Overview | Main Features | Waverform/ Spectral Viewer
VQT Results | Screenshots | Buyer's Guide

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Overview

Testing on the extreme end-point of a VoIP softphone network has become a priority for many service providers. This method of testing represents what an end user is actually experiencing.

Voice quality testing within VoIP networks is growing; a major concern is testing VoIP softphones that will be used with VoIP networks. The GL VQuad™ software combined with GL's Voice Quality Testing (VQT) software permits this desired VQT testing, of the VoIP equipment, yielding results that include PESQ/PAMS/PSQM+ Mean Opinion Scores (MOS). These results provide an excellent overall measure of voice quality of the equipment under test.

The VQuad™ with VoIP option provides the ability to perform manual or automated tests on the VoIP network. The VQuad™ provides direct connection to the VoIP network with up to eight instances connected simultaneously. Using the VQuad™ software, the user may configure automatic call control (SIP protocol) along with automatic generation/reception of voice files. Path confirmation using digits or frequency tones is also available in an automated or manual operation.

The GL VQT utilizes three widely accepted algorithms to perform the voice comparisons, the Perceptual Evaluation of Speech Quality (PESQ LQ/LQO) per Rec. P.862/P862.1, the Perceptual Analysis / Measurement System (PAMS) per Rec. P.800, and the Perceptual Speech Quality Measurement (PSQM) per Rec. P.861. PESQ provides an objective measurement of subjective listening tests on telephony systems. PAMS predicts overall subjective listening quality (a human's perception of quality) without requiring actual subjective testing (a very expensive and time-consuming process). PSQM predicts subjective quality of speech codecs without requiring subjective testing. The GL VQT performs PESQ, PAMS, and PSQM (+) simultaneously, using two voice files (Reference File and Degraded File) and provides the algorithm results along with analytical results in both a graphical and tabular format.

Additional Information

• VQT Software
• VQuad™ (Formerly AFT)
• Testing Analog Telephone Adapters (ATAs)
• Testing VoIP, Analog and Digital Phones

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Main Features:

• Connect at endpoint of a VoIP network
• Up to eight instances connected to a single system
• Automatic call control (SIP protocol) with user-defined parameters for authentification and proxy
• Automatic send/receive of voice files over already established calls
• Time/Digit/Tone triggering of send/receive voice files.
• Compact and portable solution for testing end-to-end voice quality
• Synchronized software for sending/recording of voice files at multiple locations
• Flexible architecture and features for recording locations, parameters, and time
• GL VQT Automatic Mode allows automatic execution of the VQT algorithms (PESQ, PAMS, PSQM+).
• Additional measurements include Clipping, Jitter, Latency, Noise and Signal Levels.
• Results available in real-time or post-processing

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Waveform/Spectral Viewer

The GL VQT software can be user-configured to provide a rating of each measurement based on the MOS, latency, clipping, etc. A poorly rated measurement can be viewed in graphical format using the waveform viewer. Dropouts, noise and other impairments can be examined here.

Screen Shot of Waveform/Spectral Viewer

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Voice Quality Testing (VQT) Results

GL's VQT may be executed automatically (real-time and/or post-processing) or manually by entering a Reference File and Degraded File. Regardless of how GL's VQT is initiated, algorithms for PAMS, PSQM, PSQM+, PESQ MOS and PESQ LQ are executed simultaneously for the two voice files and results are shown graphically as well as in a tabular format. GL's VQT also displays cumulative statistics for large scale testing over long periods of time.

Screen Shot of PESQ Measurement Window

Screen Shot of VQT Measurement Results

Screen Shot of VQT Cumulative Statistics

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Screenshots

• VQuad™ Device Settings
  
  
• VQuad™ VoIP Settings

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Buyer's Guide:

Item No.	VQuad™ Network Options
VQT010	VQuad™ Software (Stand Alone)
VQT020	VQuad™ Wireless Phone Call Control
VQT012	VQuad™ Analog FXO 4-port Call Control
VQT013	VQuad™ with SIP (VoIP) Call Control
VQT015	VQuad™ with T1 E1 Call Control
Item No.	VQuad™ Miscellaneous
VQT202	VQuad™ GPS Location and Timing Option (per node - including GPS receiver)
VQT030	Network Command Center (Multi-Node Command and Control Center for VQuad™ Systems)
VQT240	Universal Telephony Adapter (UTA) with Round Trip Delay Measurement
VQT250	High Quality USB Audio Capture Unit
VQT300	Portable Wireless Enclosure Kit
Item No.	VQT
VQT002	Voice Quality Testing (PESQ only)
VQT004	Voice Quality Testing (PAMS, PSQM, PESQ)
VBA032	Near Real-time Voice-band Analyzer

* Specifications are subject to change without notice.

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