1. How Circuit-Switched Digital
Networks Work
● Circuit switching
● The central office switch
● A switching matrix
● Fiber-optic link
● Reference

2. Circuit switching
Circuit switching is a telecommunication
technology.
The circuit functions as if the nodes were
physically connected with an electrical circuit.
The bit delay is constant during a connection,
as opposed to packed switching, where packet
queues may cause varying packet transfer
delay.

3. The central office switch
A central office switch is a large rack of
equipment located in a telephone company's
central office that switches calls locally or to
long-distance carriers over dedicated circuits.

4. A switching matrix
A switching matrix
used to connect the
current source and the
volt meter to all of the
contact points in a
cable.

5. Fiber-optic link
A fiber-optic link is a
thin, flexible,
transparent fiber.
Fibers are used instead
of metal wires because
signals travel along
them with less loss.

6. Reference
● Wikipedia
http://en.wikipedia.org/wiki/Main_Page
● MINDSPEED
http://www.mindspeed.com/web/home.html
● Cisco
http://www.cisco.com/en/US/hmpgs/index.html
● AKON
http://www.akoninc.com/index.php