ISDN, or Integrated Services Digital Network, is a telecommunications standard that allows digital transmission of voice and data over ordinary telephone copper wires. There are three main types of ISDN: BRI, PRI, and B-ISDN. BRI and PRI utilize two B channels for media and data, and one D channel for control signals. B-ISDN, or Broadband ISDN, is designed for high bandwidth applications like video telephony using Asynchronous Transfer Mode operating at speeds from 155 Mbps to 622 Mbps. B-ISDN is widely used today and continues to be researched to further improve data transfer rates and coverage.

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Definition of ISDN.
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How to Work?
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Types of ISDN:
 BRI- Basic Rate Interface
 PRI- Primary Rate Interface
 BISDN- Broadband ISDN
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Communication channel
 B channel : media and Data
 D channel : Data and Controlling signals

5. ISDN Netwrok

6. 
PRI also have Digital service which allows entire company to
show the main advertised phone number on every call
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PRI digitally delivers the local, long distance, Direct Inward
Dial (DID) and internet service over one 4 wire interface.
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PRI connects to PBX via PRI card

8. 
BISDN- In other words Broadband Integrated Services Digital
Network which is designed to handle high bandwidth
applications.
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Asynchronous Transfer Mode Protocol
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Data Transfer rate: 155 to 622 Mbps.

9. 
Suitable for Conversational Services such as Video telephony,
Video conference and high volume, high speed data transfer etc.
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Messaging Services which is mainly Store and forward service . It
includes voice & video mail, multimedia mail as well as traditional
electronic mail.
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Retrieval service providing access to public info. Stores, and the
information can be retrieved upon user request or demand.
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No/user control of presentation. Eg.TV broadcast, where user can
choose either to view or not in no user ctrl presentation whereas
in user ctrl presentation user can partially ctrl the broadcast.

10. 
Apps: although it differs from ISDN
standard, but plays an important role in
the future success of ISDN. Specially BISDN which is been generally aimed for
Multimedia and communication purpose.
For ex. Videophone, Low-res voice and
High-res sound etc.
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ATM: Due to improvement of ATM tech.
data transfer rate has increased to 155
Mbps. And still research is going on to
increase Coverage and Data transfer rate.
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Replacing twisted copper wire with Fiber
Optic Cables.

11. 
Throughout the presentation we have discussed about
ISDN where it has been Divided into 3 different
sections BRI, PRI and B-ISDN. Whereas amongst these
three B-ISDN is widely used and still being researched
for further improvements and updates.

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http://en.wikipedia.org/wiki/Basic_Rate_Interface
http://en.wikipedia.org/wiki/Primary_Rate_Interface#PRI_and_BRI
http://www.javvin.com/protocolATM.html
http://en.wikipedia.org/wiki/Broadband_Integrated_Services_Digital_Ne
http://www.javvin.com/protocolBISDN.html
http://www.doc.ic.ac.uk/~nd/surprise_95/journal/vol2/vm4/article2.htm
http://hea-www.harvard.edu/~fine/ISDN/future.html
Verizon: No Longer Taking Orders for ISDN Service in Northeast
Starting May 18". Talkers. March 28, 2013. Retrieved April 6, 2013.
"What is ISDN?". Southwestern Bell. Retrieved April 6, 2013