VoIP quality claimed to beat PSTN - worldwide

Stuart Corner
Tuesday, 29 August 2006 08:07

Business IT - Technology

According to testing company, Minacom, VoIP phone service worldwide "now sounds better and connects faster than the standard public-switched phone network (PSTN)." However this achievement does not extend to the likes of Skype and GoogleTalk.
Minacom says that data collected over the last 12 months by its standards-based, single-ended service quality test system show that the quality of VoIP services offered by telcos, cable operators, and broadband VoIP providers has increased steadily over the past year, with an average Mean Opinion Score (MOS) of 4.2, compared to 3.9 for the PSTN. MOS, an International Telecommunication Union standard, is commonly used to describe speech quality. It ranges from 1 (worst) to 5 (best).

Minacom says that "Based on a MOS threshold of 3.6, only one out of 50 calls in North America were considered to be unacceptable - one in 10 worldwide - while greater than 85 percent of VoIP calls exceeded average PSTN quality over the same period."

Minacom refuted the results of recent Internet phone quality study  by rival testing organistion Brix Networks which it says found that 1 in 5 calls were unacceptable, and that call quality was steadily declining.

According to Minacom, the Brix report "evaluated computer-to-computer (PC-PC) Internet phone service, similar to those offered by Skype, Google Talk, MSN and Yahoo Messenger...The quality and service reliability of these applications does not compare to that of the VoIP phone services offered by telcos, cable operators, and broadband VoIP providers who carefully deploy, monitor and manage the quality of their services.

"PC-PC VoIP quality is subject to many diverse impairments, including firewall settings, computer performance, antivirus installations, high-compression codecs, and Internet bandwidth shared with gaming, file downloads, web surfing and email. By contrast, VoIP offered by service providers is switched using telecom grade equipment, uses lower-compression codecs, and is prioritised over regular Internet traffic using sophisticated, standards-based multimedia telephone adapters (MTAs), maintained and monitored by the operator."

Minacom says its tests were conducted over PSTN, managed broadband and cable VoIP lines, the same services offered to residential and enterprise customers by phone, cable and hosted VoIP providers. "Each month, Minacom's PowerProbe 6000 service level test probe places hundreds of calls from Minacom's QoS labs in Montreal, Canada, to public destinations worldwide over PSTN, broadband VoIP, cable VoIP, DSL, FTTP and wireless networks."

The results are published in the Minacom QoS Benchmark Reports, a email newsletter now in its fourth year of circulation and available free to "qualified members of the telecommunications industry."