This is only one of many solutions that could be used in the given scenario. The following material will identify some of the technologies that would or could be involved.
Internet
The Internet is the largest network in the world. This includes commercial (.com or .co), university (.ac or .edu) and other research networks (.org, .net) and military (.mil) networks and span many different physical networks around the world with various protocols, primarily the Internet Protocol.
Until the advent of the World Wide Web, the Internet was almost entirely unknown outside universities and corporate research departments and was accessed mostly via command line interfaces such as telnet and FTP. Since then it has grown to become an omnipresent and obligatory aspect of modern information systems.
While the web is the best known aspect of the Internet, there are many other protocols in use, supporting applications such as electronic mail, Usenet, chat, remote login, and file transfer.
Wireless networking
The term wireless networking refers to technology that enables two or more computers to communicate using standard network protocols, but without network cabling. Strictly speaking, any technology that does this could be called wireless networking. The current buzzword however generally refers to wireless LANs. This technology, fuelled by the emergence of cross-vendor industry standards such as IEEE 802.11, has produced a number of affordable wireless solutions that are growing in popularity with business and schools as well as sophisticated applications where network wiring is impossible, such as in warehousing or point-of-sale handheld equipment.
Wireless networking hardware requires the use of underlying technology that deals with radio frequencies as well as data transmission. The most widely used standard is 802.11 produced by the Institute of Electrical and Electronic Engineers (IEEE). This is a standard defining all aspects of Radio Frequency Wireless networking.
Network Topologies
A network topology describes the configuration of a network (how the network components are connected together). There are FOUR main topologies.
1. Star
The star topology uses a central hub through which all components are connected. In a computer network, the central hub is the host computer, and at the end of each connection is a terminal. A star network uses a significant amount of cable (each terminal is wired back to the central hub, even if two terminals are side by side). All routing decisions are made by the central hub, and all other workstations can be simple. An advantage of the star topology is failure in one of the terminals does not affect any other terminal, how-ever; failure of the central hub affects all terminals.
2. Ring
The ring topology connects workstations in a closed loop. Each terminal is connected to two other terminals (the next and the previous), with the last terminal being connected to the first. Data is transmitted around the ring in one direction only; each station passing on the data to the next station till it reaches its destination.
Faulty workstations can be isolated from the ring. When the workstation is powered on, it connects itself into the ring. When power is off, it disconnects itself from the ring and allows the information to bypass the workstation. Information travels around the ring from one workstation to the next. Each packet of data sent on the ring is prefixed by the address of the station to which it is being sent to. When a packet of data arrives, the workstation checks to see if the packet address is the same as its own. If it is, it grabs the data in the packet. If the packet does not belong to it, it sends the packet to the next workstation in the ring.
Ring systems use 4 pair cables (separate send/receive). The common implementation of this topology is token ring. A break in the ring causes the entire network to fail. Individual workstations can be isolated from the ring.
3. Bus
The bus topology connects workstations using a single cable. Each workstation is connected to the next workstation in a point to point fashion. All workstations connect to the same cable. If one workstation becomes inoperable, all workstations are affected. Workstations share the same cable for the sending and receiving of information. The cabling cost of bus systems is the least of all the different topologies. Each end of the cable is terminated using a special terminator. The common implementation of this topology is Ethernet. A message transmitted by one workstation is heard by all the other workstations.
4. Mesh
The mesh topology connects all computers to each other. The cable requirements are high, but there are redundant paths built in. Any failure of one computer allows all others to continue, as they have alternative paths to other computers.
Mesh topologies are used in critical connection of host computers (typically telephone exchanges). Alternate paths allow each computer to balance the load to other computer systems in the network by using more than one of the connection paths available.
Networking Hardware
Switch
A switch is a device that provides a central connection point for cables from workstations, servers, and peripherals. In a star topology, twisted-pair wire is run from each workstation to a central switch/hub. Most switches are active, that is they electrically amplify the signal as it moves from one device to another. Switches no longer broadcast network packets as hubs did in the past, they memorize addressing of computers and send the information to the correct location directly. Switches allow for multiple collision domains. Whereas a hub provided bandwidth that was shared between all devices, a switch allows each device to communicate with the full configured bandwidth.
Router
A router translates information from one network to another. Routers select the best path to route a message, based on the destination address and origin. The router can direct traffic to prevent head-on collisions, and is intelligent enough to know when to direct traffic along alternate paths. While bridges know the addresses of all computers on each side of the network, routers know the addresses of computers, bridges, and other routers on the network. Routers can even "listen" to the entire network to determine which sections are busiest -- they can then redirect data around those sections until they clear up.
Routing
Routing can be considered to be either static or dynamic. In static routing a system administrator can sets manual routes for the network. This type of configuration can reduce traffic overhead. It allows the internet administrator to specify the information about the network.
Dynamic routing performs the same function as static routing except it is more robust. Dynamic routing allows routing tables in routers to change as the possible routes change.
There are three types of dynamic routing protocol techniques;
Distance vector (RIP, IGRP)
Link state (OSPF, BGP, EGP)
Hybrid (IS-IS, EIGRP)
Distance-Vector Routing
The distance-vector routing is a type of algorithm used by routing protocols to discover routes on an interconnected network. The primary distance-vector routing algorithm is the Bellman-Ford algorithm. Distance-vector routing refers to a method for exchanging route information. A router will advertise a route as a vector of direction and distance. Direction refers to a port that leads to the next router along the path to the destination, and distance is a metric that indicates the number of hops to the destination, although it may also be an arbitrary value that gives one route precedence over another. Internetwork routers exchange this vector information and build route lookup tables from it.
Link-State Routing
Link-state routing is now the preferred routing method for most organizations and Internet service providers. Link-state routing also responds faster to changes in the network. The most important concept for link-state routing is that routers gather information about routes over the entire network. Link-state routers gather this information from neighbors and pass it on to other neighbors. Eventually, all the routers have information about all the links on the network. Then, each router runs the Dijkstra shortest path algorithm to calculate the best path to each network and create routing tables. Routes can be based on the avoidance of congested areas, the speed of a line, the cost of using a line, or various priorities.
Any or all of these technologies can be used or combined together to create a viable networking solution. The primary tool for network design is information. Surveys and inventories must be used to establish the parameters and constraints of the network. These might include labor, economic, social, time, and space issues; as well as the need to support legacy technologies.
References
Network Design retrieved January 18, 2006, from
Applying the Principles of Network Design retrieved January 18, 2006, from
Internet retrieved January 18, 2006, from
Introduction to LAN Protocols retrieved January 18, 2006, from
LAN Topologies retrieved January 18, 2006, from
How Wi-Fi Works retrieved January 18, 2006, from
Wireless LAN Technology retrieved January 18, 2006, from
Routing Protocols retrieved January 18, 2006, from
Ultimate Guide to Networking: Part One retrieved January 18, 2006, from
http://www.hardwarecentral.com/hardwarecentral/tutorials/158/4/
