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Researchers Transmit Optical Data at 16.4 Tbps 2550km
Stony Stevenson writes "The goal of 100 Gbps Ethernet transmission is closer to reality with the announcement Wednesday that Alcatel-Lucent researchers have recorded an optical transmission record along with three photonic integrated circuits. Carried out by researchers in Bell Labs in Villarceaux, France, the successful transmission of 16.4 Tbps of optical data over 2,550 km was assisted by Alcatel's Thales' III-V Lab and Kylia, an optical solution company. The researchers utilized 164 wavelength-division multiplexed channels modulated at 100-Gbps in the effort."
What's that in Library-of-Congresses per fortnight?
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
Would this qualify as 11?
That's a lot of cows.</walken>
Carousel is a lie!
That's just BURST throughput. Depending on factors like time of day, how many other users there are, and environmental conditions, throughput may drop as low as 33kbps. And we do NOT filter bittorrent.
Just check your TOS agreement. It's all right there.
In other news: American telcos wonder how French providers are able to afford research and development without additional funding from a tiered billing billing scheme that is needed to advance the science in the United States.
"164 wavelength-division multiplexed channels modulated at..."
how very Star Trek of them.
You feel sleepy. Close your eyes. The opinions stated above are yours. You cannot imagine why you ever felt otherwise.
Tbps speed, and over 100 Gbps. Something is wrong here.
No matter how much speed they create, they will still be subject to the Law of Diminishing Porn Returns, which states:
For download rate n, my demand for new porn will require me to download at a rate of n+1.
Surely if an ISP adopted this, they'd have people signing up left right and centre. Wouldn't it be awfully attractive to their target audience?
This is the reason 100gpbs isn't being considered for lan use. It just isn't feasible at this point.
Stick a thousand machines on each end, and you'll understand why 100Gbps is needed.
The problem has never been the glass! There is absolute craploads of dark fiber just about everywhere. Last time I saw stats it was something like less than 1/3rd of installed fiber was lit up. It's the uber expensive routing equipment needed to keep up with the flood of data that's the expensive part.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
If you really need greater than 10Gbps then go with Infiniband as you can get 12x HCA's that will do 24GBps (48Gbps full duplex). But if you're paying $50 for 10Gbps ethernet you're not getting offloading and your CPU's are probably swamped of your TCP/IP stack is the problem. I would suggest getting a pair of offloading 10Gbps cards and seeing if you don't see a huge improvement.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
I'm running Linux on a Playstation3 with SPU video drivers in its Cell uP that can run at over 150GFLOPS. Since the PS3 has only 512MB RAM, it needs to be fed by the LAN and just buffer the LAN in its RAM. Even if SATA drives are delivering only 1.2Gbps, there's no reason I can't have multiple parallel drives on independent servers (if a single server's IO isn't fast enough for multiple SATA at full bore) on my SAN delivering multiple streams through my switch all to my Playstation. Now, the PS3's 1Gb-e is as hardwired to it as is its 512MB RAM, but the point is that there are already machines that can use that bandwidth. The total bandwidth doesn't have to reach 100Gbps, but only exceed 10Gbps, to require faster than 10G-e, which only 8-10 SATA drives in parallel could do today.
So the bottleneck is 10G-e. There are already supercomputer clusters using multiple parallel Cells, so I'm disappointed that they're not already widening the pipe.
--
make install -not war
There is another problem, and is actually the bottleneck of transmitting packets at high rates.
It doesn't really matters (yet, and considering Ethernet technology) if the BW of the fiber is a zillion Petabits/sec.
The problem is now at 1Gbps and 10Gbps in Ethernet technology, and is because the processor overloads with the amount of hardware interrupts. The processors that are general purpose have to waste too many clock cycles processing that much interrupts, the processors nowadays are superscalar [ http://en.wikipedia.org/wiki/Superscalar ]and every time the processor have to change the context (to attend an interrupt) has to do lots of things like unloading the registers, saving the context, loading the registers of the new process, and has to drop something out of the pipeline [ http://en.wikipedia.org/wiki/Pipeline_(computing) ] loosing performance.
Ethernet tech has a huge latency [ http://en.wikipedia.org/wiki/Latency_(engineering) ] and a stack that makes processing not so easy (if you look at te code of a linux network device driver it handles pretty much everything including writing the mac address that is only copied when the driver initialize).
That is why there are some relative new things (NAPI in Linux) that try to make lessen the overload, there are new network devices that handle layer 2 and 3 (or at least parts of those, for example, is used to be handled the checksum algorithm) to avoid doing it in the processor. There are some white papers (one from intel, another from NetXen, I'm sorry I don't have the links now) that explain the problem and some approach to a possible solution.
Yes, I know, there is something I have not said, and is that the main switches or routers have to deal with that and have hardware specially designed to do heavy network packet processing, and that is the point, the network cards will have to do that (and are already starting to), neither is an easy job for hardware designers, nor for the market, is easier and cheaper to have a machine that you can change the behaviour only changing the firmware or changing settings from a program (routers have an operating system, and lots of those are a general purpose microprocessor with a linux kernel and a web server to configure it, for example home routers).
There is much to say yet in this field.
"Everyone" is waiting for either 40Gbit/s or 100Gbit/s Ethernet.
The first one is what server-people push (they claim they do not need more, that's why 40Gbit/s was put into Ethernet standard),
while network people want full 100 Gbit/s.
> But what about all the LAN vendors, which have a real market for 100Gbps
They don't.
There seems to be market either for 40Gbit/s in LAN/local connections or for 100Gbit/s for core/long haul. At least judging but what happened with high-speed ethernet standard.
Senator Stevens? Is that you?
Interrupt loads can be greatly reduced by switching to a polling-driven architecture. See FreeBSD.
Mea navis aericumbens anguillis abundat
>Interrupt loads can be greatly reduced by switching to a polling-driven architecture. See FreeBSD.
New API (NAPI) takes a mixed approach, read: [ http://en.wikipedia.org/wiki/New_API ], and for more information: [ http://www.linux-foundation.org/en/Net:NAPI ].