Carrier-Grade VoIP Monitoring,
Recording & Troubleshooting

VoIPmonitor provides comprehensive call quality monitoring based on industry-standard metrics. Our system passively monitors your VoIP traffic and calculates real-time quality scores for every call.

Interactive 2D and 3D reports for MOS, packet loss, jitter, and PDV metrics with drill-down capabilities.

Key Metrics We Monitor

• MOS (Mean Opinion Score) - ITU-T G.107 E-model calculation predicting voice quality on 1-5 scale
• Jitter - Variation in packet arrival times affecting audio smoothness
• Packet Loss - Percentage of lost packets impacting call clarity
• PDV (Packet Delay Variation) - Network latency fluctuations
• R-Factor - Transmission rating factor for network quality assessment

Real-Time RTP Stream Analysis

Monitor the quality of each RTP stream in real-time. Visualize jitter, packet loss, and MOS score progression throughout the call duration.

RTCP Statistics

Leverage RTCP (Real-time Transport Control Protocol) data for accurate jitter and packet loss measurements reported directly by endpoints.

Packet-Level Deep Inspection

Drill down to individual RTP packets with Wireshark-like detail view. Analyze exact timing, sequence numbers, and identify specific packets causing quality degradation.

One-Way Audio Detection

Automatically detect and visualize one-way audio issues with comparative 2D and 3D graphs showing audio flow asymmetries.

Long-Term Quality Trends

Track quality metrics over time with trend analysis. Monitor ACD (Average Call Duration), ASR (Answer Seizure Ratio), NER (Network Effectiveness Ratio), and SEER for comprehensive service quality assessment.

Your secure, compliant, and fully automated communications archive. Capture and store 100% of your VoIP/RTC traffic for quality assurance, dispute resolution, training, and regulatory compliance.

High-Performance Storage Architecture

Our custom-designed serialized I/O format is specifically optimized for VoIP packet storage, enabling:

• Tens of Thousands of Concurrent Recordings - Store massive call volumes on standard rotating HDDs
• No SSD Required - Unlike random I/O patterns, our sequential writes maximize throughput on affordable magnetic storage
• Extreme Cost Efficiency - Scale to petabytes of recordings using commodity hardware

Multi-Tier Archival Storage

Build hierarchical storage architecture to optimize costs and access patterns:

• Hot Storage - Fast access for recent recordings on local drives
• Warm/Cold Tiers - Automatically move older recordings to secondary storage (NAS, SAN, cloud)
• Policy-Based Migration - Define rules for when and where to move recordings based on age or other criteria

What Gets Archived

Analysis runs on all traffic in real-time. Capture rules control only which packets get stored to disk. Define flexible archiving rules based on:

• IP Addresses - Filter by source/destination IP or subnet
• Phone Numbers - Match caller or callee numbers with wildcards
• Any SIP Header - Create rules based on any SIP header value (User-Agent, X-headers, etc.)
• Combinations - Combine multiple conditions for precise control over what gets stored

Archived Formats

• Audio Recordings - WAV, OGG, and MP3 formats with stereo (separate channels per party) for QA and training
• Full Packet Captures - Complete SIP/RTP PCAPs preserved for later forensic analysis
• T.38 FAX Archive - Automatic conversion of FAX transmissions to PDF documents

Supported codecs: G.711, G.722, G.723, G.726, G.729a, OPUS, AMR, AMR-WB, iLBC, Speex, GSM, Silk, iSAC, MP4A-LATM.

Compliance & Regulatory Standards

Meet strict industry regulations for call logging and retention:

• SIPREC Session Recording Server - Fully compliant SRS implementation (RFC 7866/7865)
• Dual Recording - Capture both legs of a call independently for complete coverage
• PCI-DSS Safe Recording - DTMF tone suppression and pause/resume API to prevent recording cardholder data
• Policy-Based Retention - Automated retention and deletion rules per your requirements

AI-Powered Call Transcription

Transform your call recordings into searchable text using OpenAI's Whisper speech recognition. Transcripts are stored per caller/callee with timestamps, enabling full-text search across all conversations.

• Per-Party Transcripts - Separate transcription for caller and callee with synchronized timestamps
• Automatic or On-Demand - Background transcription or click-to-transcribe from GUI
• GPU Acceleration - CUDA-powered processing with whisper.cpp for up to 30x faster transcription
• 99+ Languages - Automatic language detection with multilingual support

Your ultimate debugging toolkit. Go from customer complaint to root-cause in seconds. Drill down into any call with full SIP/RTP visibility, decrypt encrypted traffic, and export clean evidence for disputes and escalations.

Packet-Level Evidence

• Full SIP/RTP PCAPs - Access complete packet captures for any call
• Export to Wireshark - Download clean PCAPs for external tools
• Filtered Captures - Extract specific streams or time ranges

Signaling Analysis

Visualize and inspect the complete SIP message flow with interactive ladder diagrams.

• Ladder Diagrams - Interactive message sequence diagrams showing call flow
• Full SIP Headers - Every INVITE, BYE, and response with complete headers and SDP
• Timing Analysis - Identify delays between messages

Audio Analysis

Play back calls with visual waveform display and spectral analyzer. Identify audio issues at a glance.

• Waveform Display - Visual representation of audio streams
• Spectral Analysis - Frequency domain view to identify noise, echo, or codec issues
• Silence & Clipping Detection - Automatic detection of one-way audio and clipping
• Audio Reconstruction - Convert RTP streams to WAV/OGG/MP3 for playback

T.38 FAX Analysis

Convert captured T.38 FAX transmissions to readable PDF documents. Troubleshoot FAX failures by inspecting the complete T.38 session.

Encryption Support

• TLS Decryption - Decrypt SIP-TLS when keys are provided
• SRTP Decryption - Decrypt secure RTP streams for audio analysis
• SRTP Error Detection - Identify encryption/decryption failures and mismatches

Sharing & Collaboration

Share complete call records for collaborative troubleshooting with vendors, partners, or legal teams:

• Share via Your GUI - Generate shareable links within your own VoIPmonitor instance
• share.voipmonitor.org - Upload CDRs to our public sharing platform for collaboration with external parties
• Data Anonymization - Automatically anonymize sensitive data (phone numbers, IPs) before sharing

Reproducible Results & Evidence Export

All analysis is based on stored PCAPs, ensuring results can be reproduced and verified at any time. Export complete evidence packages for SLA disputes, legal proceedings, or compliance audits.

Real-time visibility into your VoIP infrastructure. Monitor active calls, analyze quality instantly, and react to issues before customers notice. Comprehensive alerting catches problems and fraud attempts the moment they occur.

Live Views for NOC Operations

• Live Call View - Real-time display of all ongoing calls with instant quality metrics (MOS, jitter, packet loss)
• Live Group by IP/Src/Dst/Number - 3D quality graphs showing RTP metrics across all active calls - ideal for NOC dashboard instant overview
• Live Packet Sniffer - Capture packets for ongoing calls without waiting for call completion - instant signaling debug
• Real-time Concurrent Calls - Monitor active call count per IP or phone number in real-time

Live Packet Sniffer - capture packets for ongoing calls without waiting for completion

3D Dashboard with MOS, Packet Loss, Jitter, Concurrent Calls, Minutes, SIP Responses, NER, ASR

Comprehensive Alerting System

• Flexible Filter Combinations - Build any alert rule from CDR data fields with custom thresholds
• KPI Alerts - CPS, ASR, NER, SEER, ACD, PDD monitoring with configurable thresholds
• Timeout Alerts - Various timeout types (no answer, post-hangup, RTP inactivity, stalled call)
• Trend Anomaly Detection - Alert when data deviates from historical patterns - uses pre-computed data for instant detection even in high-traffic environments

Fraud Detection Rules

• Real-time Concurrent Call Limits - Detect sudden spikes in simultaneous calls per IP/number
• Geographic Anomalies - Alert on CDR country changes or SIP registrar country changes
• Attack Detection - SIP flood detection, register attacks, sequential fraud call patterns
• Billing Alerts - High-cost destination calls, billing quota exceeded per IP/number
• Registration Monitoring - Alert when registered device count changes significantly

Alert Channels: Email, SMS, webhook, or custom integrations. All alerts include full context for immediate action.

Transform your CDR data into actionable insights. Build custom dashboards, analyze trends across millions of records instantly, diagnose call issues, and schedule automated reports - all with a system designed for carrier-scale data volumes.

CDR Drill-Down & Contextual Trends

• Instant Contextual Trends - From any CDR record, instantly view historical trends for that IP or phone number
• One-Click Analysis - All graphs and metrics available as context menu options - no navigation required
• Pattern Recognition - Quickly identify if an issue is isolated or part of a larger trend

CDR drill-down: 7-day trends for MOS, packet loss, jitter, concurrent calls, minutes, SIP responses, NER, ASR, CPS, ACD, SEER, billing

Custom Dashboards

• Fully Customizable Views - Build dashboards tailored to your metrics - RTP quality, signaling stats, or combined views
• 2D & 3D Visualizations - Charts, graphs, and 3D representations for intuitive data exploration
• Data Direct from CDR - All visualizations pull live data from your call detail records

Dashboard panels: total calls, PDD, MOS, jitter, countries, minutes, load, 3D trends

Dashboard with MOS distribution, SIP responses, and real-time MOS/jitter/packet loss

Instant Analytics with OLAP

• Automatic OLAP Generation - Pre-computed aggregations for instant trend visualization regardless of database size
• Tens/Hundreds of Millions of Records - No waiting - instant results even with massive datasets
• Per-IP/Number Trend Storage - Separate data stores for instant per-entity trend analysis

Trends for CC, CPS, minutes, ACD, ASR with weekly 3D overview

KPI trends: minutes, ACD, ASR, NER, SEER with detailed ASR breakdown

Key Metrics

• RTP Metrics - Jitter, packet loss, MOS, RTCP XR data, silence/clipping audio detection
• Signaling Metrics - ACD, ASR, NER, SEER, CPS, concurrent calls per IP/number
• Billing Data - Cost analysis, revenue tracking, margin calculations

Call Diagnostics

Call diagnostics: quality trends (MOS, jitter, loss) and issue distribution (one-way audio, no audio, timeouts)

Quality & Connection Issues:

• MOS Compare, One-Way Audio, No Audio (Missing RTP), Missing SRTP Key
• False Answer Supervision (FAS), Invalid RTP Stream, SIP ALG Interference

Call Flow Issues:

• Improper Hangup (Missing BYE), Missing BYE Acknowledgment, One-Way Signaling
• Various Timeouts: Absolute Duration, Post-Hangup, RTP Inactivity, No Answer, Stalled Call
• Early Hangup, Answered Without Audio, SIP Packet Limit, Sniffer Shutdown

Scheduled Reports

• Any Dashboard as Report - Convert any dashboard view into a daily or weekly scheduled report
• Historical Archive - Reports automatically saved for easy historical access and comparison
• Multiple Formats - 2D/3D graphs, trend analysis, summary tables
• Role-Based Access - Different views for NOC, support, and management teams

Built-in billing engine rates every call in real-time. Track customer revenue and carrier costs side-by-side. Use billing data for fraud detection with simple rules that catch most attack patterns, or as an independent verification of carrier invoices.

Flexible Price Tables

• Complex Rate Structures - Define rates by destination prefix, time of day, call duration brackets, and connection fees
• Multiple Price Tables - Create separate billing tables and assign them to specific IPs, phone numbers, customers, or trunks
• Customer vs. Carrier Pricing - Maintain both revenue (what customers pay) and cost (what you pay carriers) price tables to calculate margins
• Automatic CDR Rating - Every call is rated in real-time against the applicable price table

Price table configuration with destination prefixes, per-minute rates, connection fees, and billing increments

Revenue & Cost Tracking

• Dual-View Analytics - See customer-billed amounts alongside carrier costs for every call, route, or time period
• Margin Visibility - Instantly calculate profit margins per destination, customer, or trunk
• Dashboard Integration - Billing amounts displayed in 2D/3D trend graphs with historical comparisons
• Scheduled Reports - Daily, weekly, or monthly billing summaries delivered via email with full breakdown

Weekly billing trends showing minutes and costs with historical low/high boundaries for instant anomaly detection

Billing-Based Fraud Alerts

• Quota Limits per IP/Number - Set hourly, daily, weekly, or monthly spending limits per source IP or phone number
• Generic Rules, Maximum Coverage - A few simple quota rules catch most fraud scenarios without complex configuration
• Instant Alerts - Get notified immediately when any entity exceeds its billing threshold
• Combine with Other Indicators - Layer billing alerts with concurrent call limits, destination changes, and registration anomalies

Alert configuration: trigger when any source IP exceeds $20/hour, $100/day, $1000/week, or $2000/month

Independent Billing Verification

Use VoIPmonitor's billing data as a backup verification mechanism for carrier invoices. Compare your calculated costs against what carriers bill you to catch discrepancies, billing errors, or unexpected rate changes. Having an independent record of every call with your own rating provides leverage in billing disputes and ensures you're never overcharged.

The sniffer is engineered to maximize multi-core CPU utilization, capable of processing 10 Gbit VoIP traffic on a single server. Tested and running in production environments with over 100,000 concurrent calls.

Multi-Core Performance

• 10 Gbit Processing - Full line-rate VoIP traffic analysis on a single server with multi-core optimization
• 100,000+ Concurrent Calls - Tested and deployed in carrier-grade environments with massive call volumes
• Standard 10Gbit NICs - Works with commodity Intel network cards using native Linux capture or DPDK kernel-bypass
• DPDK Acceleration - Optional kernel-bypass packet capture for maximum throughput when needed
• Napatech Support - Hardware timestamping NICs supported, though not required thanks to DPDK efficiency
• ARM Architecture - Native support for ARM-based servers and embedded devices

Horizontal Scaling

• Distributed Architecture - Scale by deploying multiple independent sniffers writing to a central database
• Central GUI - Single web interface aggregates data from all distributed capture nodes
• 50,000 CDR Writes/Second - Database model optimized for extreme write throughput
• Serialized Packet Storage - Optimized format minimizes storage costs while maintaining full packet fidelity, ideal for cost-effective storage media

Flexible Deployment

• Port Mirroring - Passive capture via SPAN, RSPAN, or ERSPAN from network switches
• Direct Analysis - Deploy directly on SBC, PBX, or media gateways for integrated monitoring
• Virtual Machines - Run in VMware, KVM, Hyper-V, or any hypervisor environment
• Cloud Native - Full support for AWS, Google Cloud, Microsoft Azure, and all major cloud platforms
• Hybrid Deployments - Combine capture methods across on-premise and cloud infrastructure

Proven at Scale

Used by carriers and large enterprises worldwide. Our architecture has been refined over years of production deployments handling billions of calls with ultra-thin resource footprint.

Deploy as a passive sniffer on bare metal, in VMs, or the cloud. Capture traffic via multiple methods and integrate with any RTC environment.

Capture Methods

• SPAN/Port Mirroring - Passive capture via switch mirror port
• RSPAN - Remote SPAN across VLANs
• ERSPAN - Encapsulated Remote SPAN over IP/GRE
• Network TAP - Hardware tap for guaranteed capture
• SBC-Native Mirroring - Packet duplication from AudioCodes, Ribbon, Oracle SBC, Cisco CUBE, Sangoma, Dialogic

Protocol Support

• SIP - Full SIP message parsing and call correlation
• RTP/RTCP - Audio stream capture and quality analysis
• WebRTC - Browser-based real-time communication
• MGCP - Media Gateway Control Protocol
• SKINNY/SCCP - Cisco proprietary signaling

Tested Interoperability

• SIP Proxies - Kamailio, OpenSIPS
• Media Servers - FreeSWITCH, Asterisk
• Enterprise PBX - Cisco, Avaya, Genesys, Mitel
• Session Border Controllers - AudioCodes, Ribbon, Oracle SBC, Cisco CUBE, Sangoma, Oigaa, Odin/Ooma
• UCaaS/CCaaS Platforms - NetSapiens, Oigaa, BroadSoft, Odin

VoIPmonitor works with any system using supported protocols - if it speaks SIP, RTP, or WebRTC, we can monitor it.