VOIP services

Report Hisses at VOIP Quality

The overall reliability of VOIP service has improved over the past six months, a new study shows, but VOIP calls still feature much more jitter, hiss, and delay than circuit-switched calls.

The study, conducted by California-based research house Keynote Systems Inc. , focused on two main factors -- the reliability and the sound quality of VOIP calls. During the last six weeks of 2005, Keynote set up servers to place 190,000 VOIP calls in and between San Francisco and New York City using the top 11 U.S. consumer VOIP services. (See Yankee Points to VOIP QOS.)

While the sound quality of a few VOIP providers has improved over the past six months, most VOIP providers still offer services with less sound quality than both wireline and cellular service, Keynote says. Service from just three providers -- Vonage Holdings Corp. (NYSE: VG), Time Warner Cable Inc. (NYSE: TWC), and Verizon Communications Inc. (NYSE: VZ) -- now sound good enough to be called “toll quality.” Five of the 11 providers in the study -- Keynote wouldn’t name names -- aren’t even close to reaching that standard yet. (See Empirix Upgrades VOIP Tracker.)

To underline the importance of sound quality, Keynote points out that 52 percent of respondents in a recent Harris Interactive survey named call quality as a key reason not to use VOIP. Other reasons included lack of E911 service and security and privacy worries.

Keynote says delay on VOIP calls has proved a persistant problem for many providers. VOIP callers hear up to twice as much audio delay as callers using a traditional phone service. More troubling is Keynote's finding that the delay problem hasn't improved since the firm's last VOIP study back in June 2005. (See Survey: VOIP Quality Is Breaking Up.)

“I’m still surprised that six months later, when we look at audio data from VOIP providers, we still see the improvement in audio quality and delay as considerably poor," Keynote product manager Dharmesh Thakker told Light Reading this week.

In terms of reliability, or the likelihood that a call will connect successfully, VOIP calls from the 11 providers had an overall connection rate of 99.1 percent. That's up from 97 percent last June, but still far from the “five nines” of reliability consumers have gotten used to.

VOIP service from Vonage and Time Warner Cable were found to be most likely to connect, with the least amount of dial attempts and dropped calls.

The 11 VOIP services included in Keynote’s study were Time Warner Inc. (NYSE: TWX) division AOL’s TotalTalk, AT&T Inc. (NYSE: T) CallVantage, EarthLink Inc. (Nasdaq: ELNK) trueVoice, 8x8 Inc. (Nasdaq: EGHT) Packet 8, Primus Telecommunications Inc. Lingo, SunRocket Inc. , Time Warner Digital Phone, Verizon VoiceWing (NYSE: VZ), via:talk, Vonage and Vonics Digital Data.

Keynote says Time Warner Digital Phone is the overall best VOIP service provider in both reliability and audio clarity. (See Cable Is the Voice of VOIP.) The cable product edged out Vonage and AT&T CallVantage, which ranked one and two in the June study. Keynote says it found a significant gap in both reliability and audio clarity between Time Warner Digital Phone and the lowest-ranking providers in the study. (See Cable Crowd Seeks VOIP Peers.)

The researchers also found that the broadband network underlying the VOIP service had a lot to do with the way the service performed. (See QOS Fees Could Change Everything .) The VOIP calls Keynote studied were placed over three different broadband networks in each city -- Time Warner Cable, Sprint Corp. (NYSE: S), and Verizon DSL in New York and Comcast Corp. (Nasdaq: CMCSA, CMCSK), SBC DSL and the Sprint business-class network in San Francisco.

Keynote says Verizon DSL proved to be the most reliable network for connecting VOIP calls, while the Time Warner Cable network promoted the best audio clarity.

By most accounts, VOIP usage rates are rising quickly in the U.S. Still, as the Keynote researchers suggest, the VOIP business is a low margin affair and customer retention is key to survival. (See Vonage Hearing Buy-Out Bids.) “The number one take away for the industry is that audio quality still needs to be improved significantly,” Thakker concludes. “[VOIP providers] have done a great job of improving reliability, but just keeping their service available doesn’t mean that consumers are going to be satisfied.”

— Mark Sullivan, Reporter, Light Reading

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OldPOTS 12/5/2012 | 4:07:56 AM
re: Report Hisses at VOIP Quality Well there are solutions for the voice quality problem, like QoS, but that cost big $$$.
So will there be improvements? Or will the business case with low margins be to serve only those people that will accept the lower quality?

But at what price?????

stephencooke 12/5/2012 | 4:07:56 AM
re: Report Hisses at VOIP Quality Hi,

This was in the Globe & Mail today:

unlimited 12/5/2012 | 4:07:55 AM
re: Report Hisses at VOIP Quality The obsession with VoIP telephony seems misguided to me. VoIP over the Internet (general purpose data network) cannot match performance of the purpose built PSTN. Not in the near future anyway. But it seems like the wrong approach for VoIP. VoIP should be used for applications that are not suited to the PSTN. In theory, if you build voice applications that don't easily compare to telephony, there is a chance to re-invent voice communications in a less threatening environment.

If history is anything to go by, making the most of new technology is usually most successful when its unique properties are exploited, not when it is used to incrementally improve an existing product or service.

Often when you try to apply new technology to an existing problem it appears to need a lot of investment to make it good enough to replace the prior technology.
netsalesman 12/5/2012 | 4:07:54 AM
re: Report Hisses at VOIP Quality Liked the article a lot. Just a thing about sound quality: how come that skype quality is so high (much higher than POTS or PSTN which is indeed quite poor being just limited to a 8Khz spectrum) ? Why don't provider use the same codec as skype?

netsalesman 12/5/2012 | 4:07:53 AM
re: Report Hisses at VOIP Quality Stephen,
thank you for replying but i think there's been a misunderstanding. I wasn't asking why incumbents or traditional SP do not use skype codec. This is something I know and that has to do with their legacy network in place for years now. I'm talking about the new VOIP providers. It reads in the article that among ten or so just a couple have an acceptable sound quality. So why don't they all switch to a skype-like codec? Sound quality issues would be minimized (at least).
stephencooke 12/5/2012 | 4:07:53 AM
re: Report Hisses at VOIP Quality netsalesman,

"Why don't provider use the same codec as skype?"

Long story, but suffice it to say that it has been standardized worldwide for decades and it is in every digital piece of access gear. It was designed back in the 1970's. Back then, 64kb/s was more than enough bandwidth to compete with 'scratchy' analogue equivalents. In today's CD quality expectations it falls short of the mark.

alchemy 12/5/2012 | 4:07:52 AM
re: Report Hisses at VOIP Quality netsalesman writes:
Liked the article a lot. Just a thing about sound quality: how come that skype quality is so high (much higher than POTS or PSTN which is indeed quite poor being just limited to a 8Khz spectrum) ? Why don't provider use the same codec as skype?

I thought Skype used the Global IP Sound iLBC codec? I have collected quite a bit of codec bake-off information including audio files fed through a half-dozen of the most popular compression codes. To my ear, iLBC is the worst codec. It's terrible reproducing things like music on hold and it does a poor job reproducing higher frequency female voice. Vanilla G.711 is superior to all the compression codecs. Of the compression codecs, I think G.729e does the best job with speech but even it sounds lousy with a typical music on hold.

For any audio testing I've ever done with "toll quality" codecs, the quality of the speaker and microphone on each end of the phone call ends up being far more important than the codec used.

Wideband codecs are useless at the moment since 99% of calls end up at the PSTN where you're stuck with the 3.1 khz limitations of G.711.
spelurker 12/5/2012 | 4:07:51 AM
re: Report Hisses at VOIP Quality > how come that skype quality is so high (much higher than POTS
> or PSTN which is indeed quite poor being just limited to a 8Khz
> spectrum) ? Why don't provider use the same codec as skype?

I have not found Skype's quality to be all that high, even when compared to POTS. But I doubt the codec plays a big role in either skype or anyone else's day-to-day quality. I blame the fact that the VoIP apps and the networks don't play well together. And, as alchemy points out, microphone quality plays a big role too.

I agree with (unlimited?) that VoIP is at a disadvantage without a decent market differentiator. Price seems to be the only one so far. I'm not well tuned-in to the enterprise market anymore, but I could see VoIP being a big deal there, since the converged network will give lots of $$$ savings. (plus email accessible voicemail & other fun toys)
mrbhagav 12/5/2012 | 4:07:51 AM
re: Report Hisses at VOIP Quality
Check out NodeLogic, NetLogic and their competitors. There is renewed interest in Layer 7 control of IP streams to enhance QoS of VoIP and converged services.

I would be interested in understanding what this forum thinks about the technical and commercial potential of specialized VoIP/IPTV technologies.

Mark Sullivan 12/5/2012 | 4:07:46 AM
re: Report Hisses at VOIP Quality The codec isn't the problem with Skype. It's the worst and most annoying problem of all -- delay. Correct me if I'm wrong, but this problem still plagues Skype service. It's a problem with cell phone service too, but is ignored because of the convenience factor.
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