What vexes VoIP users?

Scott Helms khelms at ispalliance.net
Mon Feb 28 23:05:13 UTC 2011


> So then let's argue that ILEC-delivered POTS is digital too, because it went
> on fiber to the local SLC hut...
It is, at least in some cases, and its even VOIP in a few (Occam BLC's 
for example).  Having said that its almost never derived voice of any 
type into the home because of life line requirements.

> So's your handset.

That was kind of the point :)

> So let's look for a rational comparison instead.
>
> Take your CD player's analog audio output and run it fifty feet,
> making sure to route it along some nice fluorescent lights.  Even
> with a good shielded cable, analog signal is notorious for picking
> up noise.
>
> Now take your CD player's TOSLINK output and run it that same
> fifty feet.  I'm aware of the spec limits, but most modern gear
> with good cables will do this without a problem - we're discussing
> the difference between analog and digital here in any case.
>
> Anyways, listen to both and then let's talk about the difference
> that carrying a signal in an analog format needlessly can make.
>

You're working under the incorrect assumption that a user can't simply 
plug into the back of their EMTA and I assure that isn't the case.  An 
operator can choose to not use the in home wiring, and in some installs 
this is the right method,  but in the case of decent wiring and existing 
analog sets the user is happy with there's no reason to do so.

>> You can plug any ATA into the
>> existing home wiring, including the ones that Vonage deploys:
>>
>> http://support.vonage.com/doc/en_us/649.xml
> So here's the *point*:  if you have digital phones, maybe VoIP but could
> also certainly be any of the proprietary digital systems, why should you
> have to run through the ambiguity of a digital-to-analog-to-digital
> conversion?
I hate to tell you, but residential users don't to buy a new phone.  
They don't see any problem with their existing analog set and usually 
they're right.  We've been dealing with analog to digital conversions, 
at least one and sometimes two, in the local LEC system for decades 
without impacting MOS.  (It wasn't until GR-303 and TR-08 interfaces 
became common on switches that remote terminals got the signal digitally.)
> With end-to-end digital, you can have reliable call supervision and
> status, OOB Caller-ID delivery, crystal clear call quality, probably
> the ability to handle multiple calls intelligently, no hook race
> conditions, etc.
>
> When you throw that one stupid and pointless analog hop in there, you
> are suddenly limited and broken in so many ways.
>
> ... JG
What's broken for a residential user?  For that matter I'd rather get 
rid of every digital phone in our business, they're a waste of money, 
and run pure soft phones but until people start caring about voice (they 
don't, check cell MOS scores) and adopt wideband voice in numbers there 
is 0 reason for a home user to change.

-- 
Scott Helms
Vice President of Technology
ISP Alliance, Inc. DBA ZCorum
(678) 507-5000
--------------------------------
http://twitter.com/kscotthelms
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