If you think you can offload OFDM encoding and decoding to the CPU, think about the kind of bus bandwidth you'd need to do it. PCI runs 64 bits at 66 MHz, best case. That's a bandwidth of 512MBps. Suppose you could specify a single chip with one bit on the bus; then you could live with a chipping rate of 4Gcps. Given the 10.4dB processing gain, you're _bus_ bandwidth capped at 372Mbps, and that's with nothing else running.
Let's get a little more realistic: currently PCI runs at 32 bits 33MHz in your desktop machine. That means that if your computer is ONLY sending chips over the bus, you can't even do turbo mode (dual channel) 802.11a. (93Mbps 108Mbps).
Now let's make things worse. To make it completely frequency independant, we assume you only need to code the ISM bands: 26MHz wide at 915MHz, 83.5MHz wide at 2.4GHz, and 125MHz wide at 5.8GHz. That's a total of 234.5 MHz of bandwidth. Now you've got to cover about 4-8 times as much ground as the simple 802.11a situation, and you're still dependant on the ASIC translating your chips into OFDM modulated stuff.
I'm not enough the physical layer guy to tell you how much data you need to pass across the bus to get OFDM to work without the hardware knowing anything about it...
Lots of the 802.11i stuff is aimed at being back-compatible to existing WEP hardware. It's hard to make things like QoS do that though.
Winmodems can work because the bandwidth of a phone line is so small. With the size of frequency bands in the ISM band, you can't do that anymore.
By that logic, it'd be even cheaper to move to Russia, where you could pay 70k rubles = $2255.88 USD, and save a grand total of $67,744.12. The employee would be totally happy, since the cost of living in Russia is so low, and the nature there is beautiful too.
Incidentally, in Canada, how much do you pay for gas? $1? That sounds reasonable. What? It's per LITRE?
Furthermore, I simply don't buy that Canadian cost of living is 59.2% less, especially after all those taxes.
Admittedly, with socialized health care, companies might save a bit on fringe, but their employees will pay it directly in GST and PST.
This is an interesting point. Just having read the abstract, it seems that the paper proves this in a way similar to the halting problem proof: I'm going to build this one thing that you can't obfuscate.
The real question is whether or not there is a class of programs that can be obfuscated.
I really wonder about cloakware; it seems like a kernel debugger could find the key that goes into code that looks like AES, or even profile the cache behavior of a normal AES algorithm, and try to detect the running of AES in the actual program.
However, I wouldn't mark this particular moderator down. Your post was a list of complaints about what other people are doing to solve a real problem with no solution of your own to offer or any reason why its not a problem. Personally I wouldn't mark it as a troll but I think it's borderline.
Does criticizing a solution mean that I have to try to solve it myself? If I said "I want to go to the moon, I'll buy a couple D rockets from the hobby rocket shop," would someone be mistaken to say "that'll never work" without providing a solution? Would a "that can't work, moron" response be a troll, or even justified as one?
I'm just bothered by the general "rah rah rah IPv6" crowd, plus the "it'll never happen because of evil M$" crowd. There are real, technical issues with IPv6. There are real, nice benefits of IPv6. One of the places the IETF really messed up, though, is the increase of address space. Sure, it's not a big deal on modems, since compression will help a lot (IPv6 headers compress much better than IPv4 headers).
But the big thing you're leaving out of the picture here is the mobile/wireless explosion that has happened of late. Yes, it's great that my UMTS phone will have IPv6 and actually be addressable. Hoorah. But all those extra bits have to go over the (sparse and expensive) air.
Worse yet is the problem with ad hoc networks. People are putting router IDs (RIDs) in their routing protocols, so they can squeeze a 128-bit header into 32 bits. Problem is, you need to pick unique router IDs, and you need to advertise the correct associations. This is a major pain. You can't just waste the bits, because they're going over potentially slow links, every bit transmitted costs battery power at all receiving nodes, and increases congestion in that area of the network.
A major advantage of 128 bit addresses is that it makes things like SUCV (statically unique cryptographically verifiable) addresses possible. But that's only necessary (at least now) because the IPsec WG screwed over Mobile IP's IPv6 authentication scheme (with certificates for each address).
If you accept that the earth's population will stay under 2^40 (1099 billion) for the forseeable future, then each person will have 2^24 addresses. Even allowing for inefficiencies due to things like CIDR, each person will still have over 16000 addresses (16 million with perfect efficiency). I just don't think we'd ever run out. Also, considering the address allocation scheme of IPv6, it's not clear that a better allocation scheme for 64 bit SIP wouldn't last longer. 64 bit interface indicies? Please. I'm not going to have 2^64 interfaces anytime soon.
See, this is what you should have put in the original post.
Why, do I need to quote Steve Deering to carry enough weight to criticize IPv6? I pointed out in my original posts the disadvantages of the IPv6 addressing scheme.
Interesting that none of the major issues with IPv6 are addressed by an idiot moderator who doesn't know what to do with his/her moderation points. Guys, when you get moderation points, only moderate the stories you're an expert on. Even the people who go to the "universal adoption of IPv6" Scotch BOFs at the IETF would agree with many of these points. In particular, Steve Deering, the author of SIP, which later merged with a number of other things to become IPv6, would agree that 128 bit IP addresses is overkill, and SIP had only 64 bit addresses originally.
CmdrTaco: if you let moderators do stupid things like this (and yes, there are more stupid moderators than smart ones), you're going to alienate all your clueful posters.
Re:I guess that kid hit puberty early...
on
iWarez
·
· Score: 2
So keep it in your shoes.
This sounds a lot like how the airports are enforcing "security:" respond to exploited threat models, and avoid publicising the known ones.
Honest men have nothing to hide. I don't think shareholders would see an email shredder as good news. Sure, you've reduced "liability," but you could further reduce it by having a higher set of moral codes.
xenocide2, what's your social security number, mother's maiden name, and which credit cards do you carry? Can you give me their numbers, or do you have something to hide? How about your home address, and phone number? Passwords to computer accounts? A list of all your purchases, including those you made in cash, over the last year? A list of all the web pages you've hit, ever? Your income history, and tax returns, for the last 7 years (you know the IRS wants you to keep those for that long, right?) All school transcripts?
Why don't you post those all to slashdot, as proof that you're an honest man, and that you're following your set of "moral codes."
GPS uses two channels for positioning (L1 @1575.42 MHz and L2 @1227.60 MHz) and one for nuclear test detection (L3 @1381.05 MHz), none of which are anywhere close to 3GHz.
So, why do people who use GPS care? Are they worried about accidental emission in the 1.2-1.6GHz band?
I'm amused by the moderation here. You spend 4 years of your life doing cutting edge research in an area, get published at the top conferences pretty much at will, you understand the protocols and problems in sufficient detail to respond to posts without a reference. You see a story posted referring to a website written by a few morons at a no-name state school who have security tips far below the best current practice, and you point out that such tips are bogus, but they're trying to sell consulting services.
Point that out, get moderated as Troll and Flamebait. I've gotta start metamoderating.
Not that it matters, since I've got karma to burn, but I'd obviously like my posts to get read...
*sigh* Why is it that the one area we _can_ have near-military quality security, people insist on "make my installation marginally harder to crack than my neighbor's"? Can you imagine if the US government said "I agree that the current security of Los Alamos leaves much to be desired. But nothing can keep out a determined hacker."
If you give heavy weapons to your "determined hacker," I agree. But if you're talking about some moron hiding in the bushes with a laptop and a yagi, then I think I can design a system to keep them out, using commercial off-the-shelf (and possibly free) software.
The physical analogy breaks down, since clearly even the government has problems breaking the encryption easily accessable to civilians, while it has no such trouble breaking into civilian buildings (excluding Waco). If we all had access to tanks, antiaircraft missles, and nukes, I probably could keep you a good distance from my home =)
Using WEP is the same as remembering to lock the doors of your hose. People can still pick the locks, but they have to be determined to get in.
Not really; it's like closing the door. I'd hardly call script kiddies "really determined," but any of them can run airsnort.
Turn off SSID broadcast and obscure it
But when I hear someone register, then I can get in. Kinda like plaintext password authentication.
Why should we apply patches to Apache or IIS? What's it gonna do?
While I agree it's a good idea, it's not going to keep the baddies out of the network. For example, the latest firmware for Lucent WaveLAN automatically generates a somewhat random IV, which prevents some of the IV collision attacks documented in the literature. It doesn't stop the fundamental insecurity of WEP, though, and giving people a false sense of security, rather than using a real solution like firewalling the wireless network and only allowing users in through tunneling (such as VPN or SSH tunneling), may be quite harmful.
None of them are particularly strong. That's like saying "Security Tips for your home:"
Close your door when you're out
Add a fake lock to your door
Paint your house black so burglers can't find it
Paint doors on your house so they might bang their heads against a wall
They are so far off from the best current practices that it's quite pathetic. Anyone who gives a list of security tips like that is unlikely to get my business as an burgler alarm system vendor.
And if I were willing to code up a specialized OS to run my huge (single) program, I wouldn't be in user mode, now would I. This is a tradeoff I've actually considered, since Itaniums are somewhat pricey. Of course, typically your time is more expensive than a shiney new Itanium, even if the latter costs $100k.
Incidentally, I considered whether or not to make the 4GB per process in user space argument, but someone would doubtless raise the large memory extensions to Linux. In any case, since the hardware supports 64GB, you could use 60GB as process-managed swap and know that random access in that area is legal.
As it stands, RAM is so cheap that if you needed 64GB RAM, you could just buy it without having it raise the price of your box too much. It's stupid for Intel to keep cranking out 32-bit processors, and hopefully they'll get Hammered for their trouble and have to bring out Yamhill.
There are four multihop routing protocols currently under consideration at the IETF MANET WG.
Who cares about GHz...
on
Intel's Big Chip
·
· Score: 5, Insightful
... if you can't run the apps.
Intel x86 is restricted to 48-bit addressing (with segment registers), and practically 64GB with modern OSes. (http://linux-mm.org/)
If I want more than 64GB of addressable physical memory (which I do for some apps), then who cares if you can give me a 32-bit x86 running at 900GHz, it's not going to do diddly squat for me, since _going over the PCI bus_ for swap is going to kill me vs a 1.6GHz 64-bit processor. And since you need to go over the PCI bus just to get to a pseudo-disk stuffed with RAM, that solution is still bogus.
I see your point that this isn't what Joe Blow's gonna put on his desk. But the improved address space is definately a big win, and that's assuming that they can't ramp up the clock speed in a hurry.
I've had a 3870 (top-of-the-line iPaq) for about a week. I use a Vx as my regular PDA. The 3870 is kinda neat, with its color screen,
but it's too bulky to carry everywhere.
I could see using a 3870 as a laptop replacement with an 802.11 card. As a PDA with WinCE, its calendar
sucks compared to DateBk4, it doesn't have travel management software like TravelTracker, the lack of
something like MidCapsHack on the block recognizer makes it somewhat less useful, things run super-slow,
and there's no free SSH client. Oh yeah, and the dev environment is a pain in the tush.
The Linux support for the 3870 is coming slowly, but it's not going to replace my datebook. There isn't a decent
calendaring program yet for iPaq linux, and that's a necessary prerequisite to being a PDA. Not to mention the
total lack of an address book. And don't get me started on power management issues...
Obviously, there's a reason I have an iPaq, but it sure as heck isn't because I think it's a PDA. If I lost my Vx, I'd
get a PalmOS box, even though switching over to the iPaq would be free.
Good for you if you've found a way to carry the brick of a PDA that the iPaq is without having it drag your pants off. I'm sticking with my Palm for the apps, speed, battery life, size, and weight.
How about Teledesic? They want to launch a 288-satellite constellation by 2005.
According to their FAQ, Teledesic's primary investors are telecommunications pioneer Craig McCaw, Microsoft Chairman Bill Gates, Motorola, Saudi Prince Alwaleed Bin Talal, Abu Dhabi Investment Company and Boeing. Sounds like there's enough money there to sink an aircraft carrier...
No antiskip? What's that 10sec/40sec ESP switch on the back? I drove from Nashville to Houston with one of these guys and it never skipped a single time, even in the 10sec mode. I also used it on about 9 continuous days (216 hours) of flying time (~100k mi) and I've never had it skip, not even in the worst of turbulence. (Obviously, it wasn't ever on for landing, but we lost an engine once and experienced some pretty bad vibration from that).
I wouldn't train for a marathon with an MP3 CD player, because it definately does have moving parts, but the solid state stuff would be just fine.
I've had a 3870 for about a week. I use a Vx as my regular PDA. The 3870 is kinda neat, with its color screen, but it's too bulky to carry everywhere.
I could see using a 3870 as a laptop replacement with an 802.11 card. As a PDA with WinCE, its calendar sucks compared to DateBk4, it doesn't have travel management software like TravelTracker, the lack of something like MidCapsHack on the block recognizer makes it somewhat less useful, things run super-slow, and there's no free SSH client. Oh yeah, and the dev environment is a pain in the tush.
The Linux support for the 3870 is coming slowly, but it's not going to replace my datebook. There isn't a decent calendaring program yet for iPaq linux, and that's a necessary prerequisite to being a PDA. Not to mention the total lack of an address book. And don't get me started on power management issues...
Obviously, there's a reason I have an iPaq, but it sure as heck isn't because I think it's a PDA. If I lost my Vx, I'd get a PalmOS box, even though switching over to the iPaq would be free.
Slashdot Mirror
eqteam, thanks for the sanity =)
If you think you can offload OFDM encoding and decoding to the CPU, think about the kind of bus bandwidth you'd need to do it. PCI runs 64 bits at 66 MHz, best case. That's a bandwidth of 512MBps. Suppose you could specify a single chip with one bit on the bus; then you could live with a chipping rate of 4Gcps. Given the 10.4dB processing gain, you're _bus_ bandwidth capped at 372Mbps, and that's with nothing else running.
Let's get a little more realistic: currently PCI runs at 32 bits 33MHz in your desktop machine. That means that if your computer is ONLY sending chips over the bus, you can't even do turbo mode (dual channel) 802.11a. (93Mbps 108Mbps).
Now let's make things worse. To make it completely frequency independant, we assume you only need to code the ISM bands: 26MHz wide at 915MHz, 83.5MHz wide at 2.4GHz, and 125MHz wide at 5.8GHz. That's a total of 234.5 MHz of bandwidth. Now you've got to cover about 4-8 times as much ground as the simple 802.11a situation, and you're still dependant on the ASIC translating your chips into OFDM modulated stuff.
I'm not enough the physical layer guy to tell you how much data you need to pass across the bus to get OFDM to work without the hardware knowing anything about it...
Lots of the 802.11i stuff is aimed at being back-compatible to existing WEP hardware. It's hard to make things like QoS do that though.
Winmodems can work because the bandwidth of a phone line is so small. With the size of frequency bands in the ISM band, you can't do that anymore.
By that logic, it'd be even cheaper to move to Russia, where you could pay 70k rubles = $2255.88 USD, and save a grand total of $67,744.12. The employee would be totally happy, since the cost of living in Russia is so low, and the nature there is beautiful too.
Incidentally, in Canada, how much do you pay for gas? $1? That sounds reasonable. What? It's per LITRE?
Furthermore, I simply don't buy that Canadian cost of living is 59.2% less, especially after all those taxes.
Admittedly, with socialized health care, companies might save a bit on fringe, but their employees will pay it directly in GST and PST.
This is an interesting point. Just having read the abstract, it seems that the paper proves this in a way similar to the halting problem proof: I'm going to build this one thing that you can't obfuscate.
The real question is whether or not there is a class of programs that can be obfuscated.
I really wonder about cloakware; it seems like a kernel debugger could find the key that goes into code that looks like AES, or even profile the cache behavior of a normal AES algorithm, and try to detect the running of AES in the actual program.
Does criticizing a solution mean that I have to try to solve it myself? If I said "I want to go to the moon, I'll buy a couple D rockets from the hobby rocket shop," would someone be mistaken to say "that'll never work" without providing a solution? Would a "that can't work, moron" response be a troll, or even justified as one?
I'm just bothered by the general "rah rah rah IPv6" crowd, plus the "it'll never happen because of evil M$" crowd. There are real, technical issues with IPv6. There are real, nice benefits of IPv6. One of the places the IETF really messed up, though, is the increase of address space. Sure, it's not a big deal on modems, since compression will help a lot (IPv6 headers compress much better than IPv4 headers).
But the big thing you're leaving out of the picture here is the mobile/wireless explosion that has happened of late. Yes, it's great that my UMTS phone will have IPv6 and actually be addressable. Hoorah. But all those extra bits have to go over the (sparse and expensive) air.
Worse yet is the problem with ad hoc networks. People are putting router IDs (RIDs) in their routing protocols, so they can squeeze a 128-bit header into 32 bits. Problem is, you need to pick unique router IDs, and you need to advertise the correct associations. This is a major pain. You can't just waste the bits, because they're going over potentially slow links, every bit transmitted costs battery power at all receiving nodes, and increases congestion in that area of the network.
A major advantage of 128 bit addresses is that it makes things like SUCV (statically unique cryptographically verifiable) addresses possible. But that's only necessary (at least now) because the IPsec WG screwed over Mobile IP's IPv6 authentication scheme (with certificates for each address).
If you accept that the earth's population will stay under 2^40 (1099 billion) for the forseeable future, then each person will have 2^24 addresses. Even allowing for inefficiencies due to things like CIDR, each person will still have over 16000 addresses (16 million with perfect efficiency). I just don't think we'd ever run out. Also, considering the address allocation scheme of IPv6, it's not clear that a better allocation scheme for 64 bit SIP wouldn't last longer. 64 bit interface indicies? Please. I'm not going to have 2^64 interfaces anytime soon.
Why, do I need to quote Steve Deering to carry enough weight to criticize IPv6? I pointed out in my original posts the disadvantages of the IPv6 addressing scheme.
Interesting that none of the major issues with IPv6 are addressed by an idiot moderator who doesn't know what to do with his/her moderation points. Guys, when you get moderation points, only moderate the stories you're an expert on. Even the people who go to the "universal adoption of IPv6" Scotch BOFs at the IETF would agree with many of these points. In particular, Steve Deering, the author of SIP, which later merged with a number of other things to become IPv6, would agree that 128 bit IP addresses is overkill, and SIP had only 64 bit addresses originally.
CmdrTaco: if you let moderators do stupid things like this (and yes, there are more stupid moderators than smart ones), you're going to alienate all your clueful posters.
So keep it in your shoes.
This sounds a lot like how the airports are enforcing "security:" respond to exploited threat models, and avoid publicising the known ones.
xenocide2, what's your social security number, mother's maiden name, and which credit cards do you carry? Can you give me their numbers, or do you have something to hide? How about your home address, and phone number? Passwords to computer accounts? A list of all your purchases, including those you made in cash, over the last year? A list of all the web pages you've hit, ever? Your income history, and tax returns, for the last 7 years (you know the IRS wants you to keep those for that long, right?) All school transcripts?
Why don't you post those all to slashdot, as proof that you're an honest man, and that you're following your set of "moral codes."
GPS uses two channels for positioning (L1 @1575.42 MHz and L2 @1227.60 MHz) and one for nuclear test detection (L3 @1381.05 MHz), none of which are anywhere close to 3GHz.
So, why do people who use GPS care? Are they worried about accidental emission in the 1.2-1.6GHz band?
I'm amused by the moderation here. You spend 4 years of your life doing cutting edge research in an area, get published at the top conferences pretty much at will, you understand the protocols and problems in sufficient detail to respond to posts without a reference. You see a story posted referring to a website written by a few morons at a no-name state school who have security tips far below the best current practice, and you point out that such tips are bogus, but they're trying to sell consulting services.
Point that out, get moderated as Troll and Flamebait. I've gotta start metamoderating.
Not that it matters, since I've got karma to burn, but I'd obviously like my posts to get read...
*sigh* Why is it that the one area we _can_ have near-military quality security, people insist on "make my installation marginally harder to crack than my neighbor's"? Can you imagine if the US government said "I agree that the current security of Los Alamos leaves much to be desired. But nothing can keep out a determined hacker."
If you give heavy weapons to your "determined hacker," I agree. But if you're talking about some moron hiding in the bushes with a laptop and a yagi, then I think I can design a system to keep them out, using commercial off-the-shelf (and possibly free) software.
The physical analogy breaks down, since clearly even the government has problems breaking the encryption easily accessable to civilians, while it has no such trouble breaking into civilian buildings (excluding Waco). If we all had access to tanks, antiaircraft missles, and nukes, I probably could keep you a good distance from my home =)
Not really; it's like closing the door. I'd hardly call script kiddies "really determined," but any of them can run airsnort.
But when I hear someone register, then I can get in. Kinda like plaintext password authentication.
While I agree it's a good idea, it's not going to keep the baddies out of the network. For example, the latest firmware for Lucent WaveLAN automatically generates a somewhat random IV, which prevents some of the IV collision attacks documented in the literature. It doesn't stop the fundamental insecurity of WEP, though, and giving people a false sense of security, rather than using a real solution like firewalling the wireless network and only allowing users in through tunneling (such as VPN or SSH tunneling), may be quite harmful.
They are so far off from the best current practices that it's quite pathetic. Anyone who gives a list of security tips like that is unlikely to get my business as an burgler alarm system vendor.
Tell that to the military, or to NASA, or to anyone else with a $100million hunk of metal in the sky.
Put a firewall behind the AP, and use some kind of secure tunnel (such as SSH) to get to a functional part of the network.
I don't think I'll be using their Consulting Services any time soon...
And if I were willing to code up a specialized OS to run my huge (single) program, I wouldn't be in user mode, now would I. This is a tradeoff I've actually considered, since Itaniums are somewhat pricey. Of course, typically your time is more expensive than a shiney new Itanium, even if the latter costs $100k.
Incidentally, I considered whether or not to make the 4GB per process in user space argument, but someone would doubtless raise the large memory extensions to Linux. In any case, since the hardware supports 64GB, you could use 60GB as process-managed swap and know that random access in that area is legal.
As it stands, RAM is so cheap that if you needed 64GB RAM, you could just buy it without having it raise the price of your box too much. It's stupid for Intel to keep cranking out 32-bit processors, and hopefully they'll get Hammered for their trouble and have to bring out Yamhill.
The standard reference, incidentally, is
Phil Karn, "MACA - A New Channel Access Method for Packet Radio". Proceedings of the 9th ARRL Computer Networking Conference, London, Ontario, Canada, 1990.
There are four multihop routing protocols currently under consideration at the IETF MANET WG.
... if you can't run the apps.
Intel x86 is restricted to 48-bit addressing (with segment registers), and practically 64GB with modern OSes. (http://linux-mm.org/)
If I want more than 64GB of addressable physical memory (which I do for some apps), then who cares if you can give me a 32-bit x86 running at 900GHz, it's not going to do diddly squat for me, since _going over the PCI bus_ for swap is going to kill me vs a 1.6GHz 64-bit processor. And since you need to go over the PCI bus just to get to a pseudo-disk stuffed with RAM, that solution is still bogus.
I see your point that this isn't what Joe Blow's gonna put on his desk. But the improved address space is definately a big win, and that's assuming that they can't ramp up the clock speed in a hurry.
Since the source code is the preferred form of making modifications, what's the preferred form of making modifications to your DNA?
6. Have the security personnel haul it away as unattended luggage... get charged with theft of service and reckless endangerment
I could see using a 3870 as a laptop replacement with an 802.11 card. As a PDA with WinCE, its calendar sucks compared to DateBk4, it doesn't have travel management software like TravelTracker, the lack of something like MidCapsHack on the block recognizer makes it somewhat less useful, things run super-slow, and there's no free SSH client. Oh yeah, and the dev environment is a pain in the tush.
The Linux support for the 3870 is coming slowly, but it's not going to replace my datebook. There isn't a decent calendaring program yet for iPaq linux, and that's a necessary prerequisite to being a PDA. Not to mention the total lack of an address book. And don't get me started on power management issues...
Obviously, there's a reason I have an iPaq, but it sure as heck isn't because I think it's a PDA. If I lost my Vx, I'd get a PalmOS box, even though switching over to the iPaq would be free.
Good for you if you've found a way to carry the brick of a PDA that the iPaq is without having it drag your pants off. I'm sticking with my Palm for the apps, speed, battery life, size, and weight.
How about Teledesic? They want to launch a 288-satellite constellation by 2005.
According to their FAQ, Teledesic's primary investors are telecommunications pioneer Craig McCaw, Microsoft Chairman Bill Gates, Motorola, Saudi Prince Alwaleed Bin Talal, Abu Dhabi Investment Company and Boeing. Sounds like there's enough money there to sink an aircraft carrier...
No antiskip? What's that 10sec/40sec ESP switch on the back? I drove from Nashville to Houston with one of these guys and it never skipped a single time, even in the 10sec mode. I also used it on about 9 continuous days (216 hours) of flying time (~100k mi) and I've never had it skip, not even in the worst of turbulence. (Obviously, it wasn't ever on for landing, but we lost an engine once and experienced some pretty bad vibration from that).
I wouldn't train for a marathon with an MP3 CD player, because it definately does have moving parts, but the solid state stuff would be just fine.
I've had a 3870 for about a week. I use a Vx as my regular PDA. The 3870 is kinda neat, with its color screen, but it's too bulky to carry everywhere.
I could see using a 3870 as a laptop replacement with an 802.11 card. As a PDA with WinCE, its calendar sucks compared to DateBk4, it doesn't have travel management software like TravelTracker, the lack of something like MidCapsHack on the block recognizer makes it somewhat less useful, things run super-slow, and there's no free SSH client. Oh yeah, and the dev environment is a pain in the tush.
The Linux support for the 3870 is coming slowly, but it's not going to replace my datebook. There isn't a decent calendaring program yet for iPaq linux, and that's a necessary prerequisite to being a PDA. Not to mention the total lack of an address book. And don't get me started on power management issues...
Synce doesn't work yet, either.
Obviously, there's a reason I have an iPaq, but it sure as heck isn't because I think it's a PDA. If I lost my Vx, I'd get a PalmOS box, even though switching over to the iPaq would be free.
They'd need ISPs who run DNS servers for their clients to point to their root servers. This is somewhat nontrivial.