There are two methods by which Spearline can perform PSTN Quality tests;
Method 1: Audio Quality Testing via hidden DTMF
Spearline will provide an audio test prompt, which you must upload to your IVR system. A hidden DTMF option needs to be added to your IVR, which is not listed in thecustomer-facing announcement; Only Spearline is aware of the DTMF code.
- Spearline generates a test call and, once connected, sends the hidden DTMF option, which will connect our call to the audio test prompt.
- Our audio test prompt needs to play in full, and Spearline will then generate an audio-quality PESQ score.
Method 2: Audio Quality Testing via CLI Lookup
Spearline will provide an audio test prompt to you which you must upload to your IVR system. Spearline will provide you with a list of the CLI’s that will be use to generate each test call. Each country that we test in has its own specific CLI.
- The customer will whitelist Spearline CLI’s
- Upon receipt of a call from one of these CLI’s , the call will be redirected to the location of our audio quality prompt.
- Our audio test prompt needs to play in full, and Spearline will then generate an audio quality PESQ score.
- Depending on your IVR infrastructure, you may be able to upload the prompt on a centralized IVR that will apply the hidden DTMF option to all of your numbers. We would recommend engaging with a member of your IVR team to discuss if this is an option.
- The audio test prompt is a WAV file with a bit rate of 128kbps. If this is not compatible with your IVR system, please let us know what format you require and we will provide it to you. Altering the prompt in any way could have a detrimental effect on the audio quality which would then be reflected in your testing results. Also, please note that the prompt has 5 seconds of silence before and after our prompt plays. Please ensure that this silence is not cut from the prompt as we use silence detection to determine when to begin and end the audio quality analysis.