Putting routers and DLAMs each CO is simply not affordable for any but the largest providers like XO. I expect Japan with its compact population centers may be different, but in the USA there are not enough people connected to any but the largest COs to make it affordable. I'm not stuck on using ATM (I used it only as an example), any L2 technology will work. One of our providers uses an Ethernet VLAN per customer endpoint and hands off bunches of VLANs to us over fiber. -----Original Message----- From: Masataka Ohta [mailto:mohta@necom830.hpcl.titech.ac.jp] Sent: Wednesday, February 06, 2013 4:48 PM To: Scott Helms Cc: NANOG Subject: Re: Muni fiber: L1 or L2? Scott Helms wrote:
Actually, at the level that Eric's discussing there isn't any real drawback to using ATM.
High cost is the real drawback.
but the basic concept is not bad.
It is not enough, even if you use inexpensive Ethernet. See the subject.
Why?
Because, for competing ISPs with considerable share, L1 unbundling costs less. They can just have routers, switches and DSL modems in collocation spaces of COs, without L2TP or PPPoE, which means they can eliminate cost for L2TP or PPPoE. Masataka Ohta