Mean Opinion Score (MOS) is a test used in telephony networks to obtain a human user's perspective of call quality in a particular network. Customers can obtain MOS scores for their networks by visiting: Will my internet connection and network support high quality VoIP calls?
MOS Score Summary Reference:
1 - Unsatisfactory - Very annoying distortion which is objectionable
2 - Poor - Annoying distortion but not objectionable
3 - Fair - Perceptible distortion that is slightly annoying
4 - Good - Slight perceptible level of distortion but not annoying
5 - Excellent - Imperceptible level of distortion
What Customers should expect:
A MOS score of 4 is very optimal for a G711 codec call, which is a standard codec, and is comparable to Toll quality. A score of 5 is a rare occurrence and not receiving scores in the range of 5 is not a disqualifier for a high quality voice experience, as well as VoIP in general.
Most customers using BYOB (Bring Your Own Broadband) can expect a rating of 3.3 - 4.2 in non-congested converged networks. Customers with heavily congested networks will see ratings of 1 - 3.1; in those scenarios we highly recommend considering a dedicated internet connection for the phone service, or the implementation of Quality of Service (QoS) on customer networks.