Network Topology

Network topology is the study of the arrangement or mapping of the weather (links, nodes, etc.) of a network, especially the physical (real) and logical (virtual) interconnections between nodes of a networks.

Network Topology Diagram

A local area network (LAN) is one example of a network topology that exhibits both a physical topology and a logical topology.

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Basic types of Topologies

The arrangement or mapping of the weather of a network gives rise to certain basic topologies which can then be combined to make more complex topologies (hybrid topologies).

The most common of those basic type sorts of topology are:

BUS (Linear Bus, Distributed Bus) Topology

Star Topology

Ring Topology

Mesh Network Topology

Partially connected  mesh (or simply ‘mesh’)

Fully connected mesh

Tree Topology

Hybrid Topology

Point to Point Topology

Star Topology

In Star topology each device (node) is physically connected with central controller known as hub or switch, each device has a dedicated point devices are not directly connected with one another.

A Star Topology is designed with each node (file server, workstations, and peripherals) connected directly to a central Network Topology hub or concentrator.

Data on a Star Topology passes through the hub or concentrator before continuing to its destination. The hub or concentrator manages and controls all functions of the Network Topology. It also acts as a repeater for the info flow. This configuration is common with twisted pair cable; however, it also can be used with coax or fiber optic cable.

The protocols used with star configurations are usually Ethernet or Local Talk. Token Ring uses an identical topology, called The Star-Wired Ring.

Star Network Topology Diagram

Also known as a Star Topology, a star topology is one of the most common network setups where each of the devices and computers on a Network Topology connect to a central hub. A major disadvantage f this type of Topology of Network is that if the central hub fails, all computers connected of a simple computer setup on a network using the Star Topology.

The star reduces the prospect of network failure by connecting all of the systems to a central node. When applied to a bus-based network, this central hub rebroadcasts all transmissions received from any peripheral node to any or all or any or any peripheral nodes on the network, sometimes including the originating node. 

All peripheral nodes may thus communicate with all others by transmitting to, and receiving from, the central node only. The failure of a cable linking any peripheral node to the central node will end in the isolation of that peripheral node from all others, but the remainder of the systems are going to be unaffected.

Advantages of Star Topology

Star Topologies became the dominant topology type in contemporary LANs. they're flexible, scaleable, and comparatively inexpensive compared to more sophisticated LANs with strictly regulated access methods.

Stars have about made buses and rings obsolete in LAN topologies and have formed the idea for the ultimate LAN topology.

Easy to install and wire.

No disruptions to the Topology of Network when connecting or removing devices.

Easy to detect faults and to remove parts.

Performance:

Data packets don’t travel through any unnecessary nodes. Communication between any two devices on the Network Topology involves at most three devices and two links. The isolation of traffic between nodes means heavy utilization from one device is invisible to other devices on the network, as long as the central hub retains adequate capacity.

Isolation:

Each device is isolated on its own link. This makes it easy to isolate individual devices from the networks by disconnecting them from the hub. Any non-centralized failure will have very little effect on the Network Topologies.

Centralization:

The network can easily be scaled or expanded by adding to the capacity of the hub node, or by adding additional devices to the Star Network Topology. The fact that all traffic passes through the central hub means that the hub can easily e used to inspect or control traffic through the network.

Simplicity:

The topology is straightforward to know, establish, and navigate. Complex routing or message passing protocols is usually unnecessary. Individual nodes can easily be added or removed, and fault detection is simplified, as each link/device are often probed individually.

Disadvantages of Star Topology

One big disadvantage of a star is that the dependency of the entire topology on one single central controller, the hub or switch. If the hub goes down, the entire system will dead.

Many Star Network require a tool at the central point to rebroadcast or switch the network traffic. The cabling cost is more since cables must be pulled from all computers to the central hub or switch.

Ring Topology

The type of topology during which each of the nodes of the network is connected to 2 other nodes within the network and with the primary and last nodes being connected to each other, forming a ring – all data that is transmitted between nodes in the network travels form one node to the next node in a circular manner and therefore the data generally flows during a single direction only.

A Ring Network may be a topology during which each node connects to precisely two other nodes, forming a circular pathway for signals: a hoop. Data travels form node to node, with each node handling every packet.

The Ring Topology began as an easy peer-to-peer LAN topology. Each networked workstation had two connection: one to each of its nearest neighbors.

The interconnection had to make a physical loop, or Ring Topology. Data was transmitted unidirectional round the ring. Each workstation acted as a repeater, accepting and responding to packets addressed there to, and forwarding on the opposite packets to subsequent workstation “downstream.”

The original LAN Ring Network Topology featured peer-to-peer connections between workstations. These connections had to be closed – that's, that they had to make a hoop. The advantage of such LANs was that reaction time was fairly predictable. The more devices there have been within the ring, the longer the network delays.

The drawback was that early topology of ring networks could be completely disable if one of the workstations failed.

What is dbms? (What database management system)

Basic knowledge of Computer (Computer knowledge)

Because a hoop topology provides just one pathway between any two nodes, Ring Network could also be disrupted by the failure of one link. A node failure or cable break might isolate every node attached to the ring.

The ring topology of network supports coaxial cable, twisted pair cables as well as fiber optic cable. Common protocol used to implement ring topology are, token ring and Fiber Distributed Interface (FDI).

Dual-ring Topology                                                         

The type of Network Topology in which each of the nodes of the network is connected to two other nodes in the network, with tow connections to each of these nodes, and with the first and last nodes being connected to each other with tow connection, forming a double ring – the data flows in opposite directions around the two rings, although, generally, only one of the rings carries data during normal operation, and thus the 2 rings are independent unless there is a failure or break in one two rings are independent unless there's a failure or break in one among the rings, at which era the 2 rings are joined (by the stations on either side of the fault) to enable the flow of knowledge to continue employing a segment of the second ring to bypass the fault within the primary ring.

Advantages of Ring Topology

The main advantage of the ring topology is that all the computer on the networks have equal access to the token.

Very orderly network where every device has access to the token and therefore the opportunity to transmit.

Performs better than a star under heavy network load.

Can create much larger Networks using Token Ring.

Does not require network server to manage the connectivity between the computer.

A ring is comparatively easy to put in and reconfigure.

Disadvantages of Ring Topology

One malfunctioning workstation or bad port within the MAU can create problems for the whole Network Topology.

The main disadvantage of the ring topology is that adding or moving devices affects the whole network.

Network adapter cards and Mau’s are much more expensive that Ethernet cards and hubs.

Bus Topology

A bus topology may be a specification during which a group of clients are connected via a shared communications line, called a bus. There are several common instances of the bus architecture, including one within the motherboard of most computers, and people in some versions of Ethernet networks.

Bus Networks Topology are the only thanks to connect multiple clients, but often have problems when two clients want to transmit at an equivalent time on an equivalent bus.

 Thus systems which use bus network architectures normally have some scheme of collision handling or collisions avoidance for communication on the bus, fairly often using Carrier Sense Multiple Access or the presence of a bus master which controls access to the shared us resource.The bus usually used when a network installation is little, simple or temporary.

Bus Network Topology uses a broadcast channel which suggests that each one attached stations can hear every transmission and every one stations have equal priority in using the network to transmit data.

The connection between the cable and the NIC of the computer is accomplish with the T connector.

Bus Topology Network Diagram

A bus, shown in above Figure, features all networked nodes interconnected peer-to-peer employing a single, open-ended cable.

These ends must be terminated with a resistive load-that is, terminating resistors. This singe cable can support only a single channel. The cable is called the bus.

The typical bus features one cable, supported by no external electronics that interconnects all networked nodes peer to see. All connected devices hear the bussed transmissions and accept those packets addressed to them. 

The shortage of any external electronics, like repeaters, makes bus LANs simple and cheap. The downside is that it also imposes severe limitations on distances, functionality, and scalability.

This topology is impractical for all but the smallest of LANs. Consequently, today’s commercially available LAN products that use a bus topology are inexpensive peer-to-peer networks that provide basic connectivity. These products are targeted at home and small office environments.

Linear bus

The type of topology during which all of the nodes of the network are connected to a standard transmission medium which has exactly two endpoints (this is that the ‘bus’, which is additionally commonly mentioned because the backbone, or trunk) – all data that's transmitted between nodes within the network is transmitted over this common transmission medium and is in a position to be received by all nodes within the network virtually simultaneously.

A linear bus Topology consists of a main run of cable with a terminator at each end.
All nodes (file server, workstations, and peripherals) are connected to the linear cable. Ethernet and native Talk networks use a linear bus Topology.

The two endpoints of the common transmission medium are normally terminated with a tool called a terminator that exhibits the characteristic impedance of the transmission medium and which dissipates or absorbs the energy that is still within the signal to stop the signal from being reflected or propagated back on to the transmission medium within the other way, which might cause interference with and degradation of the signals on the transmission medium.

Advantages of a Linear bus Topology

Easy to connect a computer or peripheral to a linear bus.
Requires less cable than a star.

Disadvantages of a Linear bus Topology

Entire network shuts down if there's an opportunity within the main cable.
Terminators are required at both ends of the backbone cable.
Difficult to identify the matter if the entire network shuts down.
Not meant to be used as a stand-alone solution in large building.

Distributed bus Topology

The type of topology during which all of the nodes of the network are connected to a standard transmission medium which has quite two endpoints that are created by adding branches to the most section of the transmission medium – the physical distributed bus functions in just an equivalent fashion because the physical linear bus.
All of the endpoints of the common transmission medium are normally terminated with a tool called a ‘terminator’.

The physical linear bus is usually considered to be a special case of the physical distributed bus – i.e., a distributed bus with no branching segments.

The physical distributed bus is usually incorrectly mentioned as a physical tree topology - however, although the physical distributed bus resembles The Physical Tree Topology, it differs from the physical tree topology therein there's no central node to which the other nodes are connected, since this hierarchical functionality is replaced by the common bus.

Advantages of bus Topology

Easy to implement and extend
Requires less cable than a star .
Well suited for temporary or small networks not requiring high speeds (quick setup)

Disadvantage of bus Topology

Limited cable and number of stations.
If there's a drag with the cable, the whole Network Topology goes down.
Maintenance costs could also be higher within the end of the day .
Performance degrades as additional computers are added or on heavy traffic.
Proper termination is required (loop must be in closed path.)
Significant Capacitive Load (each bus transaction must be ready to stretch to most distant link.)
It works best with limited number of nodes
It is slower that the opposite topologies.

Mesh Topology

The Mesh Network Topology is typically implemented in limited area, for instance, as a backbone connecting the most computers of a hybrid network which will include several other topologies.

There are two sorts of Mesh Network Topologies as mentioned below:

Mesh Topology Diagram

Fully Connected Mesh Topology

The type of topology during which each of the nodes of the network is connected to every of the opposite nodes within the network with a point-to-point link – this makes it possible for data to be simultaneously transmitted from any single node to all or any of the opposite nodes.

The Physically fully connected Mesh Topology is usually too costly and sophisticated for practical networks, although the topology is employed when there are only slightly number of nodes to be interconnected.

The dedicated link carries traffic only between the 2 devices it connects.

Partially Connected Mesh Topology

The type of topology during which a number of the nodes of the network are connected to quite one other node within the network with a point-to-point link – this makes it possible to need advantage of variety of the redundancy that's provided by a Physically Fully Connected Mesh Topology without the expense and complexity required for a connection between every node within the network.

In most practical networks that are based upon the Physical Partially connected Mesh Topology, all of the info that's transmitted between nodes within the network takes the shortest path (or an approximation of the shortest path) between nodes, except within the case of a failure or break in one among the links, during which case the info takes an alternate path to the destination. 

This needs that the nodes of the network possess some sort of logical ‘routing’ algorithm to work out the right path to use at any particular time.

Only a couple of devices on the network are connected using the full-mesh topology and therefore the others are connecting to at least one or more devices on the network.

Advantage of a Mesh Topology

The use of dedicated links guarantees that every connection can carry its own data load, thus eliminating traffic problems.
A mesh is strong because the failure of single computer doesn't bring down the whole network.
It provides security and privacy because every message sent travels along a fanatical line.
Point to point links make fault diagnose easy.

Disadvantages of a Mesh Topology

Since every computer must be connected to each other computer installation and reconfiguration is difficult. Cabling cost is more.
The hardware required to attach each link input/output and cable is dear.

Tree  Network Topology

Tree network is generally implemented using coax because the transmission medium and broadband transmission techniques.

Also referred to as a star bus, tree topology is one among the foremost common sorts of network setups that are almost like a bus and a star.

A Tree Network Topology connects star networks to other Star Network. Below may be a visual example of an easy computer setup on a Network using the Star Topology.

Tree Network Diagram

A Tree Network combines characteristics of linear bus and Star Topologies. It consists of groups of star-configured workstations connected to a Linear Bus Topology backbone cable. Tree topologies leave the expansion of an existing network, and enable schools to configure a network to satisfy their needs. A hyper tree is an acyclic hyper graph.

A Tree Network consists of star-configured nodes connected to switches/concentrators, each connected to a Linear Bus backbone.

 Each hub/concentrator rebroadcasts all transmissions received from any peripheral node to all or any peripheral nodes on the Network Topology, sometimes including the originating node. All peripheral nodes may thus communicate with all others by transmitting Topology of Network, and receiving from, the central node only.

advantage and disadvantage of DBMS (Database management system)

 The failure of a cable linking any peripheral node to the central node will end in the isolation of that peripheral node from all others, but the remainder of the systems are going to be unaffected.

Advantages of a Tree Topology

Point-to-Point wiring for individual segments.
Supported by several hardware and software venders.
Easy to increase.
It is possible to disconnect whole branches of the network from the most structure. This makes easier to isolate a defective node.

Disadvantages of a Tree Topology

Overall length of every segment is restricted by the sort of cabling used.
If the backbone line breaks, the complete segment goes down.
More difficult to configure and wire than other Topologies.

My view about this post (Conclusion)

People who use computers need to read this post. In this you get to know everything about network topology.In today's world the network is used by all. This is a computer network. We mus have known a lot of information differently from this post. The types of computer network topology are well explained in this area. Which people seem to understand well.

Question

1. What is Network Topology?
2. What is Types of Network Topology Explain it?
3. What is Types of Network? (Only Name of Topologies)