Doc Searls (Linux Journal guy) has offered up another explanation of the Linux kernel. This explanation is a extension of the “Linux is the trees” analogy which has been discussed in past Linux Journal issues.
I found the link to this article on Kernel Planet.
Inside Risks is the last page column in Communications of the ACM. The Inside Risks column in the September 2005 issue, written by Barbara Simons and Jim Horning, discusses how hard it is to get non-technical people to understand why writing bug-free, and more importantly secure software is so hard. The article offers a nice analogy with the following caveat, “Analogy is a poor tool for reasoning, but a good analogy can be very effective in developing intuition.”
One possibly useful analogy is the U.S. Tax Code. Americans have some sense of its complexity and of the large number of people employed in its interpretation. Tax loopholes are analogous to hidden malicious code or Trojan horses in software.
The tax code resembles software in other ways as well:
- It is intended to be precise and to interface with messy realities of the real world.
- It has been developed in multiple iterations, responding to changing circumstances and requirements.
- The people who wrote the original version are no longer around.
- No one understands it in its entirety.
- It can be difficult to infer intent simply be reading a section.
- There are people who actively seek to subvert it.
Of course, there are also major differences between the tax code and software. The tax code is relatively “small” – although it runs to several thousand printed pages, Windows XP has 40 million lines of source code.
The September 2005 issue of Linux Journal has another nice SSH article. This one is called Managing SSH for Scripts and cron Jobs.
Note worthy is the discussion of how to securely use passphraseless keys for remote command execution.
Also, I didn’t realize that SSH could be used as a pipe target.
cat file | ssh HOST "cat >> file.out"
So EBay thinks that voice calls will be free in the future because calls will be subsidized by advertising. This was their justification for paying way too much for Skype. How they came to this conclusion is beyond me. If anything current trends seem to me to indicate that consumers will use whatever technology they can to avoid ads.
An obvious example is the success that Google has enjoyed with Adwords. Google’s Adwords advertising system is far less intrusive than the previous favourite Internet advertising mechanism, the graphical banner ad. The fact that there are many pieces of software available whose sole purpose is to block banner ads provides another example.
The growing success of PVRs that make it quick and easy to time shift content and skip commercials also shows this trend. One of the main reasons I hear from people for downloading TV shows instead of watching them on normal TV is that it allows them to skip the commercials.
I can’t help but wonder, and hope, that we are entering an era when the Internet has reduced distribution costs to the point that news and even entertainment content will no longer need to be subsidized by advertising. At present advertisers have a lot more control over the content than most people would like to believe. News outlets may be hesitant to report something that is critical of a major advertising customer. Some TV shows have been canceled not because of lack of audience but because advertisers decided they didn’t want to buy ads during the show.
Personally, I will be quite happy to continue paying for my voice service if it means I don’t have to listen to an ad before making a call. Maybe someday I will also be able to pay for a TV show with money instead of my free time.
Last Tuesday I attended CASCON 2005. CASCON is hosted by IBM’s Centers for Advanced Studies. I have been to many technology conferences in the past such as Internet World but this was the first academic conference I have attended. As such, I don’t have anything to compare CASCON against. The conference itself seemed to be organized well. The atmosphere was very relaxed.
The keynote speech for the day was by Rob Clyde from Symantec Corp. His speech was entertaining and had lots of good statistics on the current state of computer security. Throughout the whole speech one thought kept circling in my mind, the security industry is far more worried about managing the security problems that plague computer networks than solving them. This makes sense since it is hard to sell solutions to problems that no longer exist. The moral for this story is that computer science as a discipline shouldn’t be looking to the main stream computer security industry for solutions to basic security problems.
A key part of CASCON is the technology showcase. Interested faculty and students are given small booths where they can present their current research to anyone interested. The closest analogy may be an elementary school science fair for adults. This is a great way to get some idea of what other people are currently researching and also provided me with many ideas for my own thesis topic.
Perhaps the most memorable part of my CASCON experience came after the conference was over for the day. During diner I lucked into sitting beside Dr. Morven Gentleman. A short while into the meal I discovered that among several other distinguished positions, Morven had worked at Bell Labs during the late sixties. If you know anything about the history of computing you probably know that both Unix and C were developed at Bell labs during this time. Hearing first hand anecdotes about the formative years of Unix and C was absolutely fabulous. The rest of the diner consisted of me peppering Morven with questions about the history of computing which he seemed happy to answer. Hopefully I wasn’t too annoying.
A few days ago I finally finished reading The Collapse of Globalism by John Ralston Saul. Unfortunately, I only had time to read it at the rate of about a chapter a day so I didn’t give the book as thorough of a reading at it really deserves.
Despite the somewhat sensational title I found this book to be much more balanced than I thought it would be. At several points Saul explains some of the good that has come with globalization but make no mistake, this book is about what has went wrong.
Saul believes that the ideas which drive globalism are based more on ideology than fact. This book does great service to society by tearing apart a simple ideology that will supposedly solve all of the world’s problems. Saul does not argue that all aspects of globalism are bad. He simply argues that one economic model cannot work in all situations. Pretty common sense when you think about it.
Here are couple of links to reviews of this book that are much better than mine.
http://blogs.salon.com/0002007/2005/08/04.html
http://www.timesonline.co.uk/article/0,,2102-1616368_1,00.html
For those of you reading this blog who actually know me personally you may be interested to know that I added a bunch of pictures to the Photo Album today. Most are of Barry and Mylene’s recent wedding.
I have been meaning to experiment with VoIP service for a while now. So when the Vonage sales droids called me the other day offering a free month of service I thought I would give it a go.
It only took a couple of days for the Motorola box to arrive. This box is basically a VoIP to POTS converter. Ethernet in and two POTS RJ-11 jacks out. Setup is simple, hookup the Ethernet port and plug-in a phone.
So far I am pretty impressed with the service. No one I have spoken to in the last week has said anything that would indicate the quality was different from my old POTS line. I have been able to make the quality bad by starting a large upload while talking on the phone but this is party due to my network topology. Instead of putting my home network behind the Vonage Motorola box so that it can do some QoS magic I have simply plugged it into my LAN. My home network configuration has some routing requirements that make it impossible for me to put their box out front. I’m pretty sure I can deal with this quality problem with the Linux QoS features on my router anyway.
What I like most about the service is that everything can be controlled from the Vonage website. Setting up call forwarding is as simple as typing in the phone number. No more *91, wait five seconds etc. What I like even more is that voice mail messages are accessible online. You can listen, save and delete your messages from the website.
Another nice feature is being able to take your VoIP to POTS box to any location with high speed Internet. This means your home number can now travel with you. Vonage also sells a soft phone service so that you can use a SIP client on a PC or laptop while traveling. This avoids carrying the converter around.
I haven’t decided yet if this is just an experiment or if I will be canceling my Bell POTS line but it is definitely looking good.