This document discusses how circuit-switched digital networks work. It describes how a dial-up router connects to a central office switch via digital access equipment and can select connections using a preprogrammed table. It also explains that internet service providers must have high-speed connections to internet backbones to provide email and other services, and that local area networks connect computers within a small physical area like a home or office.

1. How Circuit-Switched Digital
Networks Work
● P1, index
● P2, ISDN
● P3, ISP's Provides
● P4, The telephone communicates
● P5, LAN
● P6, References.

2. The Dial up router
● Digital access equipment central office switch.
● ISDN uses a separate 16-megabit channel for
fast-call.
● The dial-up router selected from a
preprogrammed table.
●

3. ISPs Provides..
● ISPs provide free
email service.
● Each ISP must have a
high-speed
connection to one of
the major Internet
back bones.

4. The telephone communicates
● The central office switch through a high-speed
intraswitch trunk.

5. LAN
● LAN is a computer
network covering a
small physical area,
like a home, office, or
group of buildings,
such as a school , or
an airport.

6. Reference
● Wikipedia
● http://ja.wikipedia.org/wiki
● BroadBand Security, Inc.
● http://ww.bbsec.co.jp