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Prince Mohammed bin Fahd University
COEN 4331 Network Theory
Sec: 201
Name: Zainab Al-Mabuk
ID: 200800942
10-2-2013
Assignment: WAN Technologies.
A WAN is a data communications network that covers a relatively broad geographic area
and that often uses transmission facilities provided by common carriers, such as
telephone companies. WAN technologies generally function at the lower three layers of
the OSI reference model: the physical layer, the data link layer, and the network layer. It
has different technologies such as:
Circuit switching:
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Seeking out and establishing a physical copper path from end-to-end [historic
definition
•
Circuit switching implies the need to first set up a dedicated, end-to-end path for
the connection before the information transfer takes place.
•
Once the connection is made the only delay is propagation time.
Packet switching:
•
A store-and-forward network where the block of transfer is a complete packet. A
packet is a variable length block of data with a tight upper bound.
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Using packets improves mean message delay.
A setup stage is used to determine the end-to-end path before a
connection is established.
Frame relay:
Frame relay is a telecommunication service designed for cost-efficient data transmission
for intermittent traffic between local area networks LANs and between end-points in a
wide area network WAN Frame relay puts data in a variable-size unit called a frame and
leaves any necessary error correction (retransmission of data) up to the end-points, which
speeds up overall data transmission.
ATM
ATM (asynchronous transfer mode) is a dedicated-connection switching technology that
organizes digital data into 53-byte cell units and transmits them over a physical medium
using digital signal technology. Individually, a cell is processed asynchronously relative
to other related cells and is queued before being multiplexed over the transmission path.