Muni fiber: L1 or L2?

Jay Ashworth jra at
Thu Jan 31 01:27:27 UTC 2013

----- Original Message -----
> From: "Leo Bicknell" <bicknell at>

> In a message written on Tue, Jan 29, 2013 at 07:11:56PM -0800, Owen
> DeLong wrote:
> > I believe they should be allowed to optionally provide L2 enabled
> > services of various
> > forms.
> Could you expand on why you think this is necessary? I know you've
> given this some thought, and I'd like to understand.

I'll give you my answer, which may not be the same as Owen's.

> The way I see it, for $100 in equipment (2x$50 optics) anyone can
> light 1Gbps over the fiber. The only way the muni has significantly
> cheaper port costs than a provider with a switch and a port per
> customer is to do something like GPON which allows one port to
> service a number of customers, but obviously imposes a huge set of
> limitions (bandwiths, protocols you can run over it, etc).

You're assuming there, I think, that residential customers will have
mini-GBIC ports on their routers, which has not been my experience.  :-)

Understand that I'm not concerned with minimizing the build cost to the
muni; I'm interested in *maximizing the utility of the build*, both to the 
end-user customers, *and* to local businesses who might/will serve them.

If all that potential small ISP has to bring me is a 10GE, *backhauled 
over one of my own pairs from whatever space they rent*, and *I'm* 
responsible for all the muxing, the part of the Public Good which 
tries to bring businesses to the city is well served by that.

> I also think the "ONT" adds unnecesary cost. They are used today
> primarily for a handoff test point, and to protect shared networks
> (like GPON) from a bad actor. With a dedicated fiber pair per
> customer I think they are unnecessary. I can see a future where
> the home gateway at the local big box has an SFP port (or even fixed
> 1000baseLX optics) and plugs directly into the fiber pair.

This depends on exactly how the ONT is built, and I am not as familiar
with the field as I will be by the time I have to care.  But the ability
to deliver multiple VLANs over a single pair, and possibly terminate
all 3 pairs in one ONT (or in several, for redundancy), and the handoff 
is Ethernet -- and possibly DOCSIS3.0 RF, depending on what the boxes
already come with (I'm not interested in custom hardware at my scale) -- is quite fetching to me for all those reasons.

> No ONT cost, no ONT limitations, no need to power it (UPS battery
> replacement, etc). It's a value subtract, not a value add.

Based also on the point Owen makes about reducing truck rolls by having
netadmin controlled hardware at the customer end, I'm not at all sure
I agree; I think it depends a lot on what you're trading it off *against*.

I am, I admit, not all that fond of distributed power, but you make the
trades you must.

-- jra
Jay R. Ashworth                  Baylink                       jra at
Designer                     The Things I Think                       RFC 2100
Ashworth & Associates         2000 Land Rover DII
St Petersburg FL USA               #natog                      +1 727 647 1274

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