The usual problem is that when you use only one method of backup, the case of restoring a single file deleted by a user requires the tape that is offsite and needs to be fetched first. So you should use different methods and/or different schedules for quick file restoration and for disaster recovery.
That is why we backup to disks in another server over the network (daily) and backup to tapes sent to another location (weekly). The usual "user deleted or damaged a file" case is quickly handled using the disks. No need to walk to the computerroom to insert a tape, and wait for it to load and seek. The offsite weekly backup is for disaster recovery.
CID information was never designed nor intended to be in any way secure.
PBXs have always had the ability to set outgoing CID information - so, for example, all outgoing calls would appear on the receiver's CID box as coming from a company's main switchboard rather than whatever extension they were actually originating from.
When a PBX is connected to a line with multiple numbers (number block or MSN) it is only valud to present an outgoing number in this block. So yes, you can send a main switchboard number, but you cannot send someone else's number.
The system was reasonably secure as long as reputable telephone companies managed the public exchanges and made sure every line was correctly configured w.r.t. incoming and outgoing CID info. But now, just about anyone can start a phone company and offer the routing of phone traffic without the sensible management of security etc. VoIP carriers are just one example of that, other mishaps have occurred with alternative carriers etc.
>First of all, get off of the SATA hacks, and realize you're going to need to go to SCSI
You must have missed the fact that per-unit capacity for SATA drives is significantly higher than for SCSI drives. And then I'm not even talking about per-megabyte cost of SCSI storage when compared to SATA storage...
It seems like you are using a hammer, and now see every problem as a nail.
Actually, 433 MHz is in a band allocated to amateur radio (HAM radio) and radiolocation (radar and positioning equipment). Unlicensed lowpower devices are allowed to use a small part of this band, but they have to accept interference from the other services.
Many radio amateurs are allowed to output about 100 Watts at this frequency, which of course completely swamps the milliwatt signal of the car keys. The radio location service can output megawatts of pulse power.
The frequency is also used by many other lowpower wireless devices. Interferences is very often a problem. Don't buy products using this technology.
In fact, they know that they have built in vulnerabilities in their OS, their browser and their other applications from the time they implented all kinds of "active scripting" in them, and they do not seem to be bothered. All the blame is passed onto the user every time, and the whole discussion whether adding these features ever was a good idea is never taken on. They don't mind, as the features are considered cute and sell programs, and security has never sold anything.
The problem is that patents are so expensive that only megacorporations like Microsoft, with too much money on them from overcharging the customers and underspending on development and testing, can afford to use the hailshot patent approach.
Sure you can setup a fund and obtain 10 patents, but Microsoft will just laugh at you. You need to get thousands of patents to slightly affect them.
The patent system whas devised to provide a protection mechanism for the one single invention or idea that was behind the product you were manufacturing, to prevent competitors from just walking away with the worked-out idea and start production without research and development.
Now it is being abused as a way to wipe out any competition by patenting each and every detail of products, so that any competing development will always be hindered by this. There is only one hope: that this mechanism will implode all by itself, because at some time the legal system is no longer able to handle all cases of corporations fighting over their patents.
>As to the rest of it - you don't understand info theory.
Why do you write that? In my posting I clearly indicate that for a high bitrate in a low bandwith you need a good SNR, which you don't have. You post a few calculations with that, and use that to prove I don't understand info theory. But you are claiming exactly the same thing.
Remember that you cannot choose the frequency at will. If you want to transfer a few megabits per second, you are going to end up with bandwith of the order of a few Megahertz. Clever systems that get the most bitrate out of the bandwidth depend on a good signal/noise ratio, something you don't have on a powerline. Combined with the given length of the powerline, you will have to live with the fact that it is to function as a transmission line.
The problem is that the powerlines are a bad transmission line for high frequencies, because they are designed for use at 50 or 60 Hz only. So the use of RF on these lines is limited to a couple of MHz, you cannot carry things like WiFi (2400 MHz) over powerlines.
Of course the use of low frequencies also limits the bitrate. As it is also shared between subscribers on the same power segment, the bitrate per subscriber is not very attractive.
Use of power lines for broadband should be abandoned. More suitable lines should be used. Even telephone lines are more suitable (also because there are separate lines to each subscriber). Or else, more suitable lines (like fiber) should be put in place.
It is a commercial playing field. The players have to pay for the equipment. Don't worry. A complete plane and its maintenance costs way more than a radio.
Technology progresses, and just as we don't keep using our old PC XT, 14k4 modem and floppy disk drive they should not use outdated technology that has disadvantages that modern technology has solved.
Their dogma seems to be "we have always done it this way and it would be sooooooo difficult to try to get everybody to do it another way that we prefer to keep things the same forever".
It's everything the people who designed the internet fought against
There has been very little fighting against spam from the people who designed and fathered the Internet. Sad, but true. When the mighty corporations take over and do things they don't like, it is mainly their own fault. Internet mail, important as it is today, probably cannot and should not be handled by a "simple" protocol (the S in SMTP means "simple") that is so easily subverted and abused.
The Internet community should have come up with a solution instead of fighting about how this would break some special setup or some "right" that certain people seem to infer from the fact that the Internet was not regulated at a time in the past.
Lately, at work we have been plagued at work by a deluge of virus mail and bounce-mail, plus a heap of german racist spam, and bounces of that. Probably most of the world has this problem.
I have tried to complain about virus-infected systems at ISP abuse desks, but apart from 2 or 3 exceptions most ISPs either to nothing after sending a standard "we are processing your complaint but cannot guarantee a personal reply" auto-reply message, or worse we get something like this:
However, we would like to point out that neither [ISP] nor her partners are responsible for the behaviour by subscribers to the [ISP] Internet Service on the internet.
Now I wonder, is that really true? Is an ISP "not responsible for the behaviour of its subscribers" when, at the same time, this ISP is not timely handling abuse reports, and is not disclosing contact information of their clients indexed by IP address?? They can declare themselves "not responsible" but I wonder what the legal situation is.
I would think that they can avoid their responsibility only when they allow the victims of their customer's activities to take action themselves. That would mean they need to provide whois-like information about the fixed IP addresses of their customers. As it is now, a cable or ADSL account is a semi-anonymous hiding place for virus-infected Windows systems that send SPAM and viruses all day long, and nobody except law enforcements agencies is able to contact the unknowingly guilty party. The latter are of course not interested in taking up individual cases.
ISPs should either be held "responsible for their customer's activities", or publish enough information to allow others to take action against them.
That works well because many of the current viruses open with "EHLO yourdomain". When you reject those connections you block all those virus delivery attempts. Blocking the IP address probably blocks a lot of SPAM.
We also block all mail claiming to be "from anyone@ourdomain" at the outside mailserver (both in the envelope and the From: header). This should block forgeries and also blocks one of the viruses.
I know that it "could block legitimate mail". I don't care. We don't authorize the use of an inside mail address from an outside mail service.
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The usual problem is that when you use only one method of backup, the case of restoring a single file deleted by a user requires the tape that is offsite and needs to be fetched first.
So you should use different methods and/or different schedules for quick file restoration and for disaster recovery.
DVD provides no useful storage capacity.
A single 300GB ATA drive stores over 60 DVDs.
That is why we backup to disks in another server over the network (daily) and backup to tapes sent to another location (weekly).
The usual "user deleted or damaged a file" case is quickly handled using the disks. No need to walk to the computerroom to insert a tape, and wait for it to load and seek.
The offsite weekly backup is for disaster recovery.
CID information was never designed nor intended to be in any way secure.
PBXs have always had the ability to set outgoing CID information - so, for example, all outgoing calls would appear on the receiver's CID box as coming from a company's main switchboard rather than whatever extension they were actually originating from.
When a PBX is connected to a line with multiple numbers (number block or MSN) it is only valud to present an outgoing number in this block. So yes, you can send a main switchboard number, but you cannot send someone else's number.
The system was reasonably secure as long as reputable telephone companies managed the public exchanges and made sure every line was correctly configured w.r.t. incoming and outgoing CID info.
But now, just about anyone can start a phone company and offer the routing of phone traffic without the sensible management of security etc. VoIP carriers are just one example of that, other mishaps have occurred with alternative carriers etc.
>HDD units are typically around 20-30 watts
SCSI drives, maybe. Or older types of drives.
A typical modern 300GB ATA drive runs at 10 watts in-use (and less when idle).
>First of all, get off of the SATA hacks, and realize you're going to need to go to SCSI
You must have missed the fact that per-unit capacity for SATA drives is significantly higher than for SCSI drives.
And then I'm not even talking about per-megabyte cost of SCSI storage when compared to SATA storage...
It seems like you are using a hammer, and now see every problem as a nail.
Actually, 433 MHz is in a band allocated to amateur radio (HAM radio) and radiolocation (radar and positioning equipment).
Unlicensed lowpower devices are allowed to use a small part of this band, but they have to accept interference from the other services.
Many radio amateurs are allowed to output about 100 Watts at this frequency, which of course completely swamps the milliwatt signal of the car keys.
The radio location service can output megawatts of pulse power.
The frequency is also used by many other lowpower wireless devices. Interferences is very often a problem. Don't buy products using this technology.
In fact, they know that they have built in vulnerabilities in their OS, their browser and their other applications from the time they implented all kinds of "active scripting" in them, and they do not seem to be bothered.
All the blame is passed onto the user every time, and the whole discussion whether adding these features ever was a good idea is never taken on.
They don't mind, as the features are considered cute and sell programs, and security has never sold anything.
The problem is that patents are so expensive that only megacorporations like Microsoft, with too much money on them from overcharging the customers and underspending on development and testing, can afford to use the hailshot patent approach.
Sure you can setup a fund and obtain 10 patents, but Microsoft will just laugh at you. You need to get thousands of patents to slightly affect them.
The patent system whas devised to provide a protection mechanism for the one single invention or idea that was behind the product you were manufacturing, to prevent competitors from just walking away with the worked-out idea and start production without research and development.
Now it is being abused as a way to wipe out any competition by patenting each and every detail of products, so that any competing development will always be hindered by this.
There is only one hope: that this mechanism will implode all by itself, because at some time the legal system is no longer able to handle all cases of corporations fighting over their patents.
With patent b you can still make phonecalls, just not send them over IP. What is the difference?
>You claim that bitrate is dependent solely on bandwidth, when its dependent on bandwidth and SNR jointly.
My claim is that you cannot, or don't want to, read. And I'll leave it at that.
>As to the rest of it - you don't understand info theory.
Why do you write that?
In my posting I clearly indicate that for a high bitrate in a low bandwith you need a good SNR, which you don't have.
You post a few calculations with that, and use that to prove I don't understand info theory.
But you are claiming exactly the same thing.
Remember that you cannot choose the frequency at will. If you want to transfer a few megabits per second, you are going to end up with bandwith of the order of a few Megahertz.
Clever systems that get the most bitrate out of the bandwidth depend on a good signal/noise ratio, something you don't have on a powerline.
Combined with the given length of the powerline, you will have to live with the fact that it is to function as a transmission line.
The problem is that the powerlines are a bad transmission line for high frequencies, because they are designed for use at 50 or 60 Hz only.
So the use of RF on these lines is limited to a couple of MHz, you cannot carry things like WiFi (2400 MHz) over powerlines.
Of course the use of low frequencies also limits the bitrate. As it is also shared between subscribers on the same power segment, the bitrate per subscriber is not very attractive.
Use of power lines for broadband should be abandoned. More suitable lines should be used. Even telephone lines are more suitable (also because there are separate lines to each subscriber).
Or else, more suitable lines (like fiber) should be put in place.
Even neater after you read that it was created on November 18, 1997!
And without Microsoft, there would not be so many people who believe that '/' is the backslash character, and that '\' and '/' are somehow equivalent.
No, there actually are ISPs that do this.
I think most of them simply don't care.
Statements like "we are not responsible for the behaviour of our customers" are all too common.
Remember that an account can be considered "abusive" without having sent even a single message.
E.g. Maryam Abacha sends out a spam run via some other way, and tells the recepients to contact her at maryamabacha@hotmail.com
When complaints arrive at Hotmail about this, they should close this account.
It is a commercial playing field. The players have to pay for the equipment.
Don't worry. A complete plane and its maintenance costs way more than a radio.
Technology progresses, and just as we don't keep using our old PC XT, 14k4 modem and floppy disk drive they should not use outdated technology that has disadvantages that modern technology has solved.
Their dogma seems to be "we have always done it this way and it would be sooooooo difficult to try to get everybody to do it another way that we prefer to keep things the same forever".
Aircraft still use VHF AM radio and analog ILS.
Who claimed aviation is at the forefront of new developments?
It's everything the people who designed the internet fought against
There has been very little fighting against spam from the people who designed and fathered the Internet. Sad, but true.
When the mighty corporations take over and do things they don't like, it is mainly their own fault.
Internet mail, important as it is today, probably cannot and should not be handled by a "simple" protocol (the S in SMTP means "simple") that is so easily subverted and abused.
The Internet community should have come up with a solution instead of fighting about how this would break some special setup or some "right" that certain people seem to infer from the fact that the Internet was not regulated at a time in the past.
Lately, at work we have been plagued at work by a deluge of virus mail and bounce-mail, plus a heap of german racist spam, and bounces of that.
Probably most of the world has this problem.
I have tried to complain about virus-infected systems at ISP abuse desks, but apart from 2 or 3 exceptions most ISPs either to nothing after sending a standard "we are processing your complaint but cannot guarantee a personal reply" auto-reply message, or worse we get something like this:
However, we would like to point out that neither [ISP] nor her partners are responsible for the behaviour by subscribers to the [ISP] Internet Service on the internet.
Now I wonder, is that really true? Is an ISP "not responsible for the behaviour of its subscribers" when, at the same time, this ISP is not timely handling abuse reports, and is not disclosing contact information of their clients indexed by IP address??
They can declare themselves "not responsible" but I wonder what the legal situation is.
I would think that they can avoid their responsibility only when they allow the victims of their customer's activities to take action themselves. That would mean they need to provide whois-like information about the fixed IP addresses of their customers.
As it is now, a cable or ADSL account is a semi-anonymous hiding place for virus-infected Windows systems that send SPAM and viruses all day long, and nobody except law enforcements agencies is able to contact the unknowingly guilty party.
The latter are of course not interested in taking up individual cases.
ISPs should either be held "responsible for their customer's activities", or publish enough information to allow others to take action against them.
That works well because many of the current viruses open with "EHLO yourdomain". When you reject those connections you block all those virus delivery attempts.
Blocking the IP address probably blocks a lot of SPAM.
We also block all mail claiming to be "from anyone@ourdomain" at the outside mailserver (both in the envelope and the From: header). This should block forgeries and also blocks one of the viruses.
I know that it "could block legitimate mail". I don't care. We don't authorize the use of an inside mail address from an outside mail service.
It is safe to ignore the potential energy, because it is so much smaller than the kinetic energy.