Re: Fwd: Rollup: Small City Municipal Broadband

[Tim Jackson <jackson.tim () gmail com>]

Word to dropping docsis science on NANOG.
On Feb 2, 2013 3:34 PM, "Scott Helms" <khelms () zcorum com> wrote:

> > I hope I said "E7"; it's what I meant to say.  Yes, I wasn't going to
> > stop at Calix; I'm just juggling budgetary type numbers at the moment;
> > I'll have 3 or 4 quotes before I go to press.  It's a 36 month project
> > just to beginning of build, at this point, likely.
> >
> > Assuming I get the gig at all.
>
> The E7 is a good shelf, so that's a decent starting point.  I'd also talk
> with Zhone, Allied Telesys, Adtran, and Cisco if for no other reason but
> get the best pricing you can.  I'd also focus much more on your cost per
> port than the density since your uptake rate will be driven by economics
> long before port density and how much space your gear takes becomes an
> issue.
>
> > > 2) I have no idea who told you this, but this is completely and utterly
> > > incorrect in nationwide terms. If you have a specific layer 3 provder
> > > in mind that tells you they want a GPON hand off then that's fine, but
> > > ISPs in general don't know what GPON is and have no gear to terminate
> > that
> > > kind of connection.
> >
> > Other people here, said it.  If nothing else, it's certainly what the
> > largest nationwide FTTH provider is provisioning, and I suspect it serves
> > more passings than anything else; possibly than everything else.
>
> I'm not sure what you mean by this.  The largest PON offering in the US is
> Verizon's FIOS, but AFAIK they don't interconnect with anyone at layer 2
> and their layer 3 fiber connections are either Packet Over SONET, Gig
> E(most common), or very occasionally still ATM.  I have heard of a few
> instances where they'd buy existing GPON networks but I've never heard of
> them cross connecting like this even with operators that they do
> significant business with in other ways.
>
>
> > But it doesn't matter either way, except in cross-connects between my MDF
> > and my colo cages; except for GPONs apparent compatibility with RF CATV
> > delivery (which I gather, but have not researched) is just
> block-upconvert,
> > I don't care either way; there's no difference in the plant buildout.
>
> This is not correct.  DOCSIS is an MPEG stream over QAM or QPSK modulation
> and there is nothing about it that is compatible to any flavor of PON.  In
> fact if you look at the various CableLabs standards you'll see DPoE (
> http://www.cablelabs.com/dpoe/specifications/index.html) which lists how a
> DOCSIS system can inter-operate and provision an PON system. If you look at
> the two largest PON networks (FIOS and Uverse) you'll see the two different
> approaches to doing video with a PON architecture.  Verizon is simply
> modulating a MPEG stream (this is block compatible to a cable plant, in
> fact its the same way that a HFC network functions) on a different color on
> the same fiber that they send their PON signalling.  ATT takes another
> approach where they simply run IPTV over their PON network.  I've listened
> to presentations from Verizon's VP of Engineering (at that time) for FIOS
> and he said their choice was driven by the technology available when they
> launched and they did modulated RF over their fiber instead of IPTV because
> that technology wasn't as mature when they started. Verizon's approach may
> be what someone was thinking of when they said that PON was compatible to
> cable signaling but that's not how it works.
>
>
> > Cheers,
> > -- jra
> > --
> > Jay R. Ashworth                  Baylink
> > jra () baylink com
> > Designer                     The Things I Think                       RFC
> > 2100
> > Ashworth & Associates     http://baylink.pitas.com         2000 Land
> > Rover DII
> > St Petersburg FL USA               #natog                      +1 727 647
> > 1274
>
>
>
> --
> Scott Helms
> Vice President of Technology
> ZCorum
> (678) 507-5000
> --------------------------------
> http://twitter.com/kscotthelms
> --------------------------------
>
>
>
> --
> Scott Helms
> Vice President of Technology
> ZCorum
> (678) 507-5000
> --------------------------------
> http://twitter.com/kscotthelms
> --------------------------------