VoIP Audio Quality is Better, says Minacom (Tektronix)

Since late last summer, VoIP phone service has sounded better and connected faster than the public phone network, according to data collected by Minacom (Tektronix). Results show that VoIP service quality has increased steadily, with an average Mean Opinion Score (MOS) of 4.2, compared to 3.9 for the PSTN (scores range from 1 (worst) to 5 (best). Based on a MOS threshold of 3.6, only 1 out of 50 calls in North America were considered to be unacceptable (about 1 in 10 worldwide)while greater than 85 percent of VoIP calls exceeded average PSTN quality. In addition to superior sound quality, calls over VoIP connected quicker overall (8.2 seconds on average, compared to 8.9 seconds for those placed over the PSTN).

As happy as you might be about improving VoIP audio quality, uou might wonder about the performance of the public network. There are a couple of things at work here. First, lots of calls are now mobile to mobile or have mobile on one end. That automatically hits quality. The other thing is that perhaps a majority of international calls are terminating at one end in parts of the world where the public network simply isn't very good. In those cases, VoIP often does sound better.

Even though VoIP might sound better than the public network on average, including all calls to areas with poor public networks, the same sort of MOS score distribution probably wouldn't be seen so much for intra-country calls in North America, Europe or parts of East Asia. The other thing is that calls arguably traverse more networks and network elements now than was typical in the past. That can't help, and can harm, audio quality, as impairments accumulate.