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@leitl.org> To: Tyler Durden <camera_lumina@hotmail.com>, cypherpunks@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
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