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Journal by rdewald

I was doing some research for a project and happened back here. Hello slashdot.

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Comment: Re:Nice (Score 1) 294

by Cyberdyne (#48725745) Attached to: BT, Sky, and Virgin Enforce UK Porn Blocks By Hijacking Browsers

I do have to wonder, though - What will the UK nannies do if essentially the entire country opts out and says "Yeah, thanks, but we want our porn and violence, thankyouverymuch"?

That's almost precisely why this is being done in the first place. A Member of Parliament named Claire Perry saw a bandwagon she could jump on, using a tale she concocted about her daughter Googling for cookie recipes and getting porn instead, and used this as an excuse to hold a "hearing" on the subject. The hearing found that most parents were already aware of parental controls, had the option and chose not to use them; she took this as an excuse to push filters harder, demanding that ISPs make them opt-out rather than opt-in in hopes of boosting uptake. (Funnily enough, several of the people testifying at her "hearing" happened to be from companies involved in the filtering business...)

Since the biggest four ISPs agreed to force all their customers to reiterate specifically that they still don't want filtering, hopefully this will be enough to stop these idiots pushing any harder for a while - albeit having forced them to flush money away buying in a filtering system most customers never wanted. My current (much smaller, tech-savvy) ISP is very much opposed to this nonsense, which is one reason I'm happy to be their customer - though unfortunately this has already drawn government attention (after which, they had to take on an extra member of staff and upgrade transit pipes to handle the increased demand - probably not the result the politician expected!)

Comment: Re:AC current maintained only by tradition? (Score 2) 578

by Cyberdyne (#48724569) Attached to: What Language Will the World Speak In 2115?

I can see applications for DC power distribution in certain circumstances. High-density computing, for one - why have a full mains PSU in every server? It's expensive, more points of failure, and you end up going from mains incoming to DC for the UPSs inverted to AC to send back to the servers converted back to DC for use inside - and those inverters are not that reliable too. It makes more sense to feed all the servers off of DC (Usually 48V - any lower and current gets silly), and have the power supply stuff all centralized. All the servers need is a DC-DC converter for each rail.

Telcos have been doing exactly that for decades now: all their exchanges and much of the optical kit runs on -48V: it's a low enough voltage to be safe to work on when live (negative rather than positive because that protects against corrosion on the wires), easy to combine sources (a diode will do it), no need to "switch" to backup power (just connect your load, battery and source together, job done).

Facebook went the other way for a large server farm, though: running 480V 3-phase AC to the racks (277V per phase). Cleverly, though, they don't need to convert DC from the batteries to AC in power cuts: the mixed DC/AC bus feeds switch-mode power supplies which convert incoming power to DC anyway, so switching between AC utility power and DC battery power doesn't matter. Pretty clever really, IMO.

Comment: Re:One fiber to rule them... (Score 1) 221

by Cyberdyne (#48721387) Attached to: Google Fiber's Latest FCC Filing: Comcast's Nightmare Come To Life

Why not just run one fiber, ditch all the copper, terminate it at the local POP and then allow various vendors access to that fiber and compete for my business?

Home-run fiber per home would get very expensive I think - normally the idea is something like PON (Passive Optical Networking), where a single fiber is split across a few dozen locations, rather like gas, electricity and water/drainage. Telephone service is, I think, unique in using home-run wiring back to the exchange; even there, the faster post-ADSL services such as VDSL share a single fiber link back to the exchange: my current 80/20 service is VDSL2 as far as the cabinet around the corner - all the hundred or so users on that cabinet share a single fiber from there.

Right now in the UK BT have this set up so everyone on FTTC or FTTP is connected to an Ethernet switch in the exchange, with their own VLAN; any ISP can connect their own equipment to that switch and get your VLAN trunked onto their Ethernet port, or they can pay BT to run PPPoE over that and transport it to them. That probably works better in practice than physically patching a few thousand fiber connections directly to different ISPs in each exchange building - my inner geek would love a straight through fiber link, but how much more would that cost?

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