: active calls, real-time monitoring, live listening, G.711, port 5029, manager API, listActiveCalls, listcalls, call filter, duplicate entries, carrier IP, active_call_info, column visibility, custom_config

Key Questions:

• How do I view active/live calls in VoIPmonitor?
• Why are active calls not showing in the GUI?
• How do I filter calls by IP address or phone number?
• Why do I see duplicate entries for the same call?
• How do I enable "Show Call Info" feature?
• What port is used for active call data?
• How do I programmatically query active calls?
• What is the difference between listActiveCalls and listcalls?
• How do I customize column visibility?
• What version is required for SIP packet view in active calls?