You know, this is a great question and one that we answer based on both quantitative and qualitative planes. See, quality at the interconnect voice level, is a little different than quality at the subscriber level. Many of you probably remember those Sprint commercials where they would tout their ability to provide such high voice quality that you could, “hear a pin drop”. To support that, service providers in the 80s and 90s invested heavily in the TDM network to ensure that quality was delivered to the end user. Some say that there was a lot of over-engineering in the TDM network and that we passed the point of diminishing returns relating to voice quality improvements.
Whether that is true or not, it is irrelevant to the domain of interconnect voice quality. See, in interconnect voice, quality is measured more on a macro level. Of course, every carrier wants to provide excellent quality on every call, but, in a VoIP/SIP dominated world, that rarely works out. So, service providers look at more macro level numbers, and tend to worry less about individual calls. As a result, GCS has built its QoS management capabilities to reflect this value system that carriers place on interconnect voice quality. Of course we measure all the standard things: PDD, ALOC, ASR, ABR, NER, but we don’t measure MOS scores, and we allow our carriers to establish thresholds with a premise of volume.
This way, carriers can respond to real network issues as opposed to one-off complaints by individual callers. Those are important, but at the interconnect level you need to manage network or destination based quality issues, and leave the individual caller problems to a lower priority. It’s something retail carriers struggle with, but is easier at the interconnect level.
Have a great day,