I'm not a Cisco fan, but you're not factoring in the cost of Cisco R&D, testing, documentation, software development, which all adds up to billions of dollars for them. Most of it is probably not very efficient any more due to their size, which is why younger companies like Juniper or Polycom or Cyan can offer more for less, depending on the type of equipment you're after. Still, it's not like Cisco could sell their products for 10% over the component cost and not immediately start hemorrhaging money.
It doesn't have to run a TCP/IP stack and phone home, it could be as simple as an undocumented instruction that would branch to an arbitrary memory location, allowing anyone who knows about it to write exploits against the system.
A repeater is different from an amplifier. A repeater receives the signal, cleans it up in the electrical domain, and retransmits it. This has to be done channel by channel so in this experiment they would need 155 of them along with the associated mux/demux WDM gear to transpond all channels. An amplifier on the other hand amplifies everything between about 1520 and 1610 nanometers, all in the optical domain. All undersea cables have amplifiers in 'festoons' which are enclosures that sit on the ocean floor.
Laying another cable is crushingly expensive, but you're right this technique is still so vastly inferior to WDM that nobody is seriously pursuing it outside of science projects.
What you're describing would be WDM, and this is OAM or Spatial Multiplexing depending on who you talk to.
Your eyes and brain work that way. Other sensors don't. A 'red bit' plus a 'blue bit' will not trigger a purple sensor.
That's not really true, photodiodes and avalanche photodiodes are not channel specific. I can connect a transmit from a 1560.61 to a RX of a 1558.98 and they will work just fine. Most are wide-band and will happily receive anything from 1250 to 1650 nanometers. If I mix those wavelengths with a combiner and send them into a receiver, I'll get a loss of frame because the signals conflict. The channels have to be 'demulitplexed' at the far end with some kind of WSS, AWG, FBG or other optical device.
You've hit on the real reason nobody is interested in OAM/Spatial mutliplexing. Depending on the vendor, we can light 80 to 160 channels of DWDM today on a pair of fibers, and go for thousands of kilometers in a well planned system.
Are you inventing the word 'consistant' as well? Is that a synonym of cromulent? I submit that if I'm going to be condescending, I should be 'Niles Crane' condescending.
Most of the area this canal would be built through is jungle with no roads anyway, there would only be a need for a few bridges on the east coast and a few bridges on the west coast.
They've really never gone away, they're just going away at the consumer level. At the transport and wholesale level, circuits are the past, present and future. Openflow is a good example at the Datacenter and maybe soon the carrier aggregation layer. G.709 OTN is a good example at the large bandwidth long-haul layer.
The big deal here is that there are a lot of fiber types that we couldn't go beyond 2.5G on due to effects like four wave mixing, chromatic dispersion, polarization mode dispersion. Those fibers have been sitting idle, and now have value again due to the fundamental differences in how the 'coherent' optics are modulated. In many cases that's going to mean millions of dollars of construction can be avoided because existing fiber can be used again.
I'll admit I skipped the last couple of sentences in the post, mostly out of pain. Now I see you're in the academic world, which explains a lot. Sorry.
It's heartbreaking to see how little the average slashdotter actually knows about technology when they start talking about my field.
First, optical amplifiers are not 're-encoders' which isn't a real term anyway, the closest thing to what you mean is a 'transponder' and those are only used at end-points. The two types of optical amplifiers are Erbium Doped Fiber Amplifiers and Raman effect amplifiers. They do not receive and retransmit, they literally add photons of the exact same wavelength and polarity as the original signal, with no interruption.
This article is ultimately about how the new coherent DSP enabled 100G and beyond fiber optic gear is actually much more tolerant of noise, chromatic dispersion, and polarization mode dispersion than the previous 10G on-off keyed gear. That allows carriers to go back and use fiber types that we used years ago that are obsolete, such as Zero Dispersion Shifted fiber.
Yes, technology always offers improvements, but this is not an incremental improvement. This is a huge leap forward.
There is no correct way to pluralize Texas, there can be only one Texas. Anyway, just because Australia or Alaska or Siberia are larger, doesn't mean Texas still isn't a big place. You can drive from Beaumont, Texas to Los Angeles and by the time you're halfway there, you're still in Texas.
That's probably not the case. It seems like these days a presidential candidate is chosen for broad(ish) appeal, but the VP is chosen to be a party hard liner to galvanize the faithful voting blocks and keep the party legislators in line. See Biden, Cheney, Gore. I think Palin was a calculated choice to try to get a group of people, Tea Party, to vote Republican instead of Libertarian.
My chromebook is faster, easier to use, has better battery life, and has a much better screen than my smart phone or my kindle fire. Also, both of those have to be rebooted occasionally. Not sure if I've ever done anything but put the Chromebook to sleep. It really was a smart purchase.
You are overthinking it. If I wanted to tap someone's network, I'd find a splice case in the middle of nowhere and splice in a 90/10 splitter during some unrelated outage so it wouldn't be noticed. To the victim it would just look like a relatively poor splice on their OTDR readings.
Slashdot Mirror
Isn't picking and choosing which parts of the constitution to support the reason we dislike the NSA so much in the first place?
It's the modern era progression of making the Doctor younger and more of a wimp, until eventually he is a zygote time lord.
Krebs is German for 'Cancer', but in a pinch can also mean 'Crab'
Krebs is german for Crabs. Cancer is Latin for Crab. There's no pinch needed.
I'm not a Cisco fan, but you're not factoring in the cost of Cisco R&D, testing, documentation, software development, which all adds up to billions of dollars for them. Most of it is probably not very efficient any more due to their size, which is why younger companies like Juniper or Polycom or Cyan can offer more for less, depending on the type of equipment you're after. Still, it's not like Cisco could sell their products for 10% over the component cost and not immediately start hemorrhaging money.
It doesn't have to run a TCP/IP stack and phone home, it could be as simple as an undocumented instruction that would branch to an arbitrary memory location, allowing anyone who knows about it to write exploits against the system.
A repeater is different from an amplifier. A repeater receives the signal, cleans it up in the electrical domain, and retransmits it. This has to be done channel by channel so in this experiment they would need 155 of them along with the associated mux/demux WDM gear to transpond all channels. An amplifier on the other hand amplifies everything between about 1520 and 1610 nanometers, all in the optical domain. All undersea cables have amplifiers in 'festoons' which are enclosures that sit on the ocean floor.
No it isn't. Latency through a switch is measured in microseconds.
Wrong, this still requires amplifiers every 100km, just like today.
What do you think DWDM is?
Laying another cable is crushingly expensive, but you're right this technique is still so vastly inferior to WDM that nobody is seriously pursuing it outside of science projects.
What you're describing would be WDM, and this is OAM or Spatial Multiplexing depending on who you talk to.
Your eyes and brain work that way. Other sensors don't. A 'red bit' plus a 'blue bit' will not trigger a purple sensor.
That's not really true, photodiodes and avalanche photodiodes are not channel specific. I can connect a transmit from a 1560.61 to a RX of a 1558.98 and they will work just fine. Most are wide-band and will happily receive anything from 1250 to 1650 nanometers.
If I mix those wavelengths with a combiner and send them into a receiver, I'll get a loss of frame because the signals conflict. The channels have to be 'demulitplexed' at the far end with some kind of WSS, AWG, FBG or other optical device.
You've hit on the real reason nobody is interested in OAM/Spatial mutliplexing. Depending on the vendor, we can light 80 to 160 channels of DWDM today on a pair of fibers, and go for thousands of kilometers in a well planned system.
Are you inventing the word 'consistant' as well? Is that a synonym of cromulent? I submit that if I'm going to be condescending, I should be 'Niles Crane' condescending.
This isn't coining a new phrase, it's not understanding an existing one. Being wrong is not a matter of scale.
Most of the area this canal would be built through is jungle with no roads anyway, there would only be a need for a few bridges on the east coast and a few bridges on the west coast.
They've really never gone away, they're just going away at the consumer level. At the transport and wholesale level, circuits are the past, present and future. Openflow is a good example at the Datacenter and maybe soon the carrier aggregation layer. G.709 OTN is a good example at the large bandwidth long-haul layer.
T1s and T3s are also plesiosysnchronous! But yea, the OP definitely got synchronous and symmetrical confused.
The big deal here is that there are a lot of fiber types that we couldn't go beyond 2.5G on due to effects like four wave mixing, chromatic dispersion, polarization mode dispersion. Those fibers have been sitting idle, and now have value again due to the fundamental differences in how the 'coherent' optics are modulated. In many cases that's going to mean millions of dollars of construction can be avoided because existing fiber can be used again.
I'll admit I skipped the last couple of sentences in the post, mostly out of pain. Now I see you're in the academic world, which explains a lot. Sorry.
It's heartbreaking to see how little the average slashdotter actually knows about technology when they start talking about my field.
First, optical amplifiers are not 're-encoders' which isn't a real term anyway, the closest thing to what you mean is a 'transponder' and those are only used at end-points. The two types of optical amplifiers are Erbium Doped Fiber Amplifiers and Raman effect amplifiers. They do not receive and retransmit, they literally add photons of the exact same wavelength and polarity as the original signal, with no interruption.
This article is ultimately about how the new coherent DSP enabled 100G and beyond fiber optic gear is actually much more tolerant of noise, chromatic dispersion, and polarization mode dispersion than the previous 10G on-off keyed gear. That allows carriers to go back and use fiber types that we used years ago that are obsolete, such as Zero Dispersion Shifted fiber.
Yes, technology always offers improvements, but this is not an incremental improvement. This is a huge leap forward.
His point is that crack smoking doesn't automatically make one lose weight. Nice rebuttal.
There is no correct way to pluralize Texas, there can be only one Texas. Anyway, just because Australia or Alaska or Siberia are larger, doesn't mean Texas still isn't a big place. You can drive from Beaumont, Texas to Los Angeles and by the time you're halfway there, you're still in Texas.
That's probably not the case. It seems like these days a presidential candidate is chosen for broad(ish) appeal, but the VP is chosen to be a party hard liner to galvanize the faithful voting blocks and keep the party legislators in line. See Biden, Cheney, Gore. I think Palin was a calculated choice to try to get a group of people, Tea Party, to vote Republican instead of Libertarian.
My chromebook is faster, easier to use, has better battery life, and has a much better screen than my smart phone or my kindle fire. Also, both of those have to be rebooted occasionally. Not sure if I've ever done anything but put the Chromebook to sleep. It really was a smart purchase.
You are overthinking it. If I wanted to tap someone's network, I'd find a splice case in the middle of nowhere and splice in a 90/10 splitter during some unrelated outage so it wouldn't be noticed. To the victim it would just look like a relatively poor splice on their OTDR readings.