What vexes VoIP users?

Wed Mar 2 03:42:29 UTC 2011

Sent from my iPhone

On Mar 1, 2011, at 8:35 PM, Jay Ashworth <jra at baylink.com> wrote:

> ----- Original Message -----
>> From: "Michael Thomas" <mike at mtcc.com>
>
>> On 03/01/2011 05:51 AM, Jay Ashworth wrote:
>>> Let us be clear: if you're getting "digital telephone" service from a
>>> cable television provider, it is *not* "VoIP", in the usage in which
>>> most speakers mean that term -- "Voice Over Internet" is what they
>>> should be saying, and cable-phone isn't that; the voice traffic rides over
>>> a separate DOCSiS channel, protected from both the Internet and CATV
>>> traffic on the link.
>>>
>>
>> Er, I'm not sure what the difference you're trying to make.
>
> Er, I'm not sure why...
>
>> Is IP running over an L2 with a SLA any less "IP" than one
>> without a SLA? That's all the DOCSIS qos is: dynamically
>> creating/tearing down enhanced L2 qos channels for rtp
>> to run over. It's been quite a while since I've been involved,
>> but what we were working on with CableLabs certainly was
>> VoIP in every respect I can think of.
>
> Wow.
>
> I thought I was pretty clear in what I said above; I'm sorry you didn't
> get it.
>
> "What everyone is actually *selling* commercially, except for cable
> providers, is *not* VoIP; it's a subset of that: VoN; Voice Over Internet;
> where the IP transport *goes over the public internet*, and through
> whatever exchange points may be necessary to get from you to the
> provider.
>
> Cable companies are selling you *one hop* (maybe 2 or 3; certainly not
> 12-18), over a link with bandwidth protected from whatever may be
> going on on the Internet IP link they're also selling you; and which is
> therefore guaranteed to have better quality than whatever "VoIP" service
> it might be competing with."
>
> Better?
>

Many VoIP companies like jive, peer with providers to give customers
"*one hop* (maybe 2 or 3; certainly not
>
> 12-18), over a link with bandwidth protected from whatever may be
> going on on the Internet IP link they're also selling you;"
VoN? Didn't know there was a difference. Same protocols, same
RTP,RTCP, Codecs, DSCP values. Am I missing something?

>> | As I recall, this questionably fair competitive advantage has been
>>> looked into by ... someone. (Cablecos won't permit competing VoIP
>>> services to utilize this protected channel, somewhere between
>>> "generally"
>>> and "ever".)
>>
>> There's is a great deal of overhead involved with the booking
>> of resources for enhanced qos -- one big problem is that it
>> adds quite a bit of latency to call set up. I'm sceptical at this
>> point that it makes much difference for voice quality since voice
>> traffic is such a tiny proportion of traffic in general -- a lot has
>> changed in the last 15 years. Now video... I'm willing to believe
>> that that enhanced qos still makes a difference there, but
>> with youtube, netflix, etc, etc the genie isn't getting back in
>> that bottle any time soon. So Moore's law is likely to have the
>> final word there too making all of the docsis qos stuff ultimately
>> irrelevant.
>
> I wasn't suggesting QOS.  I was suggesting *there's a completely separate
> pipe*, on non-Internet connected IP transport, carrying only the
> voice traffic, directly to a termination point, which is dedicated
> from the triple-play box and nailed up.
>
> Are you suggesting that's *not* how it's being done in production?
>
> Cheers,
> -- jra
>