Muni fiber: L1 or L2?

Scott Helms khelms at zcorum.com
Wed Feb 6 15:10:41 UTC 2013


On Tue, Feb 5, 2013 at 9:40 PM, Eric Wieling <EWieling at nyigc.com> wrote:

> The ILECs basically got large portions of the 1996 telecom reform rules
> gutted via lawsuits.  DSL unbundling was part of this.   See
> http://quello.msu.edu/sites/default/files/pdf/wp-05-02.pdf   The ILECs
> already need a DSLAM in each CO and already use ATM PVCs to provide L2
> connectivity from the DSLAM to their IP network, I don't think it is that
> much more expensive to allow other ISPs an ATM PVC into their network.
> ATM may not be the best technology to do this, but the basic concept is not
> bad.  Ethernet VLANs would be another option, as would Frame Relay, as
> would simply DAXing multiple 64k channels from the customer endpoint to the
> ISP if you want more L1 style connectivity.
>

Generally the way this was done by all of the RBOCs (except Qwest) was via
a L2TP tunnel to hand off the PPPoE/oA tunnel prior to it being
authenticated.  The connections from BellSouth and some of the other
operators was ATM but that was because they didn't want to have to do SAR
on all those frames/cells on their existing gear.



>
> What *I* want as an ISP is to connect to customers, I don't care what the
> local loop is.   It could be fiber, twisted pair, coax, or even licensed
> wireless and hand it off to me over a nice fat fiber link with a PVC or
> VLAN or whatever to the customer endpoint.   What I don't want is to have
> to install equipment at each and every CO I want to provide service out of.
>  This would be astoundingly expensive for us.
>

This is what I see most commonly.


>
> -----Original Message-----
> From: Masataka Ohta [mailto:mohta at necom830.hpcl.titech.ac.jp]
> Sent: Tuesday, February 05, 2013 7:42 PM
> To: nanog at nanog.org
> Subject: Re: Muni fiber: L1 or L2?
>
> Eric Wieling wrote:
>
> > In the past the ISP simply needed a nice big ATM pipe to the
> > ILEC for DSL service.   The ILEC provided a PVC from the
> > customer endpoint to the ISP.  As understand it this is no longer the
> > case, but only because of non-technical issues.
>
> The non-technical issue is *COST*!!!!!
>
> No one considered to use so expensive ATM as L2 for DSL unbundling, at
> least in Japan, which made DSL in Japan quite inexpensive.
>

AFAIK all ADSL is ATM at layer 2, including Japan.  Did they deploy a
different DSL technology there?


>
> > We currently use XO, Covad, etc to connect to the customer We get a
> > fiber connection to them and the provide use L2 connectivity to the
> > custom endpoint using an Ethernet VLAN,
> > Frame Relay PVC, etc complete with QoS.   I assume XO,
> > etc use UNE access to the local loop.   There is no reason
> > a Muni can't do something similar.
>
> Muni can. However, there is no reason Muni can't offer L1 unbundling.
>
>                                                 Masataka Ohta
>
>
>


-- 
Scott Helms
Vice President of Technology
ZCorum
(678) 507-5000
--------------------------------
http://twitter.com/kscotthelms
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