Broadband Isdn
When the ISDN was originally designed, data rates of 64 Kbps to 1.544 Mbps were sufficient to handle all existing transmission needs. As applications using the telecommunications networks advanced, however, these rates proved inadequate to support many applications. In addition, the original bandwidths proved too narrow to carry the large numbers of concurrent signals produced by a growing industry of digital service providers.
To provide for the need of the next generation of technology, an extension of ISDN, called broad band ISDN, is under study. The original ISDN is now known as narrowband ISDN (N-ISDN). B-ISDN provides subscribers to the network with data rates in the range of 600 Mbps, almost 400 times faster than the PRI rate. Technology exists to support higher rates but is not yet implemented or standardized.
Narrowband ISDN is an outcome of the logical evolution of the telephone system. Broadband ISDN, however, represents a revolution in thinking that radically alters entire aspects of communication. B-ISDN is based on o change from metal cable to fiber-optic cable of telecommunications.
The majority of current research and development in the fields of telecommunications and networking is devoted to bringing this revolution. Broadband ISDN provides two types of services they are interactive and distributive.
Interactive services are those that require two-way exchange between either two subscribers or between a subscriber and a service provider. These are of three types conversational, messaging and retrieval. Conversational services are those, such as telephone calls, that support real time exchanges (as opposed to store and forward). These real-time services can be used for telephony, video telephony, video conferencing, data transfer, and so on. Messaging services are store and forward exchanges. These services are bidirectional, meaning that all parties in an exchange use them at the same time. The actual exchange may not occur in real time. One subscriber asking another for information may have to wait for an answer, even though both parties are available at the same time. Retrieval services are those used to retrieve information from a central source, called an information center. These services are like libraries; they must allow public access and allow users to retrieve information on demand. Information is provided on demand. That is, information is not distributed unless asked for.
Quick Note: Taking the Nonsense out of looking for the right spyware remover
If you really want to take the work out of looking for that right Spyware Protection from a Spybot go to the Internet and get a Free Spybot or a Free Spybot Search and Destroy
Download, In order to prevent your vital information from being ripped from your computer get your Spybot Remover Today.
Videotex allows subscribers to select video data from an online library. The service is bidirectional because it requires action on the part of both the requester and the provider.
You really want to take the work out of looking for Protection from a lurking theif then you should get your free Spybot to protect you. Go to the Internet and get The New Spybot Search And Destroy Download or just Spybot
to prevent your vital information from being taken from you and given to someone who will steal your money or something else that you treasure so dearly.
Article Source: ArticlesBase.com - Broadband Isdn