Network Topologies by Shuaib

Bus Topology


Bus networks use a common backbone to connect all devices. A single cable, the backbone functions as a shared communication medium that devices attach or tap into with an interface connector. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message.
 
Ring Topology


In a ring network, every device has exactly two neighbors for communication purposes. All messages travel through a ring in the same direction (either "clockwise" or "counterclockwise"). A failure in any cable or device breaks the loop and can take down the entire network.
Used in school campuses and office buildings.
 
Star Topology


Many home networks use the star topology. A star network features a central connection point called a "hub" that may be a hub, switch or router. Devices typically connect to the hub with Unshielded Twisted Pair (UTP) Ethernet.
Compared to the bus topology, a star network generally requires more cable, but a failure in any star network cable will only take down one computer's network access and not the entire LAN. (If the hub fails, however, the entire network also fails.)

Tree Topology


Tree topologies integrate multiple star topologies together onto a bus. In its simplest form, only hub devices connect directly to the tree bus, and each hub functions as the "root" of a tree of devices. This bus/star hybrid approach supports future expandability of the network much better than a bus (limited in the number of devices due to the broadcast traffic it generates) or a star (limited by the number of hub connection points) alone.

Mesh Topology


Mesh topologies involve the concept of routes. Unlike each of the previous topologies, messages sent on a mesh network can take any of several possible paths from source to destination. (Recall that even in a ring, although two cable paths exist, messages can only travel in one direction.) Some WANs, most notably the Internet, employ mesh routing.
A mesh network in which every device connects to every other is called a full mesh. As shown in the illustration below, partial mesh networks also exist in which some devices connect only indirectly to others.

Examples of some organizations that use LAN, WAN, MAN, PAN.

• LAN

     Lan (local area network) is a connection of computers in one building or several buildings on the same site. since it is  a connection of computers in a smaller area, data transfer rate is faster than WAN. There are several reasons for interconnecting computers, primarily to share resources such a hardware and software. LAN is commonly used in the following organisations:

1. University computer room

2. common office- such as Valldata ltd mauritius

3. Accenture ltd

• WAN              

     WAN stands for wide area network. It is a world wide connection of computers. It is used in many work places and for many purposes. for example:

1. web design companies: Bquad ltd (mauritius)

2. Call centers: such as Mms outsourcing ltd, outremer telecom ltd, serviphony ltd        

• MAN

                 A metropolitan area network (MAN) is a large computer network that usually spans a city or a large campus. A MAN usually interconnects a number of local area networks (LANs) using  fiber-optical links, and provides up-link services to wide area networks (or WAN) and the Internet. A MAN might be owned and operated by a single organization, but it usually will be used by many individuals and organizations.

examples:

1. universities campus

2. Insurance companies such as BAI


Read more on MAN at http://www.javvin.com/protocolMAN.html

• PAN

 PAN (personal area network) is a connection of computer and devices in proximity to an individual's body.

1. It can be used by an individual at home.

2. Biomedical science for monitoring patients.
    Read more at http://www.sersc.org/journals/IJBSBT/vol2_no2/3.pdf

FTP by Michael

FILE TRANSFER PROTOCOL


FTP is a standard network protocol used to copy a file from one host to another over a TCP/IP-based network, such as the Internet.
FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server.
FTP is used with user-based password authentication or with anonymous user access.

Examples:
• My FTP
• Auto FTP Manager
• Robust FTP Client
• FTP right
• Leap FTP
• Turbo FTP

Welcoming Msg.

Hi Everyone.