Neowin.net

Microsoft late Wednesday night shipped the first public beta of its Active Directory "light" and will release the final code of the application-specific directory by the end of the month, according to company officials.

Active Directory Application Mode (ADAM) is designed to be a stand-alone version of the directory dedicated to a single application and maintained separate from a corporation's core Active Directory. ADAM is based on the Lightweight Directory Access Protocol (LDAP) and is an alternative to the standard full install of Active Directory, which is known as a network operating system (NOS) directory because of its tie-in with the Windows server operating system.

ADAM will provide corporate users a directory for Web-based and other applications and a place to store data specific to those applications so it cannot compromise the security or stability of their core corporate directory. While ADAM is deployed independent of the NOS directory it can tap into user authentication services offered by the NOS Active Directory or NT 4.0's NTLM technology.

News source: Infoworld.com

TCP breaks down large files into small packets of about 1500 bytes, each carrying the address of the sender and the recipient. The sending computer transmits a packet, waits for a signal from the recipient that acknowledges its safe arrival, and then sends the next packet.

If no receipt comes back, the sender transmits the same packet at half the speed of the previous one, and repeats the process, getting slower each time, until it succeeds.

This means that even minor glitches on the line can make a connection very sluggish. Because Fast TCP uses the same packet sizes as regular TCP, the hardware that carries messages around the net will still work. The difference is in software and hardware on the sending computer, which continually measures the time it takes for sent packets to arrive, and how long acknowledgements take to come back.

This reveals the delays on the line, giving early warnings of likely packet losses. The Fast TCP software uses this to predict the highest data rate the connection can support without losing data.

Since the packets are the same size as those used in TCP, none of the equipment along the internet itself will have to be modified, and no new hardware will be needed on computers receiving the data.

The first practical test of Fast TCP took place in November at a supercomputing conference. Researchers from Caltech, Stanford and CERN near Geneva in Switzerland, sent data 10,000 kilometres from Sunnyvale, California, to CERN at an average rate of 925 megabits per second. Ordinary TCP managed just 266 megabits per second on the same routes.

By ganging 10 Fast TCP systems together, the researchers have achieved transmission speeds of over 8.6 gigabits per second, which is more than 6000 times the capacity of ordinary broadband links.