Muni fiber: L1 or L2?

Leo Bicknell bicknell at
Thu Jan 31 02:52:17 UTC 2013

In a message written on Wed, Jan 30, 2013 at 08:27:27PM -0500, Jay Ashworth wrote:
> You're assuming there, I think, that residential customers will have
> mini-GBIC ports on their routers, which has not been my experience.  :-)

They don't today because there is no demand for such a feature.  My
point is that if people deployed FTTH in this way, there would be demand
for such products.  Many of the chipsets inside these boxes already
support SFP PHY, they just don't put an SFP connector on them to save a
couple of bucks.  If there was demand vendors would have a product out
in months not years, probably within $10 of current prices (not counting

> 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.

Yes, which is why you want to remove anything electronic possible,
and to large extent any prismatic devices.  Single mode from the
1990's will carry 10GE today, if unfettered.  Today's single mode
will carry 100GE+ for a 50+ year lifespan, if properly installed.
Electronics last 5-10, and then must be replaced, at a cost passed
on to consumers.  The GigE GPON isn't cutting it anymore?  Fine,
let's replace all the electronics and update the splitters to 10GE,
at great cost!

By having a direct fiber pair to the home ISP's could run 100Mbps to one
customer, GigE to another customer, and 10x10GE WDM to a third customer,
just for the cost of equipment.  Own two business locations?  You don't
even contract with an ISP; you pay the Muni $10/month for fiber to each
prem, and $2/month for a cross connect and light it up however you want.
Plug in a GigE LAN switch on each end and off you go.  It's the ultimte
empowerment, fiber for everyone!

> 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*.

That can be fixed in other ways.  It would be easy to make a standard
SNMP mib or something that the service provider could poll from the
customer gateway, and service providers could require compatable
equipment.  There are ethernet OAM specs.

When I get a Cisco router with an integrated CSU and the telco sends a
loop-up my device does it.  No reason the same can't be done with
ethernet, other than no demand today.

In a message written on Wed, Jan 30, 2013 at 09:24:51PM -0500, Jay Ashworth wrote:
> > To put that in patch panel racks, 10,368 households * 6 fibers per
> > house (3 pair) / 864 per rack = 72 racks of patch panels. Using a
> > relatively generous for 2-post patch panels 20sq feet per rack it
> > would be 1,440 sq feet of colo space to house all of the patch
> > panels to homes.
> Oh, I hope to ghod we can get higher density that that.

I'm sure it's possible.  I would be there is an LC solution by now, and
this is also discounting direct fusion splicing which would be 20-40x
smaller in footprint.

That said, the fiber MMR I'm proposing is of similar size to the telco
CO's serving the same size towns today; except of course the Telco CO is
filled with expensive switches, generators, battery banks, etc.

I don't want to understate the fiber management problem in the MMR, it's
real.  Some thought and intelligence would have to go into the design of
how patches are made, making heavy use of fusion splice trays rather
than connectors, high density panels, and so on.  That said, Telcos did
a fine job of this with copper for hundreds of years when every line ran
back to a central frame.  There are fiber providers doing similar things
today, not quite on the same scale but in ways that could easily scale

I would like to build an infrastrucutre that could last 50-100 years,
like the telephone twisted pair of the last century.  The only tech I
can see that can do that is home run single mode fiber to the home.
Anything with electronics has no chance of that lifespan.  Anything with
splitters and such will be problematic down the road.  Simpler is

       Leo Bicknell - bicknell at - CCIE 3440
        PGP keys at
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