A computer network connects multiple devices together to share resources and information. There are different types of networks including LANs, WANs, MANs, PANs, and VPNs. Network topology describes how devices are physically connected, with common topologies being bus, star, ring, mesh, and tree. Key networking hardware includes network interface cards, hubs, switches, bridges, and routers. Networks are measured based on latency, data transfer rate, bandwidth, and other performance parameters. Ethernet is a common standard used to connect devices via cables or wirelessly. IP addresses identify devices on the Internet or private networks.

1. COMPUTER NETWORKING

3. In other words networking can be defined as inter-connection of two or more computers for sharing the resources(hardware and software)and provide security on them.

5. WAN (WIDE AREA NETWORK)

6. MAN (METROPOLITAN AREA NETWORK)

7. PAN (PERSONAL AREA NETWORK)

8. VPN (VIRTUAL PRIVATE NETWORK)

9. CAN (CAMPUS AREA NETWORK)

10. GAN(GLOBAL AREA NETWORK)

12. LANs in turn may be plugged into larger networks, such as larger LANs or wide area networks (WANs), connecting many computers within an organization to each other and/or to the Internet.

13. Typically, connected devices share the resources of a single processor or server within a small geographic area (for example, within an office building).

15. WAN is a network that uses routers and public communications links.

16. The largest and most well-known example of a WAN is the Internet. A WAN is a data communications network that covers a relatively broad geographic area (i.e. one city to another and one country to another country) and that often uses transmission facilities provided by common carriers, such as telephone companies.

18. Routers, switches and hubs are connected to create a metropolitan area network.

19. The term is applied to the interconnection of networks in a city into a single larger network (which may then also offer efficient connection to a wide area network).

21. Examples of devices that are used in a PAN are :printers, fax machines, telephones, PDAs and scanners.

24. A VPN may have best-effort performance, or may have a defined service level agreement (SLA) between the VPN customer and the VPN service provider. Generally, a VPN has a topology more complex than point-to-point.

28. STAR TOPOLOGY

29. RING TOPOLOGY

30. MESH TOPOLOGY

31. STAR BUS TOPOLOGY

39. All stations have equal access.

41. Failure of one computer may impact others .

43. All the computers must have adequate number of interfaces for the connections to be made. Because of this requirement the installations is somewhat difficult.

46. It consists of groups of star-configured workstations connected to a linear bus backbone cable.

50. In addition, some method of connecting these building blocks is required, usually in the form of galvanic cable .

52. REPEATERS

53. NETWORK HUB

54. NETWORK BRIDGE

55. NETWORK SWITCH

59. When a packet arrives at one port, it is copied unmodified to all ports of the hub for transmission.

62. Bridges do not promiscuously copy traffic to all ports, as hubs do, but learn which MAC addresses are reachable through specific ports.

63. Once the bridge associates a port and an address, it will send traffic for that address only to that port.

65. Remote bridges: Can be used to create a wide area network (WAN) link between LANs. Remote bridges, where the connecting link is slower than the end networks, largely have been replaced by routers.

67. Strictly speaking, a switch is not capable of routing traffic based on IP address which is necessary for communicating between network segments or within a large or complex LAN.

68. A switch normally has numerous ports, with the intention being that most or all of the network is connected directly to the switch, or another switch that is in turn connected to a switch. Switch is a marketing term that encompasses routers and bridges, as well as devices that may distribute traffic on load or by application content.

70. Coordination between processes running on different nodes .

71. Remote I/O Devices .

72. Remote Data/File Access .

73. Personal communications (like e-mail, chat, audio/video conferencing).

75. delay introduced by the sender software.

76. delay introduced by the receiver software.

77. delay in accessing the network.

78. delay introduced by the network.

79. Data transfer rate: is the speed at which data can be transferred between sender and receiver in a network, once transmission has begun. (bit/sec) .

80. Message transfer time = latency + (length of message) / (Data transfer rate).

81. Bandwidth: is the total volume of traffic that can be transferred across the network.

82. Max. data rate (bit/sec) = carrier BW · log2 (1 + (signal/noise)) .This maximum (Shannon's Limit) is theoretical, not reachable in practice.

85. It's a standard for Media Access Control (MAC) sub layer.

86. Data transmission rate : 10 Mbits/s (Fast Ethernet reaches 100 Mbit/s).

87. High-speed driver on the computers connected by coax or UTP cables.

88. Uses a bus (10base2, coax, max. distance 200 mts) or a star (10baseT, UTP, max. 100 mts) topology.

90. Broadcast frames to all the stations on the network.

91. All stations are continually listening to the bus looking for frames addressed to them .

92. Variable length frames:64 to 1518 bytes.

94. Each network interface card attached to the Internet mast have an unique IP address.

95. The IP address can be splitted in two parts:

96. Network.

98. Thank you