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مشاهدة النسخة كاملة : What is ISDN ??



A7med Baraka
10-08-2008, 03:40 PM
What is ISDN? (http://www.barakasoft.com/vb)



ISDN stands for Integrated Services Digital Network. It is a set of standards used to digital transmission of voice and data over already existing telephone line. The ISDN uses the multiplexing technique to carry three or more data signals at once through the telephone line. The data transfer speed of ISDN line is very fast than old dial-up connection. ISDN connections are more useful in applications like videoconferencing, to run online movies and upload and download heavy files. In ISDN line, both ends of connections require the ISDN modem and a special telephone set for voice communication.
Basically ISDN divides its total bandwidth into three channels. The basic two channels send data at the speed of 64 Kbps and third one at the speed of 16 Kbps. The 64 kbps channels carry data, voice, image and movies and 16 Kbps channels carry single information and link management data. A computer connected to ISDN service can use both channels. ISDN is twice as fast than a dial-up connection but not much expensive. Its data transmission speed is up to 128 Kbps.
DSL is much easier to install and provides much faster data transfer rate. ADSL connections are more useful in applications like videoconferencing, to run online movies and upload and download heavy files. This connection is ideal for today business requirements.

Namouly4Ever
12-15-2008, 05:41 AM
شكرا يا مان هتفيدنا جدااا قسم الشبكات