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W
WAN
WAN stands for
wide area network. WANs are essentially interconnected LANs or MANs. They
can be homogeneous, interconnecting like networks, but are often
heterogeneous, that is, interconnecting LANs or MANs that have been built
using different technologies. A WAN can span campuses, cities, states, or
even continents. Typically, only one node on each LAN or MAN, called a
gateway, connects to the WAN. Other nodes communicate with the WAN via the
gateway.
Well-Known Ports The Well Known Ports are assigned by the IANA and on most systems can only be used by system (or root) processes or by programs executed by privileged users. Ports are used in the TCP [RFC793] to name the ends of logical connections which carry long term conversations. For the purpose of providing services to unknown callers, a service contact port is defined. The range for assigned ports managed by the IANA is 0-1023. The port numbers are divided into three ranges: the Well Known Ports, the Registered Ports, and the Dynamic and/or Private Ports. · The Well Known Ports are those from 0 through 1023. · The Registered Ports are those from 1024 through 49151 · The Dynamic and/or Private Ports are those from 49152 through 65535
Wide Area Network
See
WAN.
Windowing
Windowing is also
referred to as a sliding window. Windowing allows multiple PDUs (protocol
data units) to be sent at one time. If a receiving station allocates seven
input buffers it can accept seven PDUs. To keep track of the acknowledged
PDUs each is labeled with a sequence number from 0 to 7. The receiving
station acknowledges receipt of a PDU by sending the number of the next PDU
expected. If two stations are sending and receiving data, two windows must
be maintained, one for transmit and one for receive. Acknowledgments and
data can be sent together; this is known as "piggybacking."
Wireless LANs
Over
the past few years a new trend in local area networking has developed. This
new technology is typically referred to as wireless local area networks
(WLANs) but is also referred to as local area wireless networks (LAWNs).
WLANs are identical to other LANs with the exception that data is
transmitted and received without the need for wires. A great deal of work
is being done by groups such as the IEEE 802.11 committee to develop
standards and protocols which will enhance the growth and development of
this technology. Since more and more people have accepted the convenience
of cellular phones, it is believed that people will also see the benefit of
linking portable computers through such networks.
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