The Debian Administrator’s Handbook

“We wanted the book to be freely available (that is under the terms of a license compatible with the Debian Free Software Guidelines of course). There was a condition though: a liberation fund had to be completed to ensure we had a decent compensation for the work that the book represents. This fund reached its target of €25K in April 2012.” Raphaël Hertzog and Roland Mas hope that you will enjoy the book.
debian-handbook.info

Seeing terror risk, US asks journals to cut flu study facts

“Ever since the tightening of security after the terrorist attacks on September 11, 2001, scientists have worried that a scientific development would pit the need for safety against the need to share information. Now, it seems, that day has come.” Denise Grady and William Broad report on moves by the US government to effectively censor influenza research.
www.nytimes.com

Airport security — this house believes that changes made to airport security since 9/11 have done more harm than good

“Spending billions to force the terrorists to alter their plans in one particular way does not make us safer. It is far more cost-effective to concentrate our defences in ways that work regardless of tactic and target: intelligence, investigation and emergency response.” Bruce Schneier debates the former head of the Transportation Security Administration, Kip Hawley, on airport security. This is from the first of Schneier’s three statements on the topic.
www.economist.com 20 March, 23 March, 28 March

Sebastian Junger remembers Tim Hetherington

“You and I were always talking about risk because she was the beautiful woman we were both in love with, right? The one who made us feel the most special, the most alive? We were always trying to have one more dance with her without paying the price.” Sebastian Junger writes after the death of photojournalist Tim Hetherington in April 2011.
www.vanityfair.com

Facebook can tell you if a person is worth hiring

“But there’s another good reason for checking out a candidate’s Facebook page before inviting them in for an interview: it may be a fairly accurate reflection of how good they’ll be at the job.” Kashmir Hill reports on a study that will be read by HR consultants the world over.
www.forbes.com

The eurozone, the ant and the grasshopper

“When the ants and the grasshoppers are distributed across the division separating surplus from deficit nations within a badly designed monetary union, the stage is set for a depression that sets all against all in a vicious spiral from which only losers can emerge.” Yanis Varoufakis explains why he thinks that countries in the euro zone can neither bail out nor be bailed out of the current crisis.
www.channel4.com

Der Anruf des Bundespräsidenten

In German
“Für alle, die keine Fans der ‘Bild’ sind, ist es schon schwer erträglich zu lernen, daß der Bundespräsident das Blatt als eine Art Verfassungsorgan behandelt. Besonders deprimierend aber ist der Umstand, daß er auch in dieser einseitigen und insgesamt übersichtlichen Kommunikation zu keinem klaren Wort fähig ist.” Nils Minkmar explores Christian Wulff‘s attitudes towards the editorial independence of the press.
www.faz.net

“German President Wulff reportedly sought to prevent tabloid Bild from publishing a damaging article about his private loan arrangements.”

The curse of TINA

“Think Tanks surround politics today and are the very things that are supposed to generate new ideas. But if you go back and look at how they rose up—at who invented them and why—you discover they are not quite what they seem.” Adam Curtis looks at the history of the Think Tank in the UK and asks why modern politics, for all its Think Tanks, seems so paradoxically short of new ideas.
www.bbc.co.uk

At 52, an exonerated man is victorious in the ring

“Four rounds in a boxing ring could not undo 26 years in prison, but Dewey Bozella made the most of them, winning a unanimous decision Saturday at the Staples Center in Los Angeles in what he says will be his only professional fight.” Peter Applebome reports on Dewey Bozella’s debut as a professional boxer. Death penalty, anyone?
www.nytimes.com

This story immediately reminds me of Rubin Carter, a man who was wrongly convicted and spent 20 years in jail.

This Dianamania is a slur on Jobs

“What the Jobs hyperbole means is that your world is no bigger than your media. Or your computer. There can’t be a more tragic expression of the internet’s self-absorption.” Following the media’s response to the death of Steve Jobs, Andrew Orlowski would like to keep things in perspective.
www.theregister.co.uk

Meanwhile, Richard Stallman is not sitting on anybody’s fence and declares Steve Jobs to have had a predominantly “malign influence on people’s computing”.

It’s the end of the web as we know it

“You can turn your back on the social networks that matter in your field and be free and independent running your own site on your own domain. But increasingly that freedom is just the freedom to be ignored, the freedom to starve.” Owing to the exponential growth of social networking, Adrian Short regards the original dream of a common information space to be under threat.
adrianshort.co.uk

For 10 years, we’ve lied to ourselves to avoid asking the one real question

“When the Israeli Prime Minister gets even the US Congress to grovel to him, the American people are not going to be told the answer to the most important and ‘sensitive’ question”. For Robert Fisk, large gaps remain in our knowledge surrounding events since 9/11.
www.independent.co.uk

Introduction to VoIP

“Clearly, the future of telephony is the Internet, for which geographic location and distance don’t matter.”
Andrew Sheppard

Voice over Internet Protocol (VoIP) enables you to use the Internet for making phone calls. Calls from one VoIP phone to another are free and long-distance calls to a landline can typically be made for the price of a local call. VoIP also enables you to receive calls anywhere you connect to the Internet.

What Do You Need?

VoIP telephony requires reliable broadband connection to the Internet with a speed of at least 128 Kbps in the upload direction. In addition, there are three different types of hardware to chose from:

1) Peripherals, such as USB handsets, are relatively cheap to buy and plug straight into your computer. Used in conjunction with suitable software, they instantly turn your computer into a VoIP telephone. The most obvious drawback to such a solution is that your computer needs to be switched on to receive incoming calls.

2) Dedicated IP telephones are generally more expensive and function as independent devices on the network. However, setting up an IP telephone behind a router/firewall with Network Address Translation (NAT) can present you with additional configuration challenges.

3) Analog telephone adapters (ATAs) connect your existing telephones to VoIP services. ATAs usually have built-in ADSL modems (Annex A or Annex B, depending on your country) and, in addition to VoIP telephony, are capable of providing the computers in your home with broadband-access to the Internet. In Europe, and probably elsewhere, the ATA currently is the best tool for Voice over IP.

Session Initiation Protocol

Like any other application on the Internet, telephony services need to communicate by an established protocol. VoIP services that use the Session Initiation Protocol (SIP) benefit from the fact that SIP was designed as an open standard. As a result, any SIP-capable device should be able to link up with any other. What this means is that everybody can call anybody else and for free.

Why Not Use Skype?

Skype is a VoIP service with more than 663 million users as of 2011. It helped start the VoIP revolution. However, Skype uses a proprietary protocol that is subject to a number of security concerns and prevents free calls to and from anyone outside of the network.

What about Vonage?

Up until 2007, Vonage held on to the top spot as the largest provider of Internet-based telephony services in the US. Unlike Skype, Vonage does employ SIP to connect your calls. But it is still very much a closed system, because Vonage require you to use their own proprietary hardware and prevent direct connections to and from other SIP-based providers.

Service Providers

Connecting a call over the Internet is the basic task of an Internet Telephony Service Provider (ITSP). Additional services, such as voicemail and incoming numbers that can be dialled from normal telephones, are often available at no extra cost.

Skype and Vonage are by no means the only culprits when it comes to selling their customers short. The fact that a service provider is using SIP to connect your calls does not always equate to a service that is open and free from artificial restrictions. In particular, beware of providers that proclaim to offer a SIP-based service but then disable the facility to call users on other networks for free.

Because dedicated SIP devices can manage up to ten different accounts simultaneously, there is no need to limit yourself to just one provider. Pick and choose to create a mix of services that best suits your telephony requirements.

Expect No Less

So what should you be looking for in a good SIP provider? The first thing to bear in mind is that when it comes to setting things up, SIP is very much like email. On signing up, a provider should issue you with a username, a password, a SIP address and information about their SIP registrar. If any of these are missing or not documented, for whatever reason, just find another provider who does not keep this information from you.

Your SIP provider should offer a gateway to the Public Switched Telephone Network (PSTN), enabling you to make calls from your internet telephone to regular landlines and mobiles. Not all providers charge the same rates, so compare their respective tariffs. Billing should be by the second, and not the nearest minute.

Often there is a telephone number that others can use to call you on your internet phone. Be sure to find out what rates apply to calls to such a number. True geographical numbers are best, as they will always be charged at the same rate as regular numbers with the same area code.

Your SIP address should work exactly as you would expect, in that anyone with a SIP device or compatible software should be able to use the Internet to call you for free. Otherwise, you might as well be using Skype or Vonage and never really experience the power of true Voice over IP telephony.