In the original blog from 2010, VoIP was under attack by traditional carriers as suffering from poor quality and reliability. That is no longer the case. In fact, as I increased my U-verse bandwidth recently, the sales person spoke very well of the AT&T VoIP service. If I was not an employee of a VoIP provider, I might have been an eager convert. So, FUD or the use of Fear, Uncertainty and Doubt is no longer an impediment to the growth of VoIP and SIP Trunks. However, questioning the voice quality of VoIP seems to still have legs.
Using something called the Mean Opinion Score (MOS) we are able to determine with a measure of accuracy voice quality over varying connectivity methods. To establish a MOS, listeners (in the case of the study I am quoting 30 to 50 people) listen to speakers of both sexes read specific sentences. Each listener then rates each sentence as follows: (1) bad; (2) poor; (3) fair; (4) good; (5) excellent. The arithmetic mean of the individual scores is the MOS. The International Telecommunication Union (ITU) endorses this testing method. Here are some of the suggested sentences:
- You will have to be very quiet.
- There was nothing to be seen.
- They worshipped wooden idols.
- I want a minute with the inspector.
- Did he need any money?
On a scale of 1-5 where 5 is excellent, VoIP with a G.711 codec and a long distance toll call come out equal with 4.4 each. Even the G.729a codec beats a cell phone call with 4.2 versus 3.8.
Software tools have been developed that automate MOS testing. These tools do a better job of evaluating network conditions and codecs more consistently than human listeners.
So, inform your prospects and customers that VoIP/SIP Trunking is as good as your current phone service and with Broadvox and other ITSPs, you can save up to 70%.
See you on Monday.