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Summary:

I am getting sick and tired of this whole debate about how good VoIP should be? Just because we accept poor quality from cellphones, and PCs, we are supposed to expect poor quality or what some call, good enough quality in VoIP as well. Not so […]

I am getting sick and tired of this whole debate about how good VoIP should be? Just because we accept poor quality from cellphones, and PCs, we are supposed to expect poor quality or what some call, good enough quality in VoIP as well. Not so – first, there is the whole notion of cellphones. From day one, the consumer experience was terrible and any improvement in the networks comes as a pleasant surprise for us. So good enough here is actually better than what it was even a year ago. Similarly Windows XP is so much better than Windows 3.0. So we put up with mediocrity. Phone service on the other hand is working well, and our expectations are very high from it. Larry Borsato points out

To put this into perspective, 99.999% reliability means that phone service may potentially be unavailable for 5.3 minutes over the course of a year. By comparison, 98% reliability sounds reasonable, but actually the service could be unavailable for more than 7 days. Could you live without phone service for hours or days at a time? Probably not. The internet as it currently exists does not provide carrier-grade reliability, and by extension neither does VoIP. This really limits its use to early adopters. I can’t see the average person as willing to take this risk.

So if VoIP has to catch our imagination and remove PSTN from our thinking, well do a damn fine job, or else take a hike!

  1. There’s an excellent paper on availability and reliability of VoIP that I recommend: Assessment of VoIP Service Availability in the
    Current Internet

    Its conclusion is:
    Overall, we observe that the call success
    probability at around 0.5% and call abortion probability
    at about 1.5%, resulting in a 98% net availability, which is still
    some steps away from what the PSTN offers today (three to
    four 9’s), but already comparable to the availability of mobile
    telephone networks (around 97% to 99%).

    My take is that users only accept poorer quality if it is (more than) offset by a compelling feature. Example: mobile quality is worse than fixed line but that is the price to pay for mobility.
    What is the deal for VoIP?

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  2. Instead of drinking the cool-aid of PSTN replacement and PSTN interconnect, if we consider IP Communication where by two (or more) individuals communicate via text, speech, image and screen sharing etc., then the paradigm changes. The user may be willing to live with less reliability because the new mode of communication allows different form and experience. (Just like people agree to live with lower quality of cell phones.) The tragic flaw is in trying to replace (that means we have to replicate) PSTN. The irony is that VoIP proponents think PSTN is dead, but they keep PSTN in their radar all the time.

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  3. the question is not that we should have wireless back-up, but instead if we want VoIP to quack like PSTN, well then it has to be as good as PSTN. sorry but don’t buy the argument of having back-ups. Maybe IP should instead by integrated communication on IP

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  4. 99.999% Availability, Part Deux

    Since I saw Larry Borsato mention some figures in the 99.999% availability requirement-for-VoIP-networks debate, I decided it was time for me to dust off my networking theory book and implement Erlang formula on an Excel spreadsheet using VBA, to get a…

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  5. Hi Om, I posted my replies to the topic, and do not think our views are that far off.

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