Closing In On 1Gbps Using DSL 230
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."
Re:400M ? (Score:3, Informative)
Re:And yet, I'm stuck (Score:3, Informative)
Direct link to graphic (Score:5, Informative)
https://gigaom.files.wordpress.com/2010/04/dslphantommodeexplained.jpg [wordpress.com]
Re:400M ? (Score:5, Informative)
Re:As long as it's Adsl I don't want it (Score:3, Informative)
An ADSL line is divided up into multiple 4KHz bands, each one carrying either 33.6kbit up, or 33.6kbit down. That's what the "Asymmetric" means: each band is either upload or download, but not both. Cable is exactly the same. On a normal ADSL1 connection, the bottom portion of the frequencies will be set aside for upload, and the top will be set aside for download, and you can definitely upload at the same time as download. Usually you can't get nearly as fat a pipe as you can with cable (though in some areas, DSL actually offers faster speeds), but for most use of the Internet you're limited by latency, not bandwidth, because the first 82kb of any file you download on the 'net is transmitted during the TCP Slow Start phase of the connection, and most of the files on the 'net are smaller than 82kb.
Despite the added overhead of using an ATM frame to encapsulate your ethernet packets, DSL usually offers much lower latency than cable, because of differences in the way the information is encoded end to end. The difference... for casual surfing and online gaming, DSL is better. For downloading large files, Cable is better. Of course, your latency on ADSL depends a lot on the type of error correction your ISP is using... whether you're on an interleave, a partial interleave, or a fast weave.
http://en.wikipedia.org/wiki/Slow-start [wikipedia.org]
Re:4 pairs (Score:4, Informative)
I doubt most of the copper POTS wiring out there is cat 3. The phone wire used in most homes is the old 4 conductor cable that did not have twisted pairs. Nowadays I believe most of the four conductor phone cable is indeed twisted and meets CAT 3 standards. I bought some at home depot not too long ago and it was 4 conductor CAT 3 twisted pair with RED/GREEN and BLACK/YELLOW pairs. The non twisted pair might still be sold so no guarantee there.
And that is just the home wiring. Who knows what crusty old non twisted pair cable lurks between homes and the central office.
And getting back to the grand parent poster:
1000BT is an IEEE 802.3-2008 standard. It not only defines the data layer (how the bits are transmitted) but also the physical link which defines the electrical interface.
DSL is different than the 802.3 standard both at the data link layer and the physical layer. So its an apples to oranges comparison. Gigabit is Ethernet and DSL and other broadband technologies are completely different.
Re:400M ? (Score:4, Informative)
Me. I've just had vsdl service installed, which utilizes QWest's FTTN(Fiber To The Node) service. The DSLAM is about 2 blocks away from my house. I'm getting 20mbit down/5 mbit up. It's awesome. I see it as the future of DSL, simply bridging the last mile problem from fiber nodes.
I'm on U-Verse, and have been very pleased with it. U-Verse is also VDSL, and while it's no gigabit connection it works very well. Somewhat ironically (well, irritatingly) there's an AT&T VRAD right across the street from my house, not fifty feet away. But I'm not connected to it: I'm running from a box down on the main drag, maybe a mile away. I'm currently on the 12 mbit/sec plan (saved a few bucks) but I get about 15 which is fine for me, and when I first got it I was rated at 18 mbit/sec, and was getting a solid 22. Not bad for phone wiring. Plus which AT&T gives me a 2 mbit/sec backchannel, which I find very useful (compared to the 30 or 40 kbit/sec up I got from Comcast, when I was on their 20 mbit/sec plan!) And it's consistent, usable bandwidth in both directions.
Re:400M ? (Score:3, Informative)
I've had Comcast for over 8 years in 2 different cities and have always maintained faster upload rates than that. By a number of multiples!!
Re:400M ? (Score:1, Informative)
Please describe a method for prioritizing acks using U-Verse with the ubiquitous and irreplaceable 2-wire "residential gateway" which is supplied.
Put a Linux box on your network with any IP in the same subnet as the other machines. It doesn't even need two NICs. Just turn on IP forwarding, make the default gateway on the Linux box the AT&T gateway and make the default gateway on everything else the Linux box. Then you can use egress throttling or whatever you want, because all traffic to the internet is going into and then back out of the Linux box.
Re:Don't forget the other factor. (Score:3, Informative)
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.
Re:400M ? (Score:3, Informative)
How is DMZ Plus broken? I turned off the wireless on my 2-wire and used DMZ plus to forward to my own router. Everything works perfectly, xbox, ps3, computers, bittorrent, etc.
I've been doing this for as long as I've had Uverse. I use two wireless routers to tunnel my network to the other side of my house rather than run cable. This allows me to have wired networks in each room (nice for file transfers) with wireless N connecting the two rooms on each end of the house. No way I could pull that off with the 2wire POS.