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Closing In On 1Gbps Using DSL
angry tapir writes "DSL vendors are using a variety of methods, such as bonding several copper lines, creating virtual ones, and using advanced noise cancellation to increase broadband over copper to several hundred megabits per second. At the Broadband World Forum in Paris, Nokia Siemens Networks became the latest vendor to brag about its copper prowess. It can now transmit speeds of up to 825M bps over a distance of 400 meters."
Um. great, how many people are within 2 city blocks of the local wire center?
They need to be working on extending the speeds out past 15,000 feet (5,000M) if they want folks to get excited.
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Unfortunately, I still find myself with a 2 Mbps download speed tops. This technology needs to be actually utilized! It's killing me to read this stuff and then never see it in action.
Someone please explain how this works. Is this some bizarre artifact of the signaling protocol, such that the only way to overcome a design flaw is to use some incomprehensible technique treating physical wires as virtual wires? How can that possibly be better than just natively signaling faster on the wires?
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"advanced noise cancellation"
So that rules out most of the internet and email then, eh?
And with a 25 GB cap, you'll get several seconds on full-on internet!
They are using 4 pairs to achieve that 825 Mbps speed.
Note that 1000BASE-T also uses 4 pairs to achieve 1000Mbit over a shorter 100 meters. I'm curious what maximum range 1000BASE-T will actually work at (100m is guaranteed), and if it were to work at 400m, what the bandwidth would be.
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825Mbs @ 400m ... I'd rather not live INSIDE the CO, thanks....
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I briefly had ADSL and it was crap compared to cable modem. People forget the ASYMMETRIC part of DSL. In my usage I really felt this when using the net. Lots of lags etc. I switched to a cable modem and it was night and day better in my usage. Granted this was many years ago so perhaps it's better now?
I'm deploying docsis 3.0 networks today that can reach 200 mbit today. Only real limitation is the money to upgrade the gear and shifting around tv channels to free frequencies. Expect to see major pushes in 2011 by all carriers.
That means I'll soon have 825M bps down and 1M bps up to look forward to.
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For gaming, all that matters is ping. You need little bandwdith by today's standards. I've yet to see any evidence that DSL is reliably lower ping than cable. I know it can be much high ping, I've had that myself. When I was with Speakeasy, they actually switched the connection up to Seattle before the first hop. There are DSL switches, just like Ethernet, and Covad switched it up there for them. A low ping to a site for me was 150ms with that connection. Compare that to my current cable connection which pings like 24ms to Google.
Also oversubscription isn't such a problem these days. Cable companies have built fiber out quite far, and as such can segment down the network a whole lot. Plus the new equipment can operate on multiple channels (DOCSIS 3 is actually done through channel bonding). So you can have multiple frequencies that different customers are on, which of course don't share bandwidth.
Finally there's always oversubscrtiption at various levels, even with DSL, even with big lines like DS-3s. It is just a question of doing a good job with it. A good or a bad job can be done with any technology. DSL doesn't mean no problems. It could be more or less as big a problem as cable when they do it wrong. Peopel have connections to a DSLAM, which is in a non-fiber area and just has a couple DS-1s or a DS-3 back to the central office. They've got too many people, the backhaul gets overloaded, speeds are slow. Seen it happen with Qwest more than a few times.
It is not a matter of DSL vs cable, it is a matter of implementation. Implement either poorly and you'll have problems. Implement either well and it can be good.
VDSL2, VDSL was crap which is why half baked solutions like SHDSL came into existence. If Slashdot guys can't get this right, then who is it providing information to the masses that for years talked about 3 and a quarter inch disks and call the computer "the cpu"?
And VDSL2,3,... is the short term future. Any time there's a nasty hack like DSL to cope with delivering over existing lines, at some point, it becomes necessary to replace the old, aging cables with something that is capable of lower noise. When this happens, I hope for your sake that they either replace it with fiber or 8-pair cat-6 (or better). Electrically isolated Ethernet is also a hack, but at least it's a clean hack. There just is no substitute for running a clean, environmentally secure solution like fiber.
For outdoor data requirements, fiber is the ONLY solution. When you stop demanding it, the service providers will start thinking you're happy with their hold-me over hacks.
The 30 up exists simply because it doesn't cost them anything extra to provide it. The fact is, they can oversell the up by a factor of 10 and probably no one would ever notice it. It's because 90% of all fiber traffic is downstream. That's because while there are some people who are sharing their entire movie and music collections with the masses, most people are watching youtube, hulu, etc...
So, while you get 30 up, and when connecting to others on the same provider's network, you're getting 30 up, the provider is simply throttling the overall up at their data center where they host servers for other businesses.
Remember the provider isn't paying for 10 terabit up and 500 gigabit down. They have a large group of switched fibers. They still run much of it over OC-(insert big number here) networks as Sonet is for the time being a hell of a lot easier to load balance and provide redundancy on than using massive Ethernet load balanced trunks.
So, what are they going to do with 9.5 terabits of unused upstream anyway?
Also remember that with the exception of P2P traffic, upstream between providers is becoming less important since Akamai, Google, etc... are distributing content all over the Internet anyway. If you're a provider with so much as 4U of rack space to spare, Google or Akamai will gladly install a caching server that will offload insane amounts of traffic from you. So if you have 100,000 users all watching the same viral video on youtube, after the first time it's viewed on your ISP, the video is probably located on a server at your ISP.
Yes, yes, we all are pretty much aware of DSL limitations by now. But the point is as fiber is pushed into the neighborhood the distance over copper is reduced. Because what used to have to be located in the nearest exchange can now be in the distribution panel on the corner of the block.
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