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Introduction to Telecommunication Systems (Continued). Telecommunication Devices Concentrators. Local Access Network. Concentrators/multiplexers can interconnect local access networks and an existing WAN Local Access Network (LACN) A LACN is more than a LAN
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Introduction to Telecommunication Systems(Continued) Telecommunication Devices Concentrators
Local Access Network • Concentrators/multiplexers can interconnect local access networks and an existing WAN • Local Access Network (LACN) • A LACN is more than a LAN A regional network that connects end-user nodes (e.g., PC, Workstation, LAN) among themselves, and to an existing wide area network
IntroductionCritical Needs in End-User Computing • Most end-users want access to Internet and/or communicate with one another. • An imperative need to support full connectivity among end-user nodes and an existing WAN.
Ethernet Outgoing Traffic Mainframe (LAN) FDDI (LAN) Token ring Remote users IntroductionConnectivity Among End-user Nodes
LACN LACN LACN LACN WAN LACN LACN LACN LACN LACN LACN Network DesignHow to support full connectivity? • Design the most economic internetwork between “end-user nodes” and an existing WAN
A direct connection to a WAN backbone node Connection via concentrators LACN LACN LACN LACN LACN LACN LACN LACN LACN LACN LACN LACN Network DesignFind an economic internetworking solution
Capacity Constraints • Port Capacity Constraint • Processing Capacity Constraint
Network Design ManagementHow to design a feasible and economical internetwork? • Find an optimal number of concentrators to interconnect all given LACN nodes to some backbone nodes on an existing WAN such that ... • All LACN nodes are connected • LACN communication requirements are satisfied • Capacity constraints on each concentrator is not violated • Total internetworking costs are minimized
Major Cost Components • Acquisition and installation costs of a concentrator • Cost of high bandwidth link between concentrator and backbone node • Cost of low bandwidth link between end-user node and concentrator