What vexes VoIP users?

Owen DeLong owen at delong.com
Tue Mar 1 01:48:18 CST 2011


On Feb 28, 2011, at 11:22 PM, Jeff Wheeler wrote:

> On Mon, Feb 28, 2011 at 6:28 PM, Leigh Porter
> <leigh.porter at ukbroadband.com> wrote:
>> Exactly the point I made earlier. POTS is simple, it does what it does and it is pretty good at it. Now, in the background, you have a whole lot of engineering. But I would trust a DMS100 far more than any of the stuff that routes IP.
>> 
>> POTS is cheap, easy, scalable and resistant to many disasters that would soon wipe any VoIP network out.
> 
> I wouldn't call DMS100 a "cheap" platform.  The switch gear is
> expensive, features are expensive, floor space is expensive, training
> is expensive, and provisioning, for the most part, is stuck in the
> dark ages.
> 
Per subscriber, amortized over the likely 20-30 year lifetime of a
DMS-100, compared to VOIP gear, rapid product life cycling, and
low subscriber density, uh, yeah, the DMS-100 is, actually cheap
in many cases.

> Sure, it works, but to make the generalization that it's cheaper than
> modern VoIP switching is just incorrect.  Besides that, if you have
> done much DMS100 ops, you are well aware that there are many
> (infrequent) tasks that require multi-hour outages of major DMS100
> components, e.g. one of the two CMs (control plane, for unfamiliar
> readers.)  In addition, the official maintenance procedures often
> don't tell you how to perform these tasks without taking the whole
> switch out of service.
> 
VOIP is just starting to get cheaper than POTS, but, barely.

As to the reliability issue, you're technically correct, but, there is
actually a very strong emotional connection for many end users
of "I want my phone to work to call 911 when the lights are out."

Cellular, in spite of its reliability issues is perceived to provide that.
POTS is perceived to provide that and it's pretty rock solid.
VOIP is perceived to have that as a severe limitation.

Owen





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