Some Perceived Problems with the Introduction of Terabit Network
Technologies.
This short paper attempts to highlight some potential problems
associated with the introduction of high speed networking -
specifically at the Terabit per second level. These problems are still
in the theoretical arena as practical Terabit networks are probably
still several weeks away from fabrication.
Introduction.
The primary problem when considering Terabit networks must be the
enormous speed that the packets on such networks will be traveling.
Naturally there are problems at the protocol level with very large
window sizes necessary for useful throughput, and enormous quantities
of data "in flight" at any one point. However, these problems
are encountered at the Gigabit level and are solvable in principle (by
appropriate window and packet size negotiation for instance).
The major problem that is perceived at such high speeds is that data
is now flowing at a significant fraction of the speed of light. This
brings into play a number of relativistic effects that must be taken
into account when designing such high speed networks.
Physical Considerations.
There are firstly a number of physical considerations that must be
taken into account. These are problems associated with any body
traveling close to the speed of light (c).
A large amount of energy is required to accelerate the
packets to the required velocity. However, the closer one approaches
c - the more of that energy is transformed into mass. Thus
packets will become heavier. A related problem is the slowing down of
packets, when they enter conventional lower speed Megabit networks. The
large amounts of energy that have gone into accelerating the packets
and giving them extra mass will be lost. This will require large heat
sinks. Cable fractures may also be explosive in these cases (which is
in keeping with the abbreviation TNT Terabit Network Technologies).
Alternatively, a special large coil of cable could be used to allow
the packets to naturally slow down.
Networks often need to be laid to fit the physical shapes
of buildings and other infrastructure. When any body traveling close
to c undergoes acceleration it tends to emit "breaking
radiation" or bremsstrahlung. This is particularly noticeable when
bodies have to undergo angular acceleration when turning corners.
Thus any bends in the cabling will have to be heavily shielded with
lead plates to stop the intense burst of high energy particles.
At high enough speeds, the curvature of the Earth may also prove a
significant loss of energy.
Whilst traveling at high speeds, the packets will undergo
time-dilation effects. Thus whilst two ends of a connection may agree
on a round-trip time for a packet, this may well be different to the
packets perceived RTT. The packets estimate of the RTT will be shorter
than the measured delay. Therefore if times are kept in the packet
this will lead to confusion.
When a body is traveling at high speeds, it tends to shrink in the
direction of the travel. This means that a packet taking 1400 bytes,
might actually take up 1300 bytes space on the network. This leads to
more capacity being available than might first be perceived. However
all routers must be able to handle packets at speed to stop them
suddenly growing. This leads to circuit switching being possibly a
better base technology.
A perhaps more serious problem is the case of collisions on a network
technology such as ethernet. The collision of two very high speed
packets could give rise to many spectacular effects, equivalent to
those seen in current particle accelerators. In par
Get some *really* tough balloons, forget the braking rockets, and with a good shot, the return trip is free as you bounce off Mars and back to Earth.
It would be the interplanetary equivalent of the bungee jump!
Is there some way this intrusion could be detected, and subverted into a honey pot trap?
Write a similar client that responds to the iamdemon and stuff, and then goes through the motions. Sends back believeable statistics and claims to be delivering lots and lots of addresses?
Anyone remember the SF story by, I think, Arthur C. Clarke, where one day, the telephone network after getting to a certain level of complexity became self aware?
Something to do with the number of interconnections between circuits becoming a reasonable fraction of the typical brains interconnections.
Anyway - it might not hurt to store up some good credit and be polite to your electrical outlets just in case.
... and we all shared a PDP11/70, and room full of TVI-912c terminals, and 80x24 was all you got.
If you could manage to get into the terminal room early you could grab a pair of tvi's next to each other and login twice, and be nearly twice as productive. On some desks you could actually get access to three terminals at once, heaven!
Let me refer the gentleman to the definitive source, the Hitch Hikes Guide to Galaxy, that explains exactly how big space really is.
Space is big. Really big. You just won't believe how vastly hugely mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space
The % hack routing is nothing compared to the old UUCP address style. Who can forget addresses like cuae2!gatech!mcnc!seismo!rutgers!princeton!a llegra !ulysses!faline!be llcore!mrevox!lcuxlm!whuts!hou xm!vertigo!roller
I doubt there will ever be an effective defense against spam, just like its predecessors we really haven't solved the overall issue of identifying it or making it unattractive to the sender.
Some random points to ponder: 1) What is spam, one mans spam is another mans ham, so there is NO universal measure (although some good approximations). 2) We've never managed to shut down the telemarketers cold calling. There not too much of a nuisance (depending on your definition of nuisance - why do they alsways call at meal times?) as they have to pay a significant cost per call, and automation is largely unsuccesful. 3) Junk mail is also costly to send, compared to email, and I still get lots of that.
I suspect the real answer, much like with junk mail, is to move house occasionally. It feels rather like giving in to me though.
Luckily this is easier with email than real life, but still a royal pain. Meanwhile bayesian filtering is the best I've found so far.
I too morn the passing of concorde. It may be old now, but it is still unmatched in wow factor.
Things must have improved since the late 60's in terms of aerodynamics, CAD, engine power etc etc.
There are few military jets built these days that can't achieve supersonic flight, and the latest can cruise above Mach 1 without afterburners.
So the technology must be there, so why is it so hard to make it commercial?
Maybe this is an opportunity. There are people who will pay for the convenience of fast travel, and in the 21st century we must be able to make something more efficient, quieter and more viable. Hell its been 40years since concorde was designed, someone tell me we've made progress since then.
Then again 30 years ago people were still walking on the moon.
I proposed this http://slashdot.org/~F4Codec/journal/ revolutionary format for basic data storage which includes embedded encryption, compression and many other extremely useful techniques many years ago. Do you think it has been not adopted and supressed by hardware vendors with their own agendas?
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Some Perceived Problems with the Introduction of Terabit Network Technologies.
This short paper attempts to highlight some potential problems associated with the introduction of high speed networking - specifically at the Terabit per second level. These problems are still in the theoretical arena as practical Terabit networks are probably still several weeks away from fabrication.
Introduction.
The primary problem when considering Terabit networks must be the enormous speed that the packets on such networks will be traveling. Naturally there are problems at the protocol level with very large window sizes necessary for useful throughput, and enormous quantities of data "in flight" at any one point. However, these problems are encountered at the Gigabit level and are solvable in principle (by appropriate window and packet size negotiation for instance).
The major problem that is perceived at such high speeds is that data is now flowing at a significant fraction of the speed of light. This brings into play a number of relativistic effects that must be taken into account when designing such high speed networks.
Physical Considerations.
There are firstly a number of physical considerations that must be taken into account. These are problems associated with any body traveling close to the speed of light (c).
A perhaps more serious problem is the case of collisions on a network technology such as ethernet. The collision of two very high speed packets could give rise to many spectacular effects, equivalent to those seen in current particle accelerators. In par
This reminds me of the Arthur C. Clarke story, Earthlight. The battle was set on the moon, which helps considerably with projectile weapons.
The weapon used in this case was a large glob of molten steel, fired using extremely large electro-magnets to launch and guide the "projectile".
The image he paints of spearing a space ship, like a pinned butterfly has stayed me for a long while.
... A beowulf cluster of those - does 2 make for a cluster, and did they bring a big enough piece of cable, or do you suppose Wifi would work.
What would Beagle have run had it run?
Get some *really* tough balloons, forget the braking rockets, and with a good shot, the return trip is free as you bounce off Mars and back to Earth. It would be the interplanetary equivalent of the bungee jump!
Is there some way this intrusion could be detected, and subverted into a honey pot trap? Write a similar client that responds to the iamdemon and stuff, and then goes through the motions. Sends back believeable statistics and claims to be delivering lots and lots of addresses?
Something to do with the number of interconnections between circuits becoming a reasonable fraction of the typical brains interconnections.
Anyway - it might not hurt to store up some good credit and be polite to your electrical outlets just in case.
If you could manage to get into the terminal room early you could grab a pair of tvi's next to each other and login twice, and be nearly twice as productive. On some desks you could actually get access to three terminals at once, heaven!
So why does two monitors beat two separate PC's?
Space is big. Really big. You just won't believe how vastly hugely mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space
Not only is it not just a matter of life and death, but football is an integral part of the universe...
The % hack routing is nothing compared to the old UUCP address style.a llegra !ulysses!faline!beu xm!vertigo!roller
Who can forget addresses like
cuae2!gatech!mcnc!seismo!rutgers!princeton!
llcore!mrevox!lcuxlm!whuts!ho
Ahh - nostalgia!
I doubt there will ever be an effective defense against spam, just like its predecessors we really haven't solved the overall issue of identifying it or making it unattractive to the sender.
Some random points to ponder:
1) What is spam, one mans spam is another mans ham, so there is NO universal measure (although some good approximations).
2) We've never managed to shut down the telemarketers cold calling. There not too much of a nuisance (depending on your definition of nuisance - why do they alsways call at meal times?) as they have to pay a significant cost per call, and automation is largely unsuccesful.
3) Junk mail is also costly to send, compared to email, and I still get lots of that.
I suspect the real answer, much like with junk mail, is to move house occasionally. It feels rather like giving in to me though.
Luckily this is easier with email than real life, but still a royal pain. Meanwhile bayesian filtering is the best I've found so far.
Trouble is, I can't see how you get a handrail into these multiple strip senarios, so your chance of causing a pile up increases dramatically.
Say, whats the bandwidth of one of these if you can stack boxes of DVD-RW on one end and take them off the other.
Julian.
Besides its not just the sizes, its being able to route on them that matters. However I agree for now we have plenty of space in IPv6.
Julian.
if only the computer industry would adopt my schemefor data encoding, all this crypto stuff would become irrelevant.
Things must have improved since the late 60's in terms of aerodynamics, CAD, engine power etc etc. There are few military jets built these days that can't achieve supersonic flight, and the latest can cruise above Mach 1 without afterburners.
So the technology must be there, so why is it so hard to make it commercial?
Maybe this is an opportunity. There are people who will pay for the convenience of fast travel, and in the 21st century we must be able to make something more efficient, quieter and more viable. Hell its been 40years since concorde was designed, someone tell me we've made progress since then.
Then again 30 years ago people were still walking on the moon.
Maybe we've all lost our spirit of adventure?
Julian.