16. OSI model: The Open Systems Interconnection (OSI) model is a reference tool for understanding data communications between any two networked systems. It divides the communications processes into seven layers. Each layer both performs specific functions to support the layers above it and offers services to the layers below it. The three lowest layers focus on passing traffic through the network to an end system. The top four layers come into play in the end system to complete the process.
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19. LAYERED APPOACH: It address all the process required for effective communication and divides these process into logical groupings called layers.
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29. Ipv4 subnetting: class Range Network ID Host ID NO. of networks (subnet) NO. of address Class A 0 -- 127 N.H.H.H 0.H.H.H 2^7=128 2^24-2= 16,777,214 Class B 128 -- 191 N.N.H.H 0.0.H.H 2^14=16,384 2^16-2= 65,534 Class C 192 -- 223 N.N.N.H 0.0.0.H 2^21=2,097,152 2^8-2= 254
96. pc pc Router 1 Router 2 10.1.0.0/24 10.3.0.0/30 20.1.0.0/30 10.1.2.0/24 Destination 10.1.0.0/24 10.3.0.0/30 10.1.2.0/24 20.1.0.0/30 Next hop Direct Direct R2 R2
123. Front panel indicator: Highly visible status indicator Receiver power display Graphical high-resolution LCD display 5 way cursor control and numerical entry