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The story is old: In Andrew Tanenbaum's 'Computer Networks' (1981) book, the Chapter 1, Problem 1, states:
Imagine that you have trained your St. Bernhard, Bernie, to carry a box of three floppy disks instead of a flask of brandy. (When your disk fills up, you consider that an emergency.) These floppy disks each contain 250,000 bytes. The dog can travel to your side, wherever you may be, at 18 km/hour. For what distances does Bernie have a higher data rate than a 300 bps phone line?
Since 1981, there has been dozens, probably hundreds, derivatives of this 'problem'. Tanenbaum's book was so popular that we can assume that those creating derivatives in the 1980s and 90s were all familiar with Tanenbaum's problem statement. Those coming later either know of Tanenbaum, or they have learned of other Tanenbaum derivatives.
When I was teaching computer networking in the early 1990s, I used this problem in one final exam - but I had to update it to a box of 10 CDs, each 640 MByte, to be compared to a 2B ISDN line (128 kbps). I also asked the students to consider other aspect of this kind of communication. One pointed out the retransmission time in case of a checksum error. Another one referred to line noise in the form of bitches in heat along the route. A third one remarked that the data was physically protected from theft.
Note that Tanenbaum's problem statements point to one essential aspect: The distance. Most derivatives point only to the bit rate. You can have a tremendous bit rate on short distances, but once you need to access a server a few hundred or thousand kilometers away, then both Bernie and pigeons loose the game.
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Mike Hankey wrote: transfer packets by donkey!
Wouldn't that be by burro?
In my part of the world VDSL2 at 100 Mbps is standard, with 1 Gbps fiber network available in many places.
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.
-- 6079 Smith W.
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In India, moderately high-speed fiber is readily available for anyone living in a township. That too at a very affordable rate. I pay around Rs. 900/- for 100Mbps fiber connection with unlimited data and additional perks like access to some OTT platforms. Felt kind of counterintuitive that it is better in India.
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I guess part of the explanation is that earlier, there were close to nothing in major parts of India.
A couple of parallels: Norway was the first country to replace an analog phone system with a 100% digital one. We were not the first country to have a 100% digital phone system - there were developing countries that never had any analog phone network. When they got one, in the early 1990s, it was digital all the way from day 1, before we threw out our last analog phone switch.
A second example: In the 1970s, Norwegians saw Sweden as the rich uncle. Stereo freaks read about those grand stereo systems almost every Swedish family could afford. We couldn't. When the oil made us rich, and we could afford something similar, CDs and digital technology had arrived. Vinyl was old style. The Swedes had invested millions in analog and vinyl, and were not ready to throw it out for digital technology for quite a few years. Old Norwegian stereo freaks (there were a few!) were used to go to Sweden to find a much greater selection of vinyls than available in Norway. With CDs, it was no use going to Sweden; they recognized CDs 5-10 years after we did. For years, Swedes wanting CDs came to Norway to find a good selection.
A third example: One major reason why Norway was the first country to go all digital for radio broadcasting: We were late building an FM network; it was established from the mid-1960s to the mid-70. Other countries, such as Sweden, was 10 years ahead of us. So their first generation of transmitters were getting outdated and replaced in the 1990s, for their second generation. The newer Norwegian network could last for another 10-15 years.
Then comes DAB, at a time when our first generation FM transmitters were getting really old, and had to be replaced one way or another. With DAB ready for use, investing tens of millions in a second generation analog FM network in the early 2000s makes little sense, so we went for a digital solution, which has been a great success. The Swedes say: We are not going to throw out our old FM transmitters that are good for another 10-15 years! To make it clear, they claimed that they never want to go for DAB. Well, let's see when their FM transmitters fall apart in a few years. Maybe they in 2030 will spend a hundred millions on updating their analog technology. Maybe they won't.
Many other countries are in a similar situation, having not-so-old FM transmitters. But as these need replacement, they are not stubbornly rejecting digital, like the Swedes: DAB is slowly coming in wherever a full modernization is required.
Back to India: You also got a nationwide digital radio system quite early, although not DAB, but DRM. If we had been open to DRM (or preferably DRM+) here, it would have been much better suited for small, local community radios, and the agitation against DAB would have been much less. DAB requires a large infrastructure, poorly suited for community radio. DRM+ transmitters are great for single- (or few-)transmitter, single- (or few-)channel radios, well suited for what Americans often refer to as 'husband-and-wife radio stations'. It is a pity that we didn't go for that, for the community radios.
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I'm with Virgin who are fibre from server to house 200mb download 25mb upload
In a closed society where everybody's guilty, the only crime is getting caught. In a world of thieves, the only final sin is stupidity. - Hunter S Thompson - RIP
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Does the doctor recommend 1GB or 2GB?
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definitely 2GB, but I need to upgrade my home to Cat 6 before I can take advantage.
I figured out my WiFi will handle gigabit speeds at least, but double the ping times.
To err is human. Fortune favors the monsters.
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So the cat needs more fiber, too?
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I have 5 / 50 (gould get up to 88 but there is no offer for 100 from my provider) through directional radio. Otherwise we'd only have DSL cabled, with a pitiful 0.5 / 20 on good days.
GCS/GE d--(d) s-/+ a C+++ U+++ P-- L+@ E-- W+++ N+ o+ K- w+++ O? M-- V? PS+ PE Y+ PGP t+ 5? X R+++ tv-- b+(+++) DI+++ D++ G e++ h--- r+++ y+++* Weapons extension: ma- k++ F+2 X
The shortest horror story: On Error Resume Next
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Curious question to those responding in this thread, referring to speeds in so and so many MB or GB:
I have met countless people - the majority of them programmers - who never considered the meaning of mega/giga in networking, never realized that a network mega or giga is almost a magnitude (but due to protocol overhead usually slightly more than a magnitude) less than a mega or giga of RAM. There is no law requiring B to mean Byte and b to mean bit, but it is a strong convention. Networking people know very well that network speeds are always stated in bits per second. Generally, they prefer the term bps (Kbps, Mbps, Gbps); I have never seen MB or GB used in networking literature. (Furthermore; networking people never abuse kilo, mega and giga: 1 Mbps is 1,000,000 bps rather than 1 Gi bps, or 1,073,741,824 bps - but that is a different question.)
When we 30 years ago got ISDN speeds, there were customer making formal complaints to the telco: They got a throughput of only 8 kilobytes per second, but had been promised 64! Line speeds in those days were at a level where you actually experienced it as a limitation. Today's fiber speeds are at a level where 99% of the users won't notice whether they get 100 Mbit/s or 100 Mbytes/s. Any noticeable delay, or speed limitation, is because the server machine is slow in its response.
The only thing I know for sure: Those referring to speeds of so and so many millibits per second (such as '200 mb') are not serious about it. I am still curious to whether those really mean 200 Mibi-Bytes or 200 Mega-bits!
So how many of you think Mega- (or Mebi-)bytes when writing 'MB'? How many think of Mega-bits?
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TBH, I realize network comms are measured in bits, not bytes. I subconsciously divide by 8 when estimating my download speeds.
The problem I have is remembering the proper casing for all the abbreviations.
Ergo, I'm giving you the correct figures, but maybe the wrong units. Sorry.
To err is human. Fortune favors the monsters.
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Did he retire? Hopefully nothing worse than that.
I’ve given up trying to be calm. However, I am open to feeling slightly less agitated.
I’m begging you for the benefit of everyone, don’t be STUPID.
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Vacation. For the next two weeks, I'm the news captain now.
Thanks,
Sean Ewington
CodeProject
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Ok, glad he is taking a break.
I’ve given up trying to be calm. However, I am open to feeling slightly less agitated.
I’m begging you for the benefit of everyone, don’t be STUPID.
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Will you include a load of Pirate news?
"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
"Common sense is so rare these days, it should be classified as a super power" - Random T-shirt
AntiTwitter: @DalekDave is now a follower!
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Y'arrrr. No.
Thanks,
Sean Ewington
CodeProject
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Everyone has right to have some days off... even he
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
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I would expect a loooong therapy session.
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In June we are headed to Scotland and Ireland for 2 weeks from Atlanta, Georgia USA. I know we'll need adapters for anything that needs to plug into an outlet. This question is about using USB-A or USB-C charging cords. If I plug into a USB outlet in those countries with my USB cord will I have problems?
Airports and hotels in the US have outlets with the normal electrical outlet plus a couple of USB-A jacks. Do hotels in Scotland and Ireland have similar setups? If not then I'm bringing an adapter and a power strip.
Thanks for the help.
I’ve given up trying to be calm. However, I am open to feeling slightly less agitated.
I’m begging you for the benefit of everyone, don’t be STUPID.
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I can't tell about the USB C because I still have to own something that has it.
My phone chargers are USB A on the side of the adapter pluged in the wall and micro usb in the side of the phone.
I don't think the cable will do any problem, USB voltage should be the same (as a standard), the difference is in the voltage net, and that is the job of the adapter charger.
About Scotland and ireland having such adapters... I can't tell. You will need to wait for anopther CPian that knows it for sure.
I would recommend you to anyways bring your adapter if you already have it. It will make your like easier.
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
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The USB cables should be fine if the hotel provides sockets (and most hotels do). But it's always an idea to bring (or buy) a plug adapter. And don't forget that over here our mains power is pumped out at 240 volts, so will give some of your equipment a bit of a kick.
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And there is a certain risk connecting a device to an unknown usb end.
As you suggested, an adapter is much more safe or then an USB cable which only is for charging and no datatransfer
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USB cables are generally used for both purposes, and wall adapters will be stepped down to about 5.5. volts.
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