Isdn
ISDN
ISDN
By Thomas A. Fine, (fine@cis.ohio-state.edu) ABSTRACT: Described here are the basics of ISDN, including much pracitical information for the consumer, as well as some fairly technical descriptions of ISDN, and finally some discussion on where ISDN is going in the future.
Table of Contents q ISDN Overview r r r r
Motivation and History What is IDSN? B-IDSN Fitting things together Access Interfaces Provided The ISDN Reference Configurations Your house's network (S/T reference points) Talking to the phone company (U reference point) Signaling Switching Bearer Services Rate Adaption Inverse Multiplexing
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All about Narrowband ISDN r r r r r r r r r
q q q q
National ISDN A little bit about Broadband ISDN ISDN References ISDN Glossary
http://www.cis.ohio-state.edu/~jain/cis788-95/isdn/index.html (1 of 18) [2/7/2000 11:11:14 AM]
ISDN
ISDN Overview
Motivation and History
A long time ago, the entire telephone network was analog. This was bad, because as a voice went farther down the line, and through more switches, the quality became worse and worse as noise crept in. And there was no way to eliminate the noise, no way to know what the signal was supposed to be. Digital encoding promised a way to encode the audio such that you'd know what the signal was supposed to be. As noise crept in, you could eliminate it throught the phone network, assuming it wasn't worse than the variation between different digital encoding levels. With the transistor revolution, this theory became possible, and the phone companies began converting their own networks over to digital. Today, you have to search pretty hard to find a phone company switch that isn't digital. They call their network the Integrated Digital Network, or IDN. This solved many of the phone company's problems. However for a variety of reasons, it has been attractive to make the phone network completely digital, from end to end. For computer users, this is ideal, because we can
ISDN
By Thomas A. Fine, (fine@cis.ohio-state.edu) ABSTRACT: Described here are the basics of ISDN, including much pracitical information for the consumer, as well as some fairly technical descriptions of ISDN, and finally some discussion on where ISDN is going in the future.
Table of Contents q ISDN Overview r r r r
Motivation and History What is IDSN? B-IDSN Fitting things together Access Interfaces Provided The ISDN Reference Configurations Your house's network (S/T reference points) Talking to the phone company (U reference point) Signaling Switching Bearer Services Rate Adaption Inverse Multiplexing
q
All about Narrowband ISDN r r r r r r r r r
q q q q
National ISDN A little bit about Broadband ISDN ISDN References ISDN Glossary
http://www.cis.ohio-state.edu/~jain/cis788-95/isdn/index.html (1 of 18) [2/7/2000 11:11:14 AM]
ISDN
ISDN Overview
Motivation and History
A long time ago, the entire telephone network was analog. This was bad, because as a voice went farther down the line, and through more switches, the quality became worse and worse as noise crept in. And there was no way to eliminate the noise, no way to know what the signal was supposed to be. Digital encoding promised a way to encode the audio such that you'd know what the signal was supposed to be. As noise crept in, you could eliminate it throught the phone network, assuming it wasn't worse than the variation between different digital encoding levels. With the transistor revolution, this theory became possible, and the phone companies began converting their own networks over to digital. Today, you have to search pretty hard to find a phone company switch that isn't digital. They call their network the Integrated Digital Network, or IDN. This solved many of the phone company's problems. However for a variety of reasons, it has been attractive to make the phone network completely digital, from end to end. For computer users, this is ideal, because we can