----- Original Message -----
From: "Scott Helms" <khelms@zcorum.com>
Owen I think the confusion I have is that you seem to want to create solutions for problems that have already been solved. There is no cost effective method of sharing a network at layer 1 since DWDM is expensive and requires compatible gear on both sides and no one has enough fiber (nor is cheap enough in brand new builds) to simply home run every home and maintain that.
That's my fundamental design assumption, and you're the first person to throw a flag on it. I'm hearing $700 per passing and $600 per sub; those seem sustainable numbers for a 30 year service life amortization.
I'm not yet 100% clear if that's layer 1 only or layer 2 agg as well.
OK, think about it like this. The most efficient topology to provide both coverage and resiliency is a ring with nodes (shelves) from which end users are connected. That ring (usually Gig or 10Gig Ethernet today) needs to be connected to a central location so you can interconnect to other providers (your ISP customers) and/or to connect to the Internet if the city is also going to provide direct L3 services. If you instead push down a L1 path then the most expensive pieces of gear in the access network (the FTTx shelves) have to be replicated by everyone who wants to offer services.
In short, you're saying I *must* have a ring with active equipment scattered around it, and I *cannot* home run each property. No one else is saying that, and you don't appear to justify it later in this email:
This bad not just from the initial cost perspective but because people and companies that identify themselves as ISPs seldom know anything beyond Ethernet and IP and then only in a few manufacturers (mainly Cisco and Juniper). They are most certainly not comfortable working with Calix, Adtran, and the rest of the carrier (formerly telco) equipment manufacturers.
Well, ok, but those people who are not comfortable handling access gear like the Calix will be L2 clients, anyway, taking a groomed 802.1q handoff from my Calix/whatever core, so they won't *have* to care. L1 access will be there a) cause it has to be anyway, to keep active equipment out of the outside plant, b) for people who really want PtP, and 3) for ISPs large enough to want to do it themselves, if any show up (they admittedly might not; we're only 6k households).
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?
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.
You can of course lease someone a dark fiber from point A to point B, but that's not a traditional way of partnering with ISPs and in any case will only be feasible for a small number of connections since you (probably) can't afford to home run each location in your network.
Well, I'll have to see on that, won't I? That's my next practicality checkpoint; fiber passing costs.
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.
You just changed gears again, no?
I'm not trying to share L1 *drops*. I'm trying to make it possible to share *the entire L1 deployment between providers*, a drop at a time.
That's what I'm trying to tell you can't do. Its more expensive in both the initial and long term costs.
I can see 'initial', maybe, but if I reduce the utility of the field network by putting active equipment in it, then I've already raised the OPEX, substantially, as well as reducing the intrinsic value of that network. Cheers, -- jra -- Jay R. Ashworth Baylink jra@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