#Call #audio: #Impairments #analysis, #patterns, problem #rootcause #discovery, #bigdata analysis
Sevana #libraries collect all the #data described below in #realtime providing immediate #alerting and #storage of all #metrics related to #call #audio #degradation. #Audio #impairments one can map on #network #parameters that will form #patterns related to certain #routes, #destinations, #originations. Every #call analyzed by the #system creates #data that one can study using #bigdata #analysis tools to #predict #network #behavior and #call #quality.
Silent Call – one leg of the voice call has no speech (#silentcall)
#Echo – this is typically due to a blockage or mismatch, which results in the signals bouncing back from where they came. Additionally, the presence of echo effect in packet switched networks can be traced back to the functionality of the line. Where standard lines function with a delay of 10 milliseconds, packet switched networks can have up to 400 milliseconds of delay. As a result, the echo effect is that much more noticeable.
#Amplitude #clipping – is typically a results of a misconfigured voice gateway on the voice path.
#Dynamic #clipping – notifies about possible clipping happening in another network as the audio waveform corresponds amplitude clipping, however, it is not present at the moment.
#VAD #clipping - this impairment detects incorrect work of Voice Activity Detector (VAD). Detector finds edges of active and inactive fragments of the signal considering VAD worked too late (in the beginning of the speech) or too early (in the end of the speech).
#Click – is a single energy spike in the spectrum of the audio, which may happen for different reasons.
DeadAir-01 – is a zero signal level inside speech, a gap in speech that may be caused by different reasons.
DeadAir-00 – is a constant signal level inside speech and may have positive and negative value.
#SNR – this means that noise level present in the call affects human perception and disturbs the caller.
#Patterns:
Click + DeadAir-01 – high probability that packet loss affected the call audio
Click + VAD clipping – possible packet loss