Study: VoIP Quality Getting Worse. Can We Prioritize Now?

by on July 27, 2006 · 12 comments

Don’t look now, but your VoIP service may be getting worse. According to a report released this week by Brix Networks, an Internet monitoring firm, VoIP quality measurably declined in the past 18 months. Specifically, it found that 20 percent of VoIP calls had “unacceptable” quality, as opposed to 15 percent a year and a half ago. (The data was gathered from testyourvoip.com, a web site operated by Brix).

The chief tech offier of Brix, Kaydam Heydarat, says the decline is the result of VoIP having to compete for resources on an increasingly crowded web. If that sounds familar, it should–opponents of mandated net neutrality have long argued that congestion could hurt time-sensitive applications such as VoIP if network owners aren’t allowed to prioritize traffic. As Mr. Heydarat says: 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.”

To be fair, many–perhaps most–supporters of neutrality regulation now support prioritization (though it may be hard to reconcile with rhetoric condemning a “two-tier” Internet). They draw the line as charging money for priority service. It’s nevertheless hard to imagine how such a free prioritization system would work. Certainly, providers transmitting signals for non-priority services would rightly complain about being paying the same amount for slower service. And who would decide what services would qualify for prioirity service? The government? Far better to allow markets–and prices–to decide such things, as they do almost everywhere else in the economy.

Still, the Brix study should help quash any arguments that prioritization is not needed at all. It is– the current first-come-first-served is no longer adequate. Despite the congestion, that message should come through loud and clear.

  • http://www.techdirt.com/ Mike Masnick

    James, again I’m disappointed in you. You seem to have a tremendous blindspot whenever someone supports the position you’ve staked out. You throw all skepticism out the window.

    The Brix study is completely bogus. There’s no actual data to support the reason Heydarat claims. There are plenty of other reasons why they may have found quality declining — such as the fact that their TestYourVoip service may simply have gotten a lot more attention in places that people who are having trouble with their voip know about.

    As others have pointed out, this same study could just as easily be interpreted to mean that telcos could be degrading the quality of VoIP traffic — so perhaps the answer is that we should enforce net neutrality to stop telcos from degrading VoIP traffic.

    Basically, there’s nothing in this report that actually supports the fact that it’s additional network congestion that’s the problem. So, to interpret that way is just as ridiculous as to interpret it the way I do in the paragraph above.

    I’m not in favor of net neutrality regulations, but you’re making yourself look bad when you buy into these bogus claims over and over again.

  • http://abstractfactory.blogspot.com/ Cog

    And then there’s the fact that increasing bandwidth could work as well as (or maybe better than) packet prioritization. I’m reasonably certain that South Korean ISPs don’t do aggressive packet prioritization, but South Koreans’ VOIP works pretty well, because their connections are orders of magnitude faster than the USA’s. Overprovisioning is a pretty good engineering solution to scarcity.

    Ed Felten covered this a long time ago, and repeated it in his summary white paper. The response of the anti-neutrality pundits seems to be to pretend that this argument doesn’t exist.

  • http://www.techdirt.com/ Mike Masnick

    James, again I’m disappointed in you. You seem to have a tremendous blindspot whenever someone supports the position you’ve staked out. You throw all skepticism out the window.

    The Brix study is completely bogus. There’s no actual data to support the reason Heydarat claims. There are plenty of other reasons why they may have found quality declining — such as the fact that their TestYourVoip service may simply have gotten a lot more attention in places that people who are having trouble with their voip know about.

    As others have pointed out, this same study could just as easily be interpreted to mean that telcos could be degrading the quality of VoIP traffic — so perhaps the answer is that we should enforce net neutrality to stop telcos from degrading VoIP traffic.

    Basically, there’s nothing in this report that actually supports the fact that it’s additional network congestion that’s the problem. So, to interpret that way is just as ridiculous as to interpret it the way I do in the paragraph above.

    I’m not in favor of net neutrality regulations, but you’re making yourself look bad when you buy into these bogus claims over and over again.

  • http://abstractfactory.blogspot.com/ Cog

    And then there’s the fact that increasing bandwidth could work as well as (or maybe better than) packet prioritization. I’m reasonably certain that South Korean ISPs don’t do aggressive packet prioritization, but South Koreans’ VOIP works pretty well, because their connections are orders of magnitude faster than the USA’s. Overprovisioning is a pretty good engineering solution to scarcity.

    Ed Felten covered this a long time ago, and repeated it in his summary white paper. The response of the anti-neutrality pundits seems to be to pretend that this argument doesn’t exist.

  • http://www.brixnet.com Kaynam Hedayat

    James,

    Thank you for the posting. I would like to point out the following facts about the data:

    - Based on comments from the testyourvoip user community more than half the tests were run for pre-qualification purposes (prior to signing up for VoIP). In those cases the users did not know if they had problems or not prior to running the tests.
    - Close to one million tests were conducted for this study.
    - The types of impairments and degradation factors that we analyzed point to network congestion. We are further analyzing the data to understand the location of congestion (core, last mile, etc.).
    - Via the testyourvoip portal we measured and continue to measure “end-to-end” VoIP quality on the internet.
    - The tests are conducted between the user’s desktop to one of seven locations across the globe as selected by the user. The seven locations are connected to the internet via high BW connections without any impairments (they are monitored).

    I encourage you to take a look at the site (www.testyourvoip.com), run the test, and examine the data.

    Finally Brix Networks does not take any position in the Net Neutrality debate. The study simply points out that regardless of Net Neutrality or not successful VoIP deployments require end-to-end QoS.

    Regards,
    Kaynam Hedayat
    CTO, VP Eng
    Brix Networks

  • http://www.brixnet.com Kaynam Hedayat

    James,

    Thank you for the posting. I would like to point out the following facts about the data:

    - Based on comments from the testyourvoip user community more than half the tests were run for pre-qualification purposes (prior to signing up for VoIP). In those cases the users did not know if they had problems or not prior to running the tests.
    - Close to one million tests were conducted for this study.
    - The types of impairments and degradation factors that we analyzed point to network congestion. We are further analyzing the data to understand the location of congestion (core, last mile, etc.).
    - Via the testyourvoip portal we measured and continue to measure “end-to-end” VoIP quality on the internet.
    - The tests are conducted between the user’s desktop to one of seven locations across the globe as selected by the user. The seven locations are connected to the internet via high BW connections without any impairments (they are monitored).

    I encourage you to take a look at the site (http://www.testyourvoip.com), run the test, and examine the data.

    Finally Brix Networks does not take any position in the Net Neutrality debate. The study simply points out that regardless of Net Neutrality or not successful VoIP deployments require end-to-end QoS.

    Regards,
    Kaynam Hedayat
    CTO, VP Eng
    Brix Networks

  • http://bennett.com/blog Richard Bennett

    Note that Mike Masnick’s comment is full of bluster and stops short of offering any verifiable facts.

    And as to the argument that “over-provisioning solves the QoS problem”, there are a couple of key points that those who make this argument always overlook: 1) over-provisioning isn’t cheap, and in many situations is actually prohibitively expensive or not possible due to physical constraints (such as wireless bandwidth); and 2) QoS isn’t a solution to persistent bandwidth scarcity, it’s a solution to the effects that bursty traffic (such as file downloads) have on streams with modest bandwidth requirements but tight jitter requirements. Regardless of your bandwidth, the billion users of the Internet can fill any segment to overflowing. The more bandwidth you bring to my house, the more traffic I can generate on the internal links. Bandwidth goes both ways, so increasing it simply moves the bottlenecks around, it doesn’t eliminate them.

    To mix bandwidth and jitter is to confuse the two key terms of network design.

  • http://bennett.com/blog Richard Bennett

    Note that Mike Masnick’s comment is full of bluster and stops short of offering any verifiable facts.

    And as to the argument that “over-provisioning solves the QoS problem”, there are a couple of key points that those who make this argument always overlook: 1) over-provisioning isn’t cheap, and in many situations is actually prohibitively expensive or not possible due to physical constraints (such as wireless bandwidth); and 2) QoS isn’t a solution to persistent bandwidth scarcity, it’s a solution to the effects that bursty traffic (such as file downloads) have on streams with modest bandwidth requirements but tight jitter requirements. Regardless of your bandwidth, the billion users of the Internet can fill any segment to overflowing. The more bandwidth you bring to my house, the more traffic I can generate on the internal links. Bandwidth goes both ways, so increasing it simply moves the bottlenecks around, it doesn’t eliminate them.

    To mix bandwidth and jitter is to confuse the two key terms of network design.

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