A+ class 3/9/10

Today we talked about networking. We discussed the differences of the LAN (Local Area Network) and the WAN (Wide Area Network). A LAN is what computers have connected within your home or organization. A WAN is two or more LANs connected by routers to communicate and share resources. We then started to discuss topologies. The topologies that were mentioned were the star, bus, ring, mesh and point-multipoint. Three of these we talked about. We talked about the Star topology, which are computers that are all connected to a switch. That is part of the LAN technology and the star is the most popular today. The next was the bus topology. This is a topology that is no longer used but is good to know about. On a bus, multiple computers are connected on the same coaxial cable, the components that help make this up were the T-connectors, BNC connectors, repeaters and vampire taps. The last was the ring topology. This topology was introduced by IBM. Here the computers are connected using STP (shielded Twisted Pair) and the computer communicates by the use of a token. When the computer has a token then it is the one that can “speak” in a sense. Afterwards we talked about the OSI model. This model is the foundation for networking. It consists of seven layers and they are as followed:
Layer
7- Application- Service
6 -Presentation - Decryption
5 -Session - Point to point
4 -Transport -Segmentation
3 -Network - Router
2 -Data-Link -NIC
1 -Physical -Switch