Sent from my iPhone On Mar 1, 2011, at 8:35 PM, Jay Ashworth <j...@baylink.com> wrote:
> ----- Original Message ----- >> From: "Michael Thomas" <m...@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 >