----- Original Message -----
From: "Mikael Abrahamsson" <swmike@swm.pp.se>
On Tue, 22 Jul 2014, Scott Helms wrote:
One of the main problems with trying to draw the line at layer 1 is that its extremely inefficient in terms of the gear. Now, this is in large part a function of how gear is built and if a significant number of locales went in this direction we _might_ see changes, but today each ISP would have to purchase their own OLTs and that leads to many more shelves than the total number of line cards would otherwise dictate. There are certainly many other issues, some of which have been discussed on this list before, but I've done open access networks for several cities and _today_ the cleanest situations by far (that I've seen) had the city handling layer 1 and 2 with the layer 2 hand off being Ethernet regardless of the access technology used.
Stop doing PON then. Use point to point fiber, you get 40-48 active customers per 1U. I'd imagine there might be newer platforms with even higher densities.
Yes, there are many examples of L2 being used but in order to deliver triple play the L2 network won't be purely L2, also BCP38 needs it to start doing L2.5+ functions, meaning it's harder to deploy new servies such as IPv6 because now the local network needs to support it.
It's cleaner just to do L1 and aggregate thousands or tens of thousands of residential properties in the same place.
I believe you've misunderstood Scott's point. The goal of layer-restriction is to encourage competition. The underlying goal is "reducing the barrier to entry of a new ISP". The less equipment such a new ISP has to provision, the lower that barrier is. If all you have to provision is a couple GE/10GE ports on your core switch, that's an order of magnitude easier than any type of optical termination equipment, for you as a potential ISP customer. To make this work, the fiber operator *has to make it easy for ISPs to become their clients* as well... Cheers, -- jra -- Jay R. Ashworth Baylink jra@baylink.com Designer The Things I Think RFC 2100 Ashworth & Associates http://www.bcp38.info 2000 Land Rover DII St Petersburg FL USA BCP38: Ask For It By Name! +1 727 647 1274