Laboratory
work 2
This
week I would like you to investigate the properties of Asynchronous Time
Division Multiplexing
Use
the Internet to do this.
What
is a T-1 carrier?
· T carrier (T-1 Carrier) -- In North America, the system that uses time division multiplexing to carry 24 digital voice or data channels, each at 64 kb/s, over copper wire.
How
many 64 Kbit/ sec voice (or data) channels can it carry simultaneously?
·
24
What
is its maximum data rate?
·
1.544
Mb/s, or the DS1 rate
What
cabling types may be used to carry the T-1?
·
Copper,
FO
What
is the data rate of DS-1?
·
1.544
Mb/s
What
is the data rate of DS-3?
·
44.736
Mb/s rate consisting
How
many DS-1s can a DS-3 carry?
·
28
DS1s and associated overhead
What
does PDH stand for?
·
Plesiochronous
Digital Hierarchy
What
does SDH stand for?
·
Synchronous
Digital Hierarchy
Where
is SDH used?
·
Europe
What
does SONET stand for?
·
Synchronous
Optical Network
Where
is SONET used?
·
North
America
What
is the medium used for transmission in both SONET and SDH?
·
FO
What
types of traffic are the two ideally suited for?
·
Any,
but isochronous is best suited
Visit
http://www.infowin.org/ACTS/ANALYSYS/GENERAL/ACTS97/GUIDE/annex1.htm
and make a note of the acronyms
What
are the 5 concepts behind ATM networks (see http://shell.rmi.net/~djcline/wp3net.html
)
·
Virtual
circuits,
·
Fixed-size
packets,
·
Small
packet size,
·
Statistical
multiplexing,
·
Integrated
services.
Summarise
each of these concepts in YOUR OWN WORDS
·
Virtual
circuits map a route from the source to the destination, like telephone
network.
·
Fixed-sized
packets or cells are used to simplify buffer hardware, simplify line
scheduling, and build large parallel switches. The Internet allows packets of
varying size. Small packet sizes allow the transmitter to digitize voice
samples quickly and transmit across the network. This is designed to
accommodate the telephone network, but large files on the Internet may suffer
damage if they carved up and fit into small packets.
·
Statistical
multiplexing allows packets to be stored and forwarded, like the Internet.
·
Integrated
services means the ATM can carry voice, video and data in one network. The
telephone network doesn't do this, and the Internet doesn't do it very well,
yet