Plus de 2000 entreprises impliquées, mais aussi des personnalités parmi lesquelles l’ancien ministre de l’Intérieur Charles Pasqua, et les ex-diplomates Jean-Bernard Mérimée et Serge Boidevaix : c’est une gigantesque pompe à corruption que la commission d’enquête indépendante présidée par l’ancien président de la Banque centrale américaine, Paul Volcker, s’est employée à démonter. Dans son rapport publié hier (1), elle détaille les mécanismes utilisés pour détourner le programme «Pétrole contre nourriture» mis en place par l’ONU en 1996. Bagdad s’était vu autoriser une reprise limitée de ses exportations pétrolières afin de financer l’importation de biens de première nécessité. Par ses failles, le programme a permis au régime de Saddam Hussein de capter illégalement 1,8 milliard de dollars.

Asymmetric Digital Subscriber Line

Introduction

ADSL has the distinguishing characteristic that the data can flow faster in one direction than the other, i.e., asymmetrically. Providers usually market ADSL as a service for people to connect to the Internet in a relatively passive mode: able to use the higher speed direction for the “download” from the Internet but not needing to run servers that would require bandwidth in the other direction.

For conventional ADSL, downstream rates start at 256 kbit/s and typically reach 8 Mbit/s within 1.5 km (5000 ft) of the DSLAM equipped central office or remote terminal. Upstream rates start at 64 kbit/s and typically reach 256 kbit/s but can go as high as 1024 kbit/s. The name ADSL Lite is sometimes used for the slower versions.

Note that distances are only approximations. Signal attenuation and Signal to Noise Ratio are defining characteristics, and can vary completely independently of distance (eg. non-copper cabling, cable diameter).

A newer variant called ADSL2 provides higher downstream rates of up to 12 Mbit/s for spans of less than 2.5 kilometers (8000 feet). Higher symbol rates and more advanced noise shaping are responsible for these increased speeds. ADSL2+, also referred to as ITU G.992.5, boosts these rates to up to 25 Mbit/s for spans of less than 1.5 kilometers (5000 feet). ADSL2+ also offers seamless bonding options, allowing lines with higher attenuation or lower signal to noise (SNR) ratios to be bonded together to achieve theoretically the sum total of the number of lines (i.e. up to 50Mbit/s for two lines, etc), as well as options in power management and seamless rate adaption - changing the data rate used without requiring to resynchronise.

Because of the relatively low data-rate (compared to optical backbone networks) ATM is an appropriate technology for multiplexing time-critical data such as digital voice with less time-critical data such as web traffic; ATM runs widely over ADSL technology to ensure that this remains a possibility.

ADSL service providers may offer either static or dynamic IP addressing. Static addressing is preferable for people who may wish to connect to their office via a virtual private network, for some Internet gaming, and for those wishing to use ADSL to connect a Web server.