23-03-2012, 04:45 PM
Multimedia Communications
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Network Topologies Evolution
LAN
A LAN is a high-speed data network that covers a relatively small geographic area. eg. home, office etc
LANs offer computer users many advantages, including shared access to devices and applications, file exchange between connected users, and communication between users via electronic mail and other applications.
LAN data transmissions fall into three classifications: unicast, multicast, and broadcast.
LAN Topologies: bus, ring, star, and tree.
BUS TOPOLOGY
Bus networks: A bus network topology is a network architecture in which a set of clients are connected via a shared communications line, called a bus.
Bus networks are the simplest way to connect multiple clients, but often have problems when two clients want to transmit at the same time on the same bus.
Thus systems which use bus network architectures normally have some scheme of collision handling or collision avoidance for communication on the bus, quite often using Carrier Sense Multiple Access
WAN
A WAN is a data communications network that covers a relatively broad geographic area i.e., any network whose communications links cross metropolitan, regional, or national boundaries .
Point-to-Point Links: A point-to-point link provides a single, pre-established WAN communications path from the customer premises through a carrier network, such as a telephone company, to a remote network