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VoIP Quality, Getting Worse

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Brix Networks, a company that develops monitoring tools for VoIP says that the quality of VoIP calls is getting worse. The company maintains a website called,, and in a study published today the company said that nearly 20% of VoIP calls have unacceptable quality. That is up from 15% of all test calls a year ago.

I think the problem actually might be bigger. A lot of my friends who call me on Vonage for instance sound as if they are calling from a different planet. A lot of these problems are due to bandwidth constraints on the networks. Trying watching You Tube videos and talking over a VoIP phone and you experience the downshift in quality first hand. This alone should be a reason to a pipe with faster connection, and carriers could easily up sell premium services to their customers.

“The network is ready for VoIP. But now that there are more services running over the same pipe, carriers need to differentiate packets and prioritize service,” Kaynam Hedayat, chief technology officer for Brix tells C/Net (Okay that made me wonder who paid for the service!) It is not just the VoIP calls to the consumer home which are sounding bad. If you have ever made international long distance calls, you can experience the degraded quality first hand. Those calls, many of them originating from incumbent phone systems, also travel over an IP network.

17 Responses to “VoIP Quality, Getting Worse”


    I don’t seem to have this problem on my Cablevision network connection. The thing here is, that Voice service and Data are sent out across the same network equipment (I engineered for Qwest, 360networks, MCI, IXC, etc.) and all the traffic went from either a switch or router to SONET backbones, and back again. As a rule, the bottlenecks happen at the local loop (the all circuits are busy) is from your local provider (don’t care if you use an incumbent carrier, DSL, or CLEC) the local provider owns the network and routes the traffic. I would suggest that it is the incumbents…but I could be wrong.

  2. One of my favorite terms:
    Time-dependent. Pronounced eye-sock-ra-nuss, it refers to processes where data must be delivered within certain time constraints. For example, multimedia streams require an isochronous transport mechanism to ensure that data is delivered as fast as it is displayed and to ensure that the audio is synchronized with the video.

    In my simple minded understanding, the Internet is a best-effort datagram service that does not employ QoS end-to-end. Therefore, it is entirely possible that our lowly voice bandwidth gets jumbled as it cross the ‘net. It’s like trying to keep a marching band together as we navigate the subway system across Manhattan even though each band member only requires one seat.

    Tee Emm, take two valium and post in the morning.

  3. John Thacker

    Would be interesting to run VoIP tests with people that have TimeWarner VoIP or Verizon VoIP. Then we could see if its limited to pureplays or its wirespread to all VoIP carriers. Results of those studies could say a lot about the causes.

    Although it wouldn’t solve the “you’re degrading the call” versus the “you’re not using QoS support” debate. After all, Time Warner reserves bandwidth and uses proper QoS support in order to make sure that their Digital Phone service works properly. Of course, they say that they’d love to sell that QoS support to Vonage and other pure VoIP carriers, but Net Neutrality won’t let them…

    And so the debate will go on.

  4. Patrick Mullen

    In terms of quality of service, voice is a bit different. If you are downloading a song or a program, a bit of latency really doesn’t matter. Even though the bandwidth for voice isn’t all that big a requirement, the latency is really important, be on a call and have some packets delayed a bit, then you have a problem.

    Would be interesting to run VoIP tests with people that have TimeWarner VoIP or Verizon VoIP. Then we could see if its limited to pureplays or its wirespread to all VoIP carriers. Results of those studies could say a lot about the causes.

  5. For years I’ve been quite happy with the sound quality of Vonage, in fact it was far better than POTS. What I am experincing now is a problem when the call is between different VOIP services:

    Vonage to Lingo,
    Skype to US phone number when it’s VOIP …etc.

  6. Some problems are inherent in the network. You can’t overcome a cetain level of latency. However, Vonage and others who don’t use Global IP Sound are not maximizing their QoS. GIPS is a necessary component in any IP voice service.

  7. It’s the tubes!!!

    On a serious note, however, I thought your post was really interesting. I’ve wondered about my Skype connection recently because of increased difficulty in getting the same crystal-clear connections I was getting a year ago.

    A widespread problem perhaps?

  8. bluechihuahua

    that’s piece makes me giggle–it just sounds like ANOTHER rotten trickle for Vonage (VG). stock closed 6.92 last night–losing 59.3% off the $17 IPO issue, and that was 2 months ago. as for options, maybe the specialist will finally add the 2.5 level.

  9. While I recognise lack of clarity on Vonage very few times, I see no issue if I am talking on Skype. I guess then, some thing to do with Vonage than mere lack of bandwidth on the network or Skype is lot better than Vonage in transmitting voice at low bandwidth.

  10. Chris Seilern

    This is just too much fluff to just sit here and say nothing.

    Voice bandwidth is measured in kilobits per second. Almost all broadband upstream is measured in HUNDREDS of kilobits per second. There should be NO issue with voice quality. Period.

    Even taking on board max contention rates, the actual likelihood of voice quality degradation in a VOIP on broadband environment should be virtually 0.

    If there is degradation, it is because someone is protecting a legacy Voice revenue stream somewhere (read: traffic shaping, throttling).

    And for GigaOM to write about voice degradation as if it were a burden valiantly managed by the heroes who own the networks is a pure distortion. Network owners are there to make money, not to allow end users to run free VOIP apps, and GigaOM should be enough of a critic to know this and not to promote a Network centric view under the guise of independent opinion.

    This will all end badly and as much as network owners want to control what goes on their network, the genie is out of the bottle and end users will eventually run what they want. Don’t believe me? see
    to see what Bittorrent is doing to prevent throttling and traffic shaping.

  11. Tee Emm

    The irony of the situation is, that factually, VoIP is a low-bandwidth application.

    I would say it is the overall lack of QoS that is part of the IP/Internet world that makes VoIP break even on networks that are almost ten time as capacitative than what they used to be a few years ago.

    Thanks to p2p and general absence of applied IP Qos, every VoIP call will remain a blind date for most of us.

    Tariq Mustafa

  12. Do you think

    a) it’s a change in the quality of the service?

    b) that the pipes aren’t big enough? or . . .

    c) the Telecoms are purposefully degrading the quality of the call?

    I’m betting it’s probably C as they own the Internet Backbone. What’s your bet?