1_1. CN introduction.ppt
- 1. Introduction to Computer Network (CSE-301)
- 2. Books: Text Book(s): A.S. Tanenbaum, Computer Networks, Pearson Education Reference Book(s): Forouzen, "Data Communications and Networking", McGraw Hill W. Stallings, Data and Computer Communication, Macmillan Press
- 8. GOALS OF NETWORKING Resource and load sharing Programs do not need to run on a single machine Reduced cost Several machines can share printers, tape drives, etc. High reliability If a machine goes down, another can take over Mail and communication
- 9. Applications E-mail Searchable Data (Web Sites) E-Commerce News Groups Internet Telephony (VoIP) Video Conferencing Chat Groups Instant Messengers Internet Radio
- 11. Definitions: LAN -- Local Area Network Popular technologies are Ethernet -- 10 Mbps (mega bits/second) Token Ring -- 4 and 16 Mbps FDDI (Fiber Distributed Data Interface) -- 100 Mbps WAN -- Wide Area Network Usually leased telephone lines Slower than LANs MAN -- Metropolitan Area Network Usually co-axial cable (similar to cable TV)
- 12. Continue…. Host -- a computer on a network Router -- A host connected to two networks that can forward network messages from one network to another User -- A human that logs into a host Networking Application -- Software that provides service over the network. Networking applications generally interface with the Transport Layer.
- 13. Types of Networks 1. Personal Area Network (PAN) The smallest and most basic type of network, a PAN is made up of a wireless modem, a computer or two, phones, printers, tablets, etc., and revolves around one person in one building. These types of networks are typically found in small offices or residences, and are managed by one person or organization from a single device.
- 27. Campus Area Network (CAN) Larger than LANs, but smaller than metropolitan area networks (MANs, explained below), these types of networks are typically seen in universities, large K-12 school districts or small businesses. They can be spread across several buildings that are fairly close to each other so users can share resources
- 28. Storage-Area Network (SAN) As a dedicated high-speed network that connects shared pools of storage devices to several servers, these types of networks don’t rely on a LAN or WAN. SANs can be accessed in the same fashion as a drive attached to a server. Types of storage-area networks include converged, virtual and unified SANs.
- 29. Virtual Private Network (VPN) By extending a private network across the Internet, a VPN lets its users send and receive data as if their devices were connected to the private network – even if they’re not. Through a virtual point-to-point connection, users can access a private network remotely.
- 35. Network Topology The network topology defines the way in which computers, printers, and other devices are connected. A network topology describes the layout of the wire and devices as well as the paths used by data transmissions.
- 36. Bus Topology Commonly referred to as a linear bus, all the devices on a bus topology are connected by one single cable.
- 38. Star & Tree Topology The star topology is the most commonly used architecture in Ethernet LANs. When installed, the star topology resembles spokes in a bicycle wheel. Larger networks use the extended star topology also called tree topology. When used with network devices that filter frames or packets, like bridges, switches, and routers, this topology significantly reduces the traffic on the wires by sending packets only to the wires of the destination host.
- 41. Ring Topology A frame(token) travels around the ring, stopping at each node. If a node wants to transmit data, it adds the data as well as the destination address to the frame. The frame then continues around the ring until it finds the destination node, which takes the data out of the frame. Single ring – All the devices on the network share a single cable Dual ring – The dual ring topology allows data to be sent in both directions.
- 43. Mesh Topology The mesh topology connects all devices (nodes) to each other for redundancy and fault tolerance. It is used in WANs to interconnect LANs and for mission critical networks like those used by banks and financial institutions. Implementing the mesh topology is expensive and difficult.