About VOIPMonitor

VOIPMonitor is network packet sniffer with frontend for SIP RTP RTCP SKINNY(SCCP) MGCP WebRTC VoIP protocols running on linux.

VoIPMonitor Dashboard VoIPMonitor Dashboard

VOIPMonitor is designed to analyze quality of VoIP call based on network parameters - delay variation and packet loss according to ITU-T G.107 E-model which predicts quality on MOS scale.

VoIPMonitor Listening Call VoIPMonitor Listening Call

Optionally each call can be saved to pcap file with either only SIP protocol or SIP/RTP/RTCP/T.38/udptl protocols.

VOIPMonitor can also decode speech and play it over the WEB GUI or save it to disk as WAV. Supported codecs are G.711 alaw/ulaw, G.726 G.722 G.729a G.723 iLBC Speex GSM Silk iSAC OPUS AMR.

VoIPMonitor Packet Loss Monitoring VoIPMonitor Packet Loss Monitoring

VOIPMonitor is also able to convert T.38 FAX to PDF.

VOIPMonitor is proven industry leading solution used by the largest VoIP service carriers and call centers

Usages of VOIPMonitor

  • Monitor and troubleshoot quality of SIP VoIP calls
  • Archive all calls including SIP, WebRTC, SKINNY RTP, SS7 over SCTP, T.38 and T.30 FAX (PDF) in CDR database
  • Decode and play calls directly from the GUI or show T.38 FAX as PDF
  • Anti fraud / watchdog rules to prevent fraudulent calls
  • Monitor call centers
  • Billing purpose
VoIPMonitor RTP Analysis VoIPMonitor RTP Analysis


  • Supported transports: UDP TCP (robust passive TCP reassembler)
  • Output: CDR, full SIP/RTP pcap, WAV OGG audio, T.38 PDF FAX
  • Digital signal processing: voice decode / spectral analyses / silence and clipping analyses / FAS detection / DTMF detection
  • Comprehensive statistics / charts / dashboards
  • Alerting
  • Anti-fraud
  • Billing
  • Multi-user Multi-role access
  • Recognises UK and Europe ringing tones (FAS - false answer detection)
  • Decryption support
    • SIP and RTP decryption
    • Supported protocols: SSLv3 TLS 1.0 1.1 1.2 1.3
    • All cypher suits in openssl
    • All linux software using openssl (tested with Kamailio Opensips Freeswitch Asterisk SipXecs OpenUC)
    • Proprietary SIP stacks using non DH cypher suits or DH cypher suits (wireshark session key log must be supported by vendor)
VoIPMonitor Realtime RTP Metrics VoIPMonitor Realtime RTP Metrics


  • VOIPMonitor is a passive analyser which can decode any software and hardware based SIP
  • VOIPMonitor is tested and used to monitor all major opensource SIP platforms (Kamailio Opensips Freeswitch Asterisk SipXecs OpenUC)
  • VOIPMonitor is tested and used by major proprietar SIP PBX/SBC
  • VOIPMonitor can run on any hardware running linux including all virtual and cloud platforms
  • VOIPMonitor sniffer can run directly on the linux SIP host or as a dedicated virtual or physical hardware listening to mirrored packets (Switch mirroring / TAP)

Scaling VOIPMonitor

  • Unique VOIPMonitor architecture allows to analyse over 100 000 concurrent calls on a single server and more than 80 000 calls per second
  • Unique IO architecture allows to store pcap files for every single call (more than 100 000 concurrent calls) without a need for fast storage (unique internal voipmonitor storage format ensuring serial writes)
  • Client - Server architecture allows horizontal scaling (adding more servers)