Muni fiber: L1 or L2?

Wed Feb 6 22:31:35 UTC 2013

Scott Helms wrote:

> The cost difference in a single interface card to carry an OC-3/12 isn't
> significantly more than a Gig-E card.  Now, as I said there is no advantage
> to doing ATM, but the real cost savings in a single interface are not
> significant.

You miss ATM switches to connect the card to multiple modems.

>> 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.

> You realize that most commonly the L2TP LAC and LNS are just routers right?

Who, do you think, operate the network between LAC and LNS?

The largest DSL operator in Japan directly connect their routers
in COs with dark fibers to form there IP backbone. There is no
LAC nor LNS.

> You're not getting rid of boxes, you're just getting rid of the only open
> access technology that's had significant success in the US or Europe.

At least in France, fiber is regulated to be open access at L1
much better than poor alternative of L2 unbundlinga as
Jerome Nicolle wrote:

> Smaller ISPs usually go for L2 services, provided by the
> infrastructure operator or another ISP already present on
> site. But some tends to stick to L1 service and deply
> their own eqipments for many reasons.

						Masataka Ohta