Muni fiber: L1 or L2?

Sun Feb 3 20:18:12 UTC 2013

> Keep in place, but I've worked with virtually all of the nationwide guys
> and most of the regional ones and they don't as a rule want anything to do
> with your fiber plant.  Even in major metro areas selling dark fiber
> doesn't have a huge uptake because if you the network owner didn't light it
> you have no idea how good or bad the splices and runs are.
> 

The willingness to cooperate and accept using someone else's fiber will
definitely be a gating issue here, but I bet there will be providers
that will be willing to do so.

>> 
>>>                To make matters more complicated in cases of problems
>>> you don't have a good demarcation of responsibility. What do you do as
>> the
>>> L1 provider when one of your ISP partners tells you one of his customers
>>> can't connect or stay connected to that ISP's gear? Whose responsible in
>>> that case?
>> 
>> Well that's an interesting question, but I don't see that it's not
>> orthogonal to the issue you raised earlier.
>> 
>>> What happens when your tech goes out with an OTDR (
>>> http://en.wikipedia.org/wiki/Optical_time-domain_reflectometer) meter
>>> and says the connection is fine but your ISP insists its your problem?
>> 
>> On an L1 connection, you mean?  I'll do what people always do; I'll work
>> the ticket; at that level, this stuff's relatively digital, no?
>> 
> 
> No, its not and I've seen several of networks fail because demarc issues.
> US Carrier (a statewide network here in GA) was recently sold for pennies
> on the dollar largely because of blurry demarcs. You can and will get
> sucked into scenarios you don't want to be in and will lose money on.

But there isn't a lot of blur to the demarc in this case. Further, since
we're talking about a muni doing this on a cost-recovery pricing basis,
sucking the muni into such scenarios will only increase the prices charged.
The muni won't lose money, the muni will just get more expensive.

As a general rule, if the providers know that cooperative debugging ==
resolution and uncooperative finger-pointing == increased costs, you
tend to get a lot more cooperative debugging.

>> 
>>>> You're talking about what I'm calling L2 clients. If layer 2 falls
>>>> over it's my fault, and believe me, I'll know about it.
>>> 
>>> What I'm telling you is that you can't reliably have L1 clients in
>>> shared model.
>> 
>> You're telling me that, but you're not giving me good reasons *why* you
>> think so.
>> 
> 
> Because:
> 1) There won't be much interest in doing it from experienced operators so
> you're only going to get customers for it that are also new to the
> business.  So your combined troubleshooting and install time will be bad
> for a long time until everyone in the chain kind of understand what they're
> doing.

Unless you can recruit some experienced providers up front and work with
them, allowing them to observe the build-out, etc. so that there is a
higher degree of confidence in the quality of the runs and splices.

Providing certified test results of the fiber runs can probably also help
here.

> 2)  Unless you can home run every single connection you're going to run
> into a lot of access related issues.  You will be working for the city so
> they won't have a problem with you getting into their building at the water
> tower/sewage treatment plant/power sub station or other  city owned
> property.  Your L1 customer isn't going to have that access (not with the
> city manager/mayor/council's knowledge anyway) because of regulatory and
> liability reasons.  If you do home run everything you still have an access
> challenge (where are you going to be able to give access to these customers
> economically?) but its probably more solvable since its one spot.  You also
> increase your costs by home running each connection, but that may or may
> not be a deal breaker in your situation.

The point is to home run everything to a location where those issues are
addressed. Addressing those issues is a critical part of the design.

> 3)  Your going to have to do a lot more work since at L1 all of the rough
> edges and sharp corners are there to be dealt (like someone grabbing the
> wrong cable from the patch panel) there is simply no inexpensive method of
> safeguarding L1 adds, changes, and modifies so either you do them or you
> let your L1 customer do them and run a risk.  This is also something that
> the city management is going to have concerned over.

IMHO, you do them. The risk the other way is too great. However, part of
the lease is the cost of those personnel, so, since you're operating on
a pure cost recovery basis, that's probably OK. It's unlikely to cost
significantly more (in fact likely quite a bit less) than the provider(s)
would be paying for their own tech(s).

> 4)  Physical layer troubleshooting is much harder than layer 2 and up.
> Having several organizations and potentially several different equipment
> vendors and L2 technologies will be very tough to deal with over time.

I've usually found physical layer troubleshooting to be quite a bit easier.
If you get good OTDR results end-to-end, you don't have a physical layer
problem. If you don't get good OTDR results, then if you have good records,
you should be able to get a pretty good idea where the problem is.

Admittedly, I haven't done a lot of this in the outside world, but light
is light. Other than not knowing where your fiber actually goes, what are
the additional variables that make this so insurmountable?

> 5)  I've seen at least 5 muni networks try this and not succeed.  If you
> include non-muni networks with similar characteristics (like EMCs) then
> I've seen it tried more than a dozen times with no success (or interest)
> beyond a few dark fiber set ups for point to point connections across town.

I believe that Sweden operates largely on this model and that the Australia
NBN project does as well.

I would say that the Swedish model is a definite success.

Owen