Network topology is the layout pattern of interconnections of the various elements (links, nodes, etc.) of a computer or biological network.
Network topologies may be physical or logical. Physical topology refers to the physical design of a network including the devices, location and cable installation. Logical topology refers to how data is actually transferred in a network as opposed to its physical design. In general physical topology relates to a core network whereas logical topology relates to basic network.Topology can be understood as the shape or structure of a network. This shape does not necessarily correspond to the actual physical design of the devices on the computer network.
Types of Topology:
Bus Network Topology
LANs that make use of bus topology connects each node to a single cable. Some connector connects each computer or server to the bus cable. For avoiding the bouncing of signal a terminator is used at each end of the bus cable. The source transmits a signal that travels in both directions and passes all machines unless it finds the system with IP address, the intended recipient. The data is ignored in case the address is unmatched. The installation of one cable makes bus topology an inexpensive solution as compared to other topologies; however the maintenance cost is high. If the cable is broken all systems would collapse. Star Network Topology
The topology when each network host is connected to a central hub in LAN is called Star. Each node is connected to the hub with a point-to-point connection. All traffic passes through the hub that serves as a repeater or signal booster. The easiest topology to install is hailed for its simplicity to add more nodes but criticized for making hub the single point of failure. The network could be BMA (broadcast multi-access) or NBMA (non-broadcast multi-access) depending on whether the signal is automatically propagated at the hub to all spokes or individually spokes with those who are address. In local area networks with a star topology, each network host is connected to a central hub with a point-to-point connection. The network does not necessarily have to resemble a star to be classified as a star network, but all of the nodes on the network must be connected to one central device. All traffic that traverses the network passes through the central hub. The hub acts as a signal repeater. The star topology is considered the easiest topology to design and implement. An advantage of the star topology is the simplicity of adding additional nodes. The primary disadvantage of the star topology is that the hub represents a single point of failure.Ring Network Topology
Ring topology is one of the old ways of building computer network design and it is pretty much obsolete. FDDI, SONET or Token Ring technologies are used to build ring technology. It is not widely popular in terms of usability but incase if you find it any where it will mostly be in schools or office buildings.Such physical setting sets up nodes in a circular manner where the data could travel in one direction where each device on the right serves as a repeater to strengthen the signal as it moves ahead.
Mesh Topology
A network setup where each of the computers and network devices are interconnected with one another, allowing for most transmissions to be distributed, even if one of the connections go down. This topology is not commonly used for most computer networks as it is difficult and expensive to have redundant connection to every computer. However, this topology is commonly used for wireless networks.Tree Topology
Tree Topology is a combination of the bus and the Star Topology. The tree like structure allows you to have many servers on the network and you can branch out the network in many ways. This is particularly helpful for colleges, universities and schools so that each of the branches can identify the relevant systems in their own network and yet connect to the big network in some way.
A Tree Structure suits best when the network is widely spread and vastly divided into many branches. Like any other topologies, the Tree Topology has its advantages and disadvantages. A Tree Network may not suit small networks and it may be a waste of cable to use it for small networks. Tree Topology has some limitations and the configuration should suit those limitations.
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Network Types:
LAN - Local 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 LANs (perhaps one per room), and occasionally a LAN will span a group of nearby buildings. In TCP/IP networking, a LAN is often but not always implemented as a single IP subnet.
WLAN - Wireless Local Area Network
- A LAN based on WiFi wireless network technology
WAN - Wide Area Network
- As the term implies, a WAN spans a large physical distance. The Internet is the largest WAN, spanning the earth. A WAN is a geographically-dispersed collection of LANs. A network device called a router connects LANs to a WAN. In IP networking, the router maintains both a LAN address and a WAN address.
MAN - Metropolitan Area Network
- A network spanning a physical area larger than a LAN but smaller than a WAN, such as a city. A MAN is typically owned an operated by a single entity such as a government body or large corporation.
SAN - Storage Area Network, System Area Network, Server Area Network, or sometimes Small Area Network
- Connects servers to data storage devices through a technology like Fibre Channel.
CAN - Campus Area Network, Controller Area Network, or sometimes Cluster Area Network
- A network spanning multiple LANs but smaller than a MAN, such as on a university or local business campus.
PAN - Personal Area Network
- A computer network used for communication among computerized devices, including telephones and personal digital assistants. PANs can be used for communication among the personal devices themselves (intrapersonal communication), or for connecting to a higher level network and the Internet (an uplink).
DAN – Desk Area Network
- Is a multimedia workstation based around an ATM interconnect (as shown in the above diagram). All communication between peripherals and even between the CPU and its main memory is achieved by sending ATM cells through a switch fabric.
A Tree Structure suits best when the network is widely spread and vastly divided into many branches. Like any other topologies, the Tree Topology has its advantages and disadvantages. A Tree Network may not suit small networks and it may be a waste of cable to use it for small networks. Tree Topology has some limitations and the configuration should suit those limitations.
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Network Types:
LAN - Local 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 LANs (perhaps one per room), and occasionally a LAN will span a group of nearby buildings. In TCP/IP networking, a LAN is often but not always implemented as a single IP subnet.
WLAN - Wireless Local Area Network
- A LAN based on WiFi wireless network technology
WAN - Wide Area Network
- As the term implies, a WAN spans a large physical distance. The Internet is the largest WAN, spanning the earth. A WAN is a geographically-dispersed collection of LANs. A network device called a router connects LANs to a WAN. In IP networking, the router maintains both a LAN address and a WAN address.
MAN - Metropolitan Area Network
- A network spanning a physical area larger than a LAN but smaller than a WAN, such as a city. A MAN is typically owned an operated by a single entity such as a government body or large corporation.
SAN - Storage Area Network, System Area Network, Server Area Network, or sometimes Small Area Network
- Connects servers to data storage devices through a technology like Fibre Channel.
CAN - Campus Area Network, Controller Area Network, or sometimes Cluster Area Network
- A network spanning multiple LANs but smaller than a MAN, such as on a university or local business campus.
PAN - Personal Area Network
- A computer network used for communication among computerized devices, including telephones and personal digital assistants. PANs can be used for communication among the personal devices themselves (intrapersonal communication), or for connecting to a higher level network and the Internet (an uplink).
DAN – Desk Area Network
- Is a multimedia workstation based around an ATM interconnect (as shown in the above diagram). All communication between peripherals and even between the CPU and its main memory is achieved by sending ATM cells through a switch fabric.
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