Network Topology

Network Topology

The network consists of multiple computers connected using some kind of interface, each including one or more of the hardware interface such as a network interface card) and / or serial device for PPP networking. Each computer is supported by the network software that provides functionality the server or the client. Devices that are used to transfer data over the network of so-called media. Could include copper cables and fiber optic, or radio broadcasting. Standard cables used for the purposes of this document is 10Base T Ethernet cable category 5. This is the twisted copper cabling which appears on the surface to look similar to TV coaxial cable.Terminated at each end of the connector that is very similar to the phone's connector. The maximum segment length is 100 meters.

There are two main types of network categories:

• Server-based

• Peer to peer

In a server based network, and there are computers set up to be the primary providers of services such as file or mail server. Computers providing the service are called servers and computers that request and use a service called client computers.

In Peer-to-peer network, can different computers on the network, as did all of the clients and servers. For example, many of Microsoft Windows computers will allow the exchange of files and printing. These devices can operate both as a client and server is also referred to their peers. Many are a combination of peer-to-peer networks and server-based networks. Network operating system uses the data network protocol to communicate on the network to other computers. Network operating system support the applications on the computer. And the network operating system (NOS) and includes Windows NT, Novell NetWare, Linux, Unix and others.

Three Network Topologies

Network topology describes the method used to do the physical wiring of the network. The most important of the bus, star, and ring.

NETWORK RIDE

NETWORK RIDE
A group of two or more computer systems linked together. There are many types of computer networks, including:

Network Classification
The following list presents categories used for classifying networks.

Scale
Based on their scale, networks can be classified as Local Area Network (LAN), Wide Area Network (WAN), Metropolitan Area Network (MAN), Personal Area Network (PAN),Virtual Private Network (VPN) etc.

Connection method
Computer networks can also be classified according to the hardware and software technology that is used to interconnect the individual devices in the network, such as Optical fiber, Ethernet, Wireless LAN, Home PNA, or Power line communication.

Ethernet uses physical wiring to connect devices. Frequently deployed devices include hubs, switches, bridges and/or routers.

Wireless LAN technology is designed to connect devices without wiring. These devices use radio waves or infrared signals as a transmission medium.

Types of networks
A personal area network (PAN) is a computer network used for communication among computer devices close to one person. Some examples of devices that are used in a PAN are printers, fax machines, telephones, PDAs and scanners. The reach of a PAN is typically about 20-30 feet (approximately 6-9 meters), but this is expected to increase with technology improvements.

This is a network covering a small geographic area, like a home, office, or building. Current LAN's are most likely to be based on Ethernet technology. For example, a library may have a wired or wireless LAN for users to interconnect local devices (e.g., printers and servers) and to connect to the internet. On a wired LAN, PCs in the library are typically connected by category 5 (Cat5) cable, running the IEEE 802.3 protocol through a system of interconnected devices and eventually connect to the Internet. The cables to the servers are typically on Cat 5e enhanced cable, which will support IEEE 802.3 at 1 Gbit/s. A wireless LAN may exist using a different IEEE protocol, 802.11b, 802.11g or possibly 802.11n. The staff computers (bright green in the figure) can get to the color printer, checkout records, and the academic network and the Internet. All user computers can get to the Internet and the card catalog. Each work group can get to its local printer. Note that the printers are not accessible from outside their work group.

Typical library network, in a branching tree topology and controlled access to resources
All interconnected devices must understand the network layer (layer 3), because they are handling multiple sub nets (the different colors). Those inside the library, which have only 10/100 Mbit/s Ethernet connections to the user device and a Giga bit Ethernet connection to the central router, could be called "layer 3 switches" because they only have Ethernet interfaces and must understand IP. It would be more correct to call them access routers, where the router at the top is a distribution router that connects to the Internet and academic networks' customer access routers.
The defining characteristics of LAN's, in contrast to WANs (wide area networks), include their higher data transfer rates, smaller geographic range, and lack of a need for leased telecommunication lines. Current Ethernet or other IEEE 802.3 LAN technologies operate at speeds up to 10 Gbit/s. This is the data transfer rate. IEEE has projects investigating the standardization of 100 Gbit/s, and possibly 40 G bit/s.

Campus Area Network (CAN)
This is a network that connects two or more LAN's but that is limited to a specific and contiguous geographical area such as a college campus, industrial complex, office building, or a military base. A CAN may be considered a type of MAN (metropolitan area network), but is generally limited to a smaller area than a typical MAN. This term is most often used to discuss the implementation of networks for a contiguous area. This should not be confused with a Controller Area Network. A LAN connects network devices over a relatively short distance. A networked office building, school, or home usually contains a single LAN, though sometimes one building will contain a few small LAN's (perhaps one per room), and occasionally a LAN will span a group of nearby buildings. In a LAN is often but not always implemented
A Metropolitan Area Network is a network that connects two or more Local Area Networks or Campus Area Networks together but does not extend beyond the boundaries of the immediate town/city. Routers, switches and hubs are connected to create a Metropolitan Area Network.

Wide Area Network (WAN)
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. WAN technologies generally function at the lower three layers of the reference model: the physical layer, the data link layer, and the network layer.

Global Area Network (GAN)
Global Area networks (GAN) specifications are in development by several groups, and there is no common definition. In general, however, a GAN is a model for supporting mobile communications across an arbitrary number of wireless LAN's, satellite coverage areas, etc. The key challenge in mobile communications is "handing off" the user communications from one local coverage area to the next. In Project 802, this involves a succession of terrestrial Wireless local area networks.

protocol : The protocol defines a common set of rules and signals that computers on the network use to
communicate. One of the most popular protocols for LAN's is called Ethernet. Another popular LAN protocol for PCs is the IBM token-ring network .

architecture : Networks can be broadly classified as using either a peer-to-peer or client/server architecture.