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Embedded VoIP Quality Monitoring Technology for IP Phones and IP/TDM Gateways

Example Use of VQmon/EP for
Enterprise VoIP Performance Monitoring

Specifically designed for integration into VoIP endpoints such as media gateways, IP phones, ONUs, residential gateways, mobile handsets, traditional TDM gateways, and hybrid IP/TDM systems, VQmon®/EP monitors voice calls and produces call quality estimates that can be reported as MOS scores and R factors through the media path using RTCP XR (RFC 3611) and SIP RTCP Summary Reports (RFC 6035).

VQmon/EP detects packet loss and jitter buffer discard events, extracts key information from DSP software, and produces real-time call quality scores and diagnostic data. VQmon/EP is widely used in the industry and has been integrated into the products of over 50 equipment manufacturers, among them Voice over IP solutions from Texas Instruments and Global IP Solutions.

VQmon/EP generates listening and conversational quality MOS scores and R factors and a wide range of diagnostic data, making these available through an API as raw metrics, RTCP XR, and SIP RTCP Summary Report payloads. In addition, VQmon/EP provides real-time call quality thresholding, supporting either alert generation or automatic configuration.

VQmon/EP uses an advanced VoIP perceptual quality estimation algorithm that incorporates support for key international standards including ITU-T P.564, ITU-T G.107, ITU-T G.1020, ETSI TS 101 329-5 Annex E, and IETF RFC 3611 and RFC 6035. VQmon/EP includes measurements of time-varying IP impairments (typically caused by network congestion) and has been independently shown to provide significantly more accurate and stable metrics than other algorithms such as G.107 (the E-model).

VQmon/EP Features and Specifications

VQmon/EP Architecture
  • Compact code size - 6-30 Kbytes
  • Efficient processing - <500 instructions per second
  • Listening and Conversational Quality MOS scores (MOS-LQ, MOS-CQ)
  • Listening and Conversational Quality R factors (R-LQ, R-CQ)
  • Burst and Gap Call Quality Scores (R-Gap, R-Burst)
  • Narrowband and Wideband R factor and MOS Scores
  • Degradation factors - reports severity of quality degradation due to packet loss, discard, delay, codec, and other factors
  • Supports RTCP XR and SIP RTCP Summary Reports
  • Burst and Gap Loss/Discard Statistics
  • Supports VoIP, TDM, and hybrid TDM/VoIP applications
  • Support for packet, frame, and time-based jitter buffers
  • Support for a wide range of ITU, cellular, industry-standard, and proprietary codecs
  • Cumulative and Interval Metrics
  • Complies with or supports ITU-T P.564, G.107, ETSI TS101329-5 Annex E, RFC 3611, RFC 6035


For more information, see the VQmon/EP Product Brochure or contact Telchemy.

Information on VQmon Accuracy

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