[IP] EFF: Secret Surveillance Evidence Unsealed in AT&T Spying Cas
Tyler Durden
camera_lumina at hotmail.com
Thu Jun 14 09:54:29 PDT 2007
Well, this barely counts as WAN! My expertise increases exponentially as you
get to the core.
However, I do happen to know a small amount here, and the issues are
numerous and tricky.
Let's go for the main question:
>Is there a special device
>class for residential fiber Ethernet, and if yes, how much do these
>things cost?
Well, basically yes: It's called PON (Passive Optical Network) and there are
several flavors. The original was A-PON, wherein a home-based ONT that sits
on the outside of a residence outputs ethenet into the home and maps the
packets onto ATM over OC-12 upstream (as I remember) and OC-48 down. It's a
weird technology in that a single OC-48 is split lots of times (32, I think)
and each ONT just grabs the ATM VPI that corresponds to its owner (upstream
is even weirder: All of the upstream ONTs time their burst-mode output so as
to glue together a single coherent OC-12 upstream).
The real winner here is probably going to be GPON, which is basically an
optically split ethernet. Each ONT is given a 'window' wherein it can
broadcast upstream packets. I'm not too in touch with this technology, but
I'd suspect a single GbE port on the headend switch/router can support 64
endusers. And often, these endusers can be an apartment building with a
switch in the basement. If you only have a single fiber coming out of the
headend, then the 'obvious' upgrade is to use Coarse-DWDM which can easily
provide up to 16 cheap wavelengths. In other words, that's 16 GbE ports (no,
the PHY is not quite the same as the GBICs have to be burst mode).
BT and other big companies have been building out fiber-to-the-home
architectures using PONs, and I think I've heard prices quoted for the ONT
as low as $250, but I could be wrong.
Of course, there are lot of people who don't like PON, and depending on how
much fiber you've got in the nieghborhood and the quality of the copper in
the last mile, PON might easily not deliver as much bandwidth as a hybrid
approach.
-TD
>From: Eugen Leitl <eugen at leitl.org>
>To: Tyler Durden <camera_lumina at hotmail.com>, cypherpunks at jfet.org
>Subject: Re: [IP] EFF: Secret Surveillance Evidence Unsealed in AT&T
>Spying Cas
>Date: Thu, 14 Jun 2007 12:50:53 +0200
>
>On Thu, Jun 14, 2007 at 06:03:18AM -0400, Tyler Durden wrote:
>
> > Well, the need for optical amplifiers is not so much a power
>availability
> > issue so much as a complexity issue. If one has dozens or hundreds of
> > fibers, remember that each of these is going to be some random
>wavelength
>
>Since you're about the only authority on WAN networking I know, and I've
>been slowly starting using low-end (GBIC based monomode and multimode
>WAN) recently, I have the following questions for you:
>
>a stupid way to wire up the neighbourhood with fiber is connect
>every household with medium converter or a GBIC to a large switch,
>and once you're running out of ports to build a tree of those.
>However, I've only come across some 8-16 porters which take optical
>input and are cheap. Do you use vanilla large switches, and use media
>converters for each, something like a large patch panel, with
>glass coming in, and copper going out? Is there a special device
>class for residential fiber Ethernet, and if yes, how much do these
>things cost?
>
>If you don't want to use routers, one has to use trees of switches.
>Newer switches can manage redudant links/loops with spanning-tree,
>and similiar. Is there a way to mesh up a tree of switches not
>using a real router? (Even though a low-end box like a X2100 M2
>can probably saturate all onboard GBit ports, and then some 4 more),
>at wire-speed.
>
>--
>Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
>______________________________________________________________
>ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org
>8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE
_________________________________________________________________
Like puzzles? Play free games & earn great prizes. Play Clink now.
http://club.live.com/clink.aspx?icid=clink_hotmailtextlink2
More information about the cypherpunks-legacy
mailing list