Muni fiber: L1 or L2?

Tue Feb 5 01:05:23 UTC 2013

>> That's where we disagree. The benefit is that:
>>
>> 1. It doesn't lock the entire area into a single current technology.
>>
> Neither does a ring architecture.
>
>
>
> Yes it does... It locks you into whatever is supported on the ring.
>

I don't know how I can explain this more plainly, I can (more accurately
have) taken a fiber build that was created as a ring & spoke SONET system
and with the same fiber plant overlaid that with GigE and ATM (further back
in time) to backhaul for PON, DSL, VOIP, and direct Active Ethernet.  There
is nothing about a hub & spoke architecture is this harmful or even
suboptimal for doing Gig-E directly to end users today.  This wasn't always
true because we've only had 40G and 100G Ethernet for carrier networks for
a few years.  In the past we were limited by how big of an etherchannel
network we could use for the ring.  I'd also point out that the
ring architecture is optimal for redundancy since you have fewer fiber
bundles to get cut in the field and any cut to your ring gets routed around
the ring by ERPS (http://en.wikipedia.org/wiki/ERPS) in less than 50
milliseconds.

>
>  2. It allows for individual subscribers (probably mostly businesses, but
>> I have had a few occasions
>> where this would have been useful as an individual) to get dark XC to
>> other locations.
>>
> Neither does a ring architecture, you do have fewer long runs, but in any
> build you're going to end up with spare pairs to use for this and in my
> experience the number of businesses who want this in given area are very
> small.  I can't think of a network where this is more than 1% of the
> business connections.
>
>
> That's because today, it's expensive and the price is usually way way way
> above cost-recovery (or, it's cost
> recovery of the build cost / n where n is a very small number of fibers).
>
> Lower the price per instance and you very likely find new demands.
>

The vast majority of business don't WANT that kind of connectivity. How
many MPLS connections get purchased by SMBs?  That's the same kind of
connectivity at layer 3 and that's a market that is almost entirely used by
large corportations.

>
>
>
>> 3. Subscribers who want individualized services from different vendors
>> have a choice.
>>
>
> Subscribers don't care if the hand off is at layer 1 or layer 2 so this is
> moot as well.
>
>
> But the vendors do and it makes a huge difference to the barrier to entry
> price for competing
> vendors offering different services. (I'm talking about more than just IP
> at this point).
>

What vendors?  ISPs don't.

>
>
>
>>  4. Providers have to compete on a leveled playing field and there is
>> thus incentive to innovate
>>  even if the innovation moves away from PON.
>>
>
> Again, this is a completely moot point.  There is nothing in a ring or hub
> & spoke architecture that makes open access more difficult EXCEPT if you
> want to share lots of L1 connections.
>
>
> What I'm proposing is a hub and spoke architecture. It's just a much
> larger hub with much longer spokes.
>

That's called home running, but as I've said that's ok in some scenarios,
its just that in most cases there is no benefit.

>
>
>
>
>>
>>
>>
>>>
>>>
>>>
>>>>
>>>> I'm not sure why you think it would be hard to delineate the
>>>> responsibilities… You've got a fiber path maintained by the municipality
>>>> with active equipment maintained by the ISP at each end. If the light
>>>> coming out of the equipment at one end doesn't come out of the fiber at the
>>>> other end, you have a problem in the municipality's domain. If the light
>>>> makes it through in tact, you have a problem in the ISP's domain.
>>>>
>>>> There is equipment available that can test that fairly easily.
>>>>
>>>
>>> OK, this one made my wife get scared I laughed so hard.  You clearly
>>> have never tried to do this or had to work with different operators in the
>>> same physical network.  Please, go talk to someone whose worked in the
>>> field of a FTTx network and describe this scenario to them.  Its clear you
>>> don't want to hear it from me via email so please go do some research.
>>>
>>>
>>>
>>> I've talked to a few people doing exactly that. Yes, you need different
>>> test sets depending on which L2 gear is involved, but, in virtually ever
>>> case, there is a piece of test gear that can be used to test a loop
>>> independent of the configuration of the L2 gear in question.
>>>
>>
>> Yes, there is a meter for all the different kinds of technologies that
>> you might want to support.  For example a DOCSIS 3.0 DSAM from JDSU will
>> run you around $8000.00  A PON meter with long range lasers (more than 10
>> miles) from JDSU or Trilithic will cost you nearly $10,000.  Exactly how
>> many of those kinds of meters do you want to have to buy?  How many of your
>> staff are you going to train on them (they do require training and
>> knowledge to  use)?
>>
>>
>> For my proposed methods of build-out, no need for the long range lasers.
>> As I said, everything should be within 8km of the MMR.
>>
>> As I suggested, the simpler approach is to require the complaining L2
>> provider to cooperate in the diagnostic process and provide access to the
>> applicable meters if necessary. The standard offered absent assistance from
>> the L2 provider is OTDR success.
>>
>
> Medium range lasers (anything that's running on single mode fiber) versus
> long range don't drive the cost.  OTDR is not and cannot test for any phase
> modulated system and that includes every form of PON, Active Ethernet, and
> RFoG.  You _might_ be able to use one to test RS-232 over fiber depending
> on the vendor.  This is where you're really not getting it.  As the owner
> of the physical medium you WILL be the blame of every problem until you
> prove differently.  Every end user install that goes poorly, every
> time there is a connection drop, and every time some end user of $L1
> partner calls them complaining the city will get the blame.
>
>
> You're assuming the current business model of incumbent-provider owned
> fiber. In a case where you have service providers not allowed to own fiber
> and a fiber provider not allowed to provide services, the incentives all
> work towards cooperation and the conflicts of interest between them are
> eliminated. I understand what you're saying about field technicians and
> their motivations, but, again those are based largely on the current
> business models and compensation schemes. In the proposed arena, there's no
> reason management at the service provider and management at the fiber
> provider cannot work together to address these issues. Further, the
> technician that blames the fiber plant for everything rather than
> cooperating to resolve said issues together will inherently have his
> installations take longer than the ones that cooperate, so he is actually
> already automatically incentivized in the correct direction. Admittedly,
> without some education, that may not be intuitively obvious to him, but I
> find that education is usually possible when attempted.
>

You need to understand that I've built the exact network your describing
several times and in all those case this was for a muni network in a
relatively small town (<25,000 residents).  I also know who the installers
are in that sized community (as a group, not personally) and even if you
get the best ISP partners on the planet they're going to have normal
installers doing much of the work.

>
> For providers getting L1 service, it wouldn't be too hard to make this
>>> testing /  providing necessary test equipment part of their contract.
>>>
>>> The long and short of it is lots of people have tried to L1 sharing and
>>>> its not economical and nothing I've seen here or elsewhere changes that.
>>>>  The thing you have to remember is that muni networks have to be cost
>>>> effective and that's not just the capital costs.  The operational cost in
>>>> the long term is much greater than the cost of initial gear and fiber
>>>> install.
>>>>
>>>> We can agree to disagree. A muni network needs to be able to recover
>>>> its costs. The costs of building out and maintaining home-run
>>>> fiber are not necessarily that much greater than the costs of building
>>>> out and maintaining fiber at the neighborhood. One option, for
>>>> example, would be to have neighborhood B-Boxes where the fiber can
>>>> either be fed into provider-specific splitters (same economy
>>>> as existing PON deployments) or cross-connected to fiber on the F1
>>>> cable going back to the MMR (home-run).
>>>>
>>>>
>>> We can agree all we want, that doesn't change history.  Handing out
>>> connections at layer 1 is both more expensive and less efficient.  Its also
>>> extremely wasteful (which is why its more expensive) since your lowest unit
>>> you can sell is a fiber strand whether the end customer wants a 3 mbps
>>> connection or a gig its the same to the city.  I'm not saying you shouldn't
>>> sell dark fiber, I'm saying that in 99% of the cities you can't build a
>>> business model around doing just that unless your city doesn't want to
>>> break even on the build and maintenance.
>>>
>>>
>>> If it's $700 per home passed to build out home-run fibers (which seems
>>> to be a reasonable approximation from earlier discussions), then there's no
>>> reason you can't sell $40/month service over that where the L1 component is
>>> a $10/month ($7 for capital recovery, $3 for operations and support)
>>> pricing component.
>>>
>>
>> Nope, no reason at all if you don't care about covering your costs.
>>
>>
>> I just explained where the expected costs get covered, so you're going to
>> have to explain that statement.
>>
>
> No, you listed some more than optimistic numbers and passed that off as
> evidence.  If you seriously think that the fiber connection is only worth
> $10 per month then you're off by ~100%.
>
>
> Even if it's $20/month and you charge $50/month for L3 service and you're
> still in good shape. However, the real world numbers presented so far show
> costs closer to $10/month, so I'm not sure where your data is coming from.
>

This is about what it costs to provide physical layer connectivity with
most wired technologies in rural and smaller suburban environments.
 (Interestingly it actually costs more for wireless networks, though that's
specifically not "cellular" but rather fixed and nomadic BWA like WIMAX.)

>
>
>
> However, the point is that building the infrastructure in that manner
>>> doesn't cost much more than building out traditional PON infrastructure (if
>>> you're doing it from greenfield) and it can support either technology.
>>>
>>
>> Sure it does, even in greenfield and whats more it costs more over the
>> long term UNLESS you know where every home and business will be located 10
>> years from now.
>>
>>
>> More yes, much more, I'm not so convinced.
>>
>
> You think the fiber connectivity is only worth $10 too....
>
>
> $20/subscriber/month still strikes me as being within the realm of "not
> much more". So, based on your statement above...
>

Build your economic model, that delta of $10 is a big deal when you look at
thousands of connections.

>
> Owen
>
>
>
>

-- 
Scott Helms
Vice President of Technology
ZCorum
(678) 507-5000
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http://twitter.com/kscotthelms
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