Muni fiber: L1 or L2?

Owen DeLong owen at delong.com
Thu Jan 31 23:32:49 UTC 2013


Scott,

Respectfully, you appear to be misinterpreting what I am saying.

I'm saying you put the splitter next to the OLT and then run multiple fibers from there to the subscribers IN THE MMR.
Each provider has their own splitters and OLTs, but all the splitters are in the MMR and the customers have home
run fiber to the MMR.

In other words:

OLT->SPLITTER->XC to customer port in MMR->Last mile infrastructure->ONT->Customer.
instead of the traditional
OLT->Last mile infrastructure->Splitter->ONT->Customer.

All I'm doing is moving the location of the split closer to the OLT and making the customer fiber run
longer.

I'm not proposing multiple providers sharing a splitter. I'm proposing longer customer runs to the
splitter and putting all of the splitters from all of the providers in the same room.

Owen

On Jan 31, 2013, at 14:04 , Scott Helms <khelms at zcorum.com> wrote:

> Owen,
> 
> Respectfully, it doesn't work that way.  You have to understand that the splitter is a specific part of the PON architecture and they don't have multiple outputs to connect to several OLTs like a patch panel or even a switch you can VLAN.  One fiber goes to the splitter on the provider side and then from there it splits into 8/16/32/64 connections that go to customers.  You can't exchange one of the customer side ports to make another provider interface.  That's not to say you couldn't build a splitter to do just that, but to do that you have to get the vendors on board and currently they simply aren't nor are the people who build PON networks asking for that feature.  You also have to deal with the mechanics of turning up the port, ie deciding which OLT to send that color to, which kind of kills the passive part of PON.
> 
> 
> On Thu, Jan 31, 2013 at 4:36 PM, Owen DeLong <owen at delong.com> wrote:
> 
> On Jan 31, 2013, at 13:27 , Scott Helms <khelms at zcorum.com> wrote:
> 
>> Owen,
>> 
>> You can't share access from one splitter to multiple OLTs so the location of the splitter isn't important.  AFAIK there is simply no concept for that idea in any of the PON specs and its certainly not something that Calix/Adtran/Zhone/Alcatel/$gear_maker are building right now.  For that matter I can't think of a single piece of gear beyond DWDM/CWDM that actually operates are layer 1 to allow that kind of split and then its very limited in terms of the channels available and not suitable for the kind of deployment I think you're describing.
>> 
> 
> 
> Sure it is...
> 
> If you have an MMR where all of the customers come together, then you
> can cross-connect all of $PROVIDER_1's customers to a splitter provided
> by $PROVIDER_1 and cross connect all of $PROVIDER_2's customers to
> a splitter provided by $PROVIDER_2, etc.
> 
> If the splitter is out in the neighborhood, then $PROVIDER_1 and $PROVIDER_2
> and... all need to build out to every neighborhood.
> 
> If you have the splitter next to the PON gear instead of next to the subscribers,
> then you remove the relevance of the inability to connect a splitter to multiple
> OLTs. The splitter becomes the provider interface to the open fiber plant.
> 
> Owen
> 
>> 
>> On Thu, Jan 31, 2013 at 4:15 PM, Owen DeLong <owen at delong.com> wrote:
>> That's why I'm not advocating for open access, I'm advocating for L1/L2 provider
>> separation and a requirement that the L1 access itself be open.
>> 
>> I have yet to get a firm answer, but as I understand PON, it doesn't actually matter
>> so much whether you put the splitter/combiner in an MMR or near the CPE.
>> Obviously, most of the "economy" of PON comes from putting the splitter near
>> the subscriber, but so does the loss of open access at L1.
>> 
>> OTOH, if you build out fiber from a city or neighborhood or whatever to an
>> independent MMR, I don't believe there's any reason you couldn't cross-connect
>> various users home-run fibers to splitter/combiners inside the MMR and then
>> run that to a PON system (if you really wanted to for some reason).
>> 
>> Owen
>> 
>> On Jan 31, 2013, at 12:45 , Scott Helms <khelms at zcorum.com> wrote:
>> 
>>> Owen,
>>> 
>>> The short answer is that you don't today and it will be a long time (if ever) before its feasible.  Europe is commonly held up as an example of an area where open access works and if you stick to DSL networks that's true.  The problem is that the DSL networks (by and large) in Europe aren't expanding and are being overtaken by FTTx and to a lesser extent DOCSIS.  The reasons why this is so can be debated, but it is definitely happening and given that trend there is very little incentive for the equipment manufacturers and protocol groups to build in open access as a core part of their design as it was in DSL, especially with PPPoX authentication.  
>>> 
>>> Now, once networks get to purely active Ethernet things get more simple technically, after all you easily do QinQ tagging, but there has been little movement even in regulation tolerant Europe to force operators to open up and its much less likely to happen here in the US.  Whats more many of the FTTx builds aren't Ethernet today and doing open access on any flavor of PON is so painful operationally that it simply won't happen.
>>> 
>>> 
>>> On Thu, Jan 31, 2013 at 3:31 PM, Owen DeLong <owen at delong.com> wrote:
>>> 
>>> On Jan 31, 2013, at 07:07 , Ray Soucy <rps at maine.edu> wrote:
>>> 
>>> > Late to the conversation, but I'll chime in that we established a
>>> > model in Maine that is working pretty well, at least for middle-mile
>>> > fiber.
>>> >
>>> > When we started building out MaineREN (our RON) we decided that having
>>> > the University own the fiber would tie it up in political red tape.
>>> > So much so that it would ultimately not be made available to the
>>> > private sector (because incumbents would accuse us of competing with
>>> > them using public funds).  We knew this because we had already spent a
>>> > year in the legislature fighting off industry lobbyists.
>>> >
>>> > Obviously there are considerable investments in such infrastructure
>>> > that many private companies are unwilling or unable to make in rural
>>> > areas (ROI takes too long), so we really wanted to make sure that
>>> > future facilities would be built out in a way that would allow service
>>> > providers to expand into the state cheaply, encourage competition, and
>>> > ultimately provide better services at lower costs.
>>> >
>>> > The goal was to establish geographically diverse, high stand-count,
>>> > rings to reach the majority of the state, so we pitched it in a
>>> > public-private partnership to go after Recovery Act funding.
>>> >
>>> 
>>> That's also a worthy goal, but it doesn't address the issues that
>>> are the subject of this conversation. Middle-mile solutions
>>> like this are not all that uncommon, even in such backwards
>>> places (when it comes to networking infrastructure) as silicon
>>> valley.
>>> 
>>> Where we still have a serious lack of deployment and virtually no
>>> competition, even in most major metros, is the last mile.
>>> 
>>> > As of a few months ago the build-out is complete, and the first
>>> > networks to make use of the fiber are starting to come online
>>> > (including MaineREN).
>>> >
>>> > The way we did it was to have the state government create a new public
>>> > utility designation of "Dark Fiber Provider".  There are a few rules
>>> > in place to keep things fair: Mainly they're forbidden to provide lit
>>> > services and they're required to provide open access to anyone at
>>> > published rates.
>>> >
>>> 
>>> This is definitely a good first step if you can get it through the legislative
>>> process without having the $TELCOS and $CABLECOS lobby against
>>> it to the point of death or dismemberment.
>>> 
>>> > The result is "Maine Fiber Company":
>>> >
>>> > http://www.mainefiberco.com/
>>> >
>>> > It's still early on, but I'm anxious to see how things look in 10 years or so.
>>> >
>>> 
>>> Sounds great... Now, the $50,000,000 question... How do we replicate
>>> that model at the consumer level?
>>> 
>>> > A lot of people who like the idea of what we've done aren't sure if
>>> > it's a good model to apply for last mile fiber.  Personally, I think
>>> > replicating this model to deliver dark fiber to the home (much like
>>> > electricity) is the only way we'll be able to shield providers from
>>> > having to make major investments to deliver the level of service we
>>> > really need.  By keeping it as a dark-fiber only service, you create
>>> > an environment where there is competition instead of one provider
>>> > keeping speeds low and prices high.
>>> 
>>> That's certainly the ideal, yes.
>>> 
>>> > I initially thought having L2 separation would be good in that service
>>> > changes could be done remotely, etc.  But after giving it some
>>> > thought, I think it places way too much potential for L2 to be the
>>> > bottleneck or source of problematic service and if it's provided by a
>>> > public utility or municipality it could take very long to fix (if it
>>> > get's fixed at all) due to politics and budget hawks.  I really want
>>> > to have choice between providers even at the L2 level.
>>> 
>>> There are cases where the lack of L2 services could pose a barrier
>>> to entry for competition. That's why I proposed the following requirements:
>>> 
>>> 1.      Must sell dark fiber to any purchaser.
>>> 2.      Must sell dark fiber to all purchasers on equal terms.
>>>         (There must be a published price list and there cannot be deviations
>>>         from that price list. If the price list is modified, existing customers
>>>         receive the new pricing at the beginning of their next billing cycle.)
>>> 3.      May provide value-added L2 services
>>> 4.      If L2 services are provided, they are also subject to rule 2.
>>> 5.      May not sell L3 or higher level services.
>>> 6.      May not hold ownership or build any form of alliance or affiliation with
>>>         a provider of L3 or higher level services.
>>> 
>>> Owen
>>> 
>>> >
>>> >
>>> >
>>> >
>>> > On Tue, Jan 29, 2013 at 12:54 PM, Jay Ashworth <jra at baylink.com> wrote:
>>> >> ----- Original Message -----
>>> >>> From: "Leo Bicknell" <bicknell at ufp.org>
>>> >>
>>> >>> I am a big proponent of muni-owned dark fiber networks. I want to
>>> >>> be 100% clear about what I advocate here:
>>> >>>
>>> >>> - Muni-owned MMR space, fiber only, no active equipment allowed. A
>>> >>> big cross connect room, where the muni-fiber ends and providers are
>>> >>> all allowed to colocate their fiber term on non-discriminatory terms.
>>> >>
>>> >>> - 4-6 strands per home, home run back to the muni-owned MMR space.
>>> >>> No splitters, WDM, etc, home run glass. Terminating on an optical
>>> >>> handoff inside the home.
>>> >>
>>> >> Hmmm.  I tend to be a Layer-2-available guy, cause I think it lets smaller
>>> >> players play.  Does your position (likely more deeply thought out than
>>> >> mine) permit Layer 2 with Muni ONT and Ethernet handoff, as long as clients
>>> >> are *also* permitted to get a Layer 1 patch to a provider in the fashion you
>>> >> suggest?
>>> >>
>>> >> (I concur with your 3-pair delivery, which makes this more practical on an
>>> >> M-A-C basis, even if it might require some users to have multiple ONTs...)
>>> >>
>>> >> Cheers,
>>> >> -- jra
>>> >> --
>>> >> Jay R. Ashworth                  Baylink                       jra at 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
>>> >>
>>> >
>>> >
>>> >
>>> > --
>>> > Ray Patrick Soucy
>>> > Network Engineer
>>> > University of Maine System
>>> >
>>> > T: 207-561-3526
>>> > F: 207-561-3531
>>> >
>>> > MaineREN, Maine's Research and Education Network
>>> > www.maineren.net
>>> 
>>> 
>>> 
>>> 
>>> 
>>> -- 
>>> Scott Helms 
>>> Vice President of Technology 
>>> ZCorum 
>>> (678) 507-5000 
>>> -------------------------------- 
>>> http://twitter.com/kscotthelms 
>>> -------------------------------- 
>> 
>> 
>> 
>> 
>> -- 
>> Scott Helms 
>> Vice President of Technology 
>> ZCorum 
>> (678) 507-5000 
>> -------------------------------- 
>> http://twitter.com/kscotthelms 
>> -------------------------------- 
> 
> 
> 
> 
> -- 
> Scott Helms 
> Vice President of Technology 
> ZCorum 
> (678) 507-5000 
> -------------------------------- 
> http://twitter.com/kscotthelms 
> -------------------------------- 



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