Locking down open computing

DTrace was made available for the new version of Mac OS X

How open should computers be, asks regular columnist Bill Thompson.

These tools would look at my thousands of lines of code and check that I had all my brackets and semi-colons in the right place and that I hadn't mis-spelled the names of variables or functions.

I also relied on more serious debugging software, programs like 'dbx' that could investigate the inner workings of other programs, monitoring them as they ran and giving me complete access to the instructions I was executing and the data structures they were manipulating.

Tracing running programs in this way is hard and detailed work, but it is often the only way to spot subtle errors, and a lot of work has gone into improving such tools in the years since I was working on sixteen-user UNIX systems with a generous 512Mb of RAM.

One of the best tracing programs around is DTrace, developed by Sun Microsystems for use on its Solaris operating system.

DTrace is available under an open source license, and when Apple announced that it would be available on Leopard, the new version of Mac OS X, every serious Mac OS programmer looked forward to having a new, powerful tool to work with.

Unfortunately early experiments with the Apple version of DTrace identified some unusual behaviour.

Cable ties

Adam Leventhal, one of its original developers, found that he could not see any information about iTunes, apparently because Apple had modified his tool to ignore some of its own programs.

Leventhal is rather annoyed about this, because the point of a trace program is that it can see everything in order to help developers find and fix errors.

Digital rights management is not, in itself, an objectionable technology

Apple has not made any comment on his findings, but the general consensus is that iTunes is being shielded to protect details about how it implements FairPlay, the digital rights management system that Apple uses to limit the uses of music and video files downloaded from their online store.

And Apple is probably doing this because it has been told to by the content industries, the companies that package and sell the products of other people's creativity.

This would not be too surprising, and Apple is certainly no worse than other companies in limiting what users and developers can see and do.

Microsoft makes it almost impossible to get inside its Xbox 360 games console, resulting in the absurdity of having to get a special cable if you want to transfer your information to a new console when you upgrade. It also doesn't open the console up to developers.

Modifying DTrace is also perfectly legitimate, if irritating.

'protected content'

Apple is perfectly entitled to change software in any way it wants within the law, even if it does reveal yet again just how much power the record companies have over the computing industry.

Vista also contains technology aimed at protecting content

The inner workings of a complex debugging tool may seem like the sort of issue that only affects programmers, but it has a direct impact on every Mac user since it makes it harder to find and fix problems in software, especially software written by independent developers.

Like many Mac users, I rely on a range of free and open source tools like the Acorn image editor or the twhirl twitter client, so I have a direct interest in ensuring that the programmers behind them have proper access to the internals of the operating system.

And it also shows the sort of issues that can arise when any part of a complex computing environment is restricted in order to satisfy requirements that have nothing to do with effective operation and are solely motivated by a desire to limit what users can do.

It's the same with Microsoft Vista, where vast efforts have been made to ensure that "protected content" like high-definition video doesn't leak out of the controlled environment.

This has an effect on system performance and on hardware compatibility that can seriously affect the user experience.

Picture record

The restrictions are not really a serious problem.

Landon Fuller has already posted details of a workaround, although there is no sign yet of Apple responding to Leventhal's point that "Apple has done a service by porting DTrace, but let's convince them to go one step further and port it properly".

The Mukurtu project uses DRM effectively

And digital rights management is not, in itself, an objectionable technology.

Encrypting e-mail so that they can only be read by the intended recipient is a way of managing the readership of a document, and a vital one for anyone wanting to use the public internet for private communications.

It is also useful in helping groups of people keep control and ownership of material that is important to them for non-commercial reasons.

For example an Australian Warumungu community has created a digital archive that uses DRM to enforce rules that they consider vitally important when dealing with photographs, because only elders can look at sacred objects, while images of dead people should not be viewed and other objects may be restricted by family or gender.

The Mukurtu Wumpurrarni-kari archive uses DRM to help the community manage these rules, although it also allows individuals to decide to vary or even break them, recognising that the technology should be at the service of its users and not the other way around.

It is a lesson that the record industry seems slowly to be learning, as more and more online services offer unlocked MP3s to download.

Perhaps Apple will eventually free DTrace from its restrictions, just as Steve Jobs has worked to get rid of DRM on music.

Source from: news.bbc.co.uk

Read More..

Net firms reject monitoring role

All net firms keep an eye on how much people download

UK net firms are resisting government suggestions that they should do more to monitor what customers do online.

The industry association for net providers said legal and technical barriers prohibit them from being anything other than a "mere conduit".

The declaration comes as the government floats the idea of persistent pirates being denied net access.

And in the US one net supplier has admitted to "degrading" traffic from some file-sharing networks.

Traffic control

Net firms have been stung into defining their position by the emergence this week of a draft government consultation document that suggests ISPs should be drafted in to the fight against piracy.

It suggested that people who persistently download and share copyrighted material could have their net access removed.

A spokesman for the Internet Service Providers Association (ISPA) said the 2002 E-Commerce Regulations defined net firms as "mere conduits" and not responsible for the contents of the traffic flowing across their networks.

If they didn't do traffic management we would all complain

The spokesman said technical issues also made it hard for net firms to take action against specific types of traffic.

For instance, he said, while some people use peer-to-peer networks to download copyrighted material many commercial services, such as Napster and the BBC's iPlayer, use file-sharing technology to distribute music and TV legally.

In the US, Comcast admitted in documents filed with the Federal Communications Commission that it does "degrade" some traffic from peer-to-peer networks.

The spokesman added: "We know that all ISPs are involved in traffic management but that is to optimise the service for all their customers."

A spokesman for Virgin Media said its traffic management system came into play during peak times - between 1600 and 2100.

Action was taken against any customer whose usage exceeded a limit associated with their tariff during that five hour window, he said.

"If you exceed that threshold we will drop your speed for five hours from when the excess is recorded," he said.

Browsing speeds are most often managed during the busiest times

Andrew Ferguson, an editor at Think Broadband, said net service firms manage their bandwidth in many different ways.

Almost all, he said, manage traffic but at certain times impose other systems to smooth out the peaks.

"Some firms will happily let you use as much as you like but will charge you accordingly, and business products that are more expensive often allow unlimited use," he said.

Others impose charges on customers who regularly exceed their download limits and a few manage their system so users cannot exceed a monthly download cap. The limits that firms impose can also vary widely.

"Any ISP that does not do traffic management is not going to stay in business very long," said Gavin Johns, managing director of net management firm Epitiro.

He said it was essential to ensure that services which have to be delivered in real time, such as voice and streaming video, were usable.

"Different applications use different ports and have different payloads," said Mr Johns, "They look completely different from a network point of view."

"If they didn't do traffic management we would all complain," he said.

Mr Ferguson from Think Broadband said although traffic management was common, net providers imposed it in contrasting ways.

"What varies is the degree it impacts users and the openness of providers in telling users it exists and what is and is not managed," he told the BBC News website.

"Traffic management has a poor reputation as in many cases it is used to keep bandwidth costs down for a provider with little respect to the consumers' wishes," he said.Building a nation Voters, boycotters Media spotlight

Source from: news.bbc.co.uk

Read More..

Locking down open computing

DTrace was made available for the new version of Mac OS X

How open should computers be, asks regular columnist Bill Thompson.

These tools would look at my thousands of lines of code and check that I had all my brackets and semi-colons in the right place and that I hadn't mis-spelled the names of variables or functions.

I also relied on more serious debugging software, programs like 'dbx' that could investigate the inner workings of other programs, monitoring them as they ran and giving me complete access to the instructions I was executing and the data structures they were manipulating.

Tracing running programs in this way is hard and detailed work, but it is often the only way to spot subtle errors, and a lot of work has gone into improving such tools in the years since I was working on sixteen-user UNIX systems with a generous 512Mb of RAM.

One of the best tracing programs around is DTrace, developed by Sun Microsystems for use on its Solaris operating system.

DTrace is available under an open source license, and when Apple announced that it would be available on Leopard, the new version of Mac OS X, every serious Mac OS programmer looked forward to having a new, powerful tool to work with.

Unfortunately early experiments with the Apple version of DTrace identified some unusual behaviour.

Cable ties

Adam Leventhal, one of its original developers, found that he could not see any information about iTunes, apparently because Apple had modified his tool to ignore some of its own programs.

Leventhal is rather annoyed about this, because the point of a trace program is that it can see everything in order to help developers find and fix errors.

Digital rights management is not, in itself, an objectionable technology

Apple has not made any comment on his findings, but the general consensus is that iTunes is being shielded to protect details about how it implements FairPlay, the digital rights management system that Apple uses to limit the uses of music and video files downloaded from their online store.

And Apple is probably doing this because it has been told to by the content industries, the companies that package and sell the products of other people's creativity.

This would not be too surprising, and Apple is certainly no worse than other companies in limiting what users and developers can see and do.

Microsoft makes it almost impossible to get inside its Xbox 360 games console, resulting in the absurdity of having to get a special cable if you want to transfer your information to a new console when you upgrade. It also doesn't open the console up to developers.

Modifying DTrace is also perfectly legitimate, if irritating.

'protected content'

Apple is perfectly entitled to change software in any way it wants within the law, even if it does reveal yet again just how much power the record companies have over the computing industry.

Vista also contains technology aimed at protecting content

The inner workings of a complex debugging tool may seem like the sort of issue that only affects programmers, but it has a direct impact on every Mac user since it makes it harder to find and fix problems in software, especially software written by independent developers.

Like many Mac users, I rely on a range of free and open source tools like the Acorn image editor or the twhirl twitter client, so I have a direct interest in ensuring that the programmers behind them have proper access to the internals of the operating system.

And it also shows the sort of issues that can arise when any part of a complex computing environment is restricted in order to satisfy requirements that have nothing to do with effective operation and are solely motivated by a desire to limit what users can do.

It's the same with Microsoft Vista, where vast efforts have been made to ensure that "protected content" like high-definition video doesn't leak out of the controlled environment.

This has an effect on system performance and on hardware compatibility that can seriously affect the user experience.

Picture record

The restrictions are not really a serious problem.

Landon Fuller has already posted details of a workaround, although there is no sign yet of Apple responding to Leventhal's point that "Apple has done a service by porting DTrace, but let's convince them to go one step further and port it properly".

The Mukurtu project uses DRM effectively

And digital rights management is not, in itself, an objectionable technology.

Encrypting e-mail so that they can only be read by the intended recipient is a way of managing the readership of a document, and a vital one for anyone wanting to use the public internet for private communications.

It is also useful in helping groups of people keep control and ownership of material that is important to them for non-commercial reasons.

For example an Australian Warumungu community has created a digital archive that uses DRM to enforce rules that they consider vitally important when dealing with photographs, because only elders can look at sacred objects, while images of dead people should not be viewed and other objects may be restricted by family or gender.

The Mukurtu Wumpurrarni-kari archive uses DRM to help the community manage these rules, although it also allows individuals to decide to vary or even break them, recognising that the technology should be at the service of its users and not the other way around.

It is a lesson that the record industry seems slowly to be learning, as more and more online services offer unlocked MP3s to download.

Perhaps Apple will eventually free DTrace from its restrictions, just as Steve Jobs has worked to get rid of DRM on music.

Source from: news.bbc.co.uk

Read More..