[160273] in North American Network Operators' Group
Re: Muni network ownership and the Fourth
daemon@ATHENA.MIT.EDU (Jay Ashworth)
Sun Feb 3 09:35:10 2013
Date: Sun, 3 Feb 2013 09:34:58 -0500 (EST)
From: Jay Ashworth <jra@baylink.com>
To: NANOG <nanog@nanog.org>
In-Reply-To: <86pq0hblil.fsf@seastrom.com>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
----- Original Message -----
> From: "Robert E. Seastrom" <rs@seastrom.com>
> Data point, which makes the rest of this discussion moot:
>
> Since telcos are historically myopic and don't build (much) extra
> fiber into their plant to support future technologies, the only use
> for existing fiber in the ground in passive optical applications is to
> connect the COs. There is not enough running out towards the
> customers to support retrofitting it for PON.
It doesn't make it moot for me; I'm greenfield.
> Some more data that may inform your conceptualization - Split ratios
> of 128 and 64 only work in the lab. Proper engineering (overlap of dB
> and bits/sec/customer) will dictate split ratios of 16 or 32
> (depending on modulation scheme, and no, going to 10gbit modulation
> doesn't help; you still have the link budget problem) last time I did
> the math.
Yeah, I sorta figured this.
> Still, the power budget improvements by not going with a single strand
> active ethernet solution (which were another suggested technology and
> has actually been deployed by some muni PON folks like Clarkesville,
> TN) are huge. Imagine a 24 port switch that draws 100 watts. OK,
> that's 4w per customer. 30k customers from a served location, that's
> 120kw ($13k power bill if you had 100% efficient UPSes and 0 cost
> cooling, neither of which is true) just for the edge, not counting any
> aggregation devices or northbound switch gear.
Hmm. the optics don't have auto power control?
> Back at NN, we discounted this as a technology almost immediately
> based on energy efficiency alone.
>
> Anyway, in summary, for PON deployments the part that matters *is* a
> greenfield deployment and if the fiber plant is planned and scaled
> accordingly the cost differential is noise.
I assume you mean "the cost diff between GPON plant and home-run plant";
that's the answer I was hoping for.
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
