Network topology

its all about netwrok topology

1. Network Topology Presented by: Group of Thrunks Jericho Alcantara

2. Leader: Thrunks Jericho Alcantara Members: Eingelyn Anne Santos Noreen Reyes Marciana Domingo Aran Jade Federnales Joumeil Cotino Dominic Nabua Jerwyn Samalca Marvince Cleofas Paul Cedrick Famodulan Gerald Rodriguez

3. Network Topology In communication networks, a topology is a usually schematic description of the arrangement of a network, including its nodes and connecting lines .

4. Two basic categories of network topology: A.Physical Topology The Physical Topology of a network refers to the configuration of cables,computers, and other peripherals.

5. B. Logical topology Is the method used to pass information between workstations.

6. The star topology consists of a central node (hub, router, etc.) connecting the peripheral nodes of the network together. Each message passes through the hub and is redirected to its destination . Star Topology

7. Extended star A type of network topology in which a network that is based upon the physical star topology has one or more repeaters between the central node and the peripheral or 'spoke' nodes, the repeaters being used to extend the maximum transmission distance of the point-to-point links between the central node and the peripheral nodes beyond that which is supported by the transmitter power of the central node or beyond that which is supported by the standard upon which the physical layer of the physical star network is based.

8. Distributed Star A type of network topology that is composed of individual networks that are based upon the physical star topology connected in a linear fashion – 'daisy-chained'– with no central or top level connection point.

9. Advantages Of Star Topology: Easy to detect errors and faults in the network. Each node is separate from all other nodes, so it is easy to isolate and fix certain problems with individual nodes without affecting the rest of the network . Any break in a connection between the central and peripheral nodes does not cause a failure in the network . Minimizes the number of possible collisions .

10. Disadvantages of Star Topology: If the hub has a fault, the entire network can fail . An expensive network layout to install because of the amount of cables needed . Performance and as well number of nodes which can be added in such topology is depended on capacity of central device. The use of hub, a router or a switch as central device increases the overall cost of the network.

11. Mesh topologies present multiple paths that a message can take to reach their destination. Each node is connected to one or more other nodes. If each node is connected to every other nodes then it is called fully connected or a full mesh. Mesh Topology

12. O ccurs when every node has a circuit connecting it to every other node in a network. Full mesh is very expensive to implement but yields the greatest amount of redundancy, so in the event that one of those nodes fails, network traffic can be directed to any of the other nodes. Full mesh is usually reserved for backbone networks. Full Mesh Topology

13. Is less expensive to implement and yields less redundancy than full mesh topology. With partial mesh, some nodes are organized in a full mesh scheme but others are only connected to one or two in the network. Partial mesh topology is commonly found in peripheral networks connected to a full meshed backbone. Partial Mesh Topology

14. Advantages of Mesh Topology: Creates inherent fault protection through the redundancy in connections between nodes. There is generally multiple paths from node to node. A mesh network fault will thus generally not cause a node from being disconnected from the network . May be easy to expand. Only a small number of nodes may need to have their routing algorithms/tables updates to expand the network if the network is small, or the expansion occurs in an outlying region of the network . Troubleshooting is easy as compared with other networks.

15. Disadvantages of Mesh Topology : Can be much more complex than other topologies. As the size of a mesh network grows the number of connections can grow exponentially, with the most extreme growth rate occurring in full meshes, which have n(n-1)/2 connections . If the routing algorithm/table is not properly implemented in any number of nodes, faults can occur. For example, lost messages and messages continuously passing through a cycle . May be very difficult to expand. As highlighted in a full mesh, all nodes will need to have their routing algorithms/tables updates to include the new nodes.

16. The bus topology uses a single transmission medium which all messages are broadcasted on. Each node receives every message, but only the intended target accepts it. Only one message can be sent at a time on a bus network, otherwise a collision will occur, corrupting the message. Bus Topology

17. Linear Bus The type of network topology in which all of the nodes of the network are connected to a common transmission medium which has exactly two endpoints (this is the 'bus', which is also commonly referred to as the backbone, or trunk) – all data that is transmitted between nodes in the network is transmitted over this common transmission medium and is able to be received by all nodes in the network simultaneously.

18. Distributed Bus The type of network topology in which all of the nodes of the network are connected to a common transmission medium which has more than two endpoints that are created by adding branches to the main section of the transmission medium – the physical distributed bus topology functions in exactly the same fashion as the physical linear bus topology “(all nodes share a common transmission medium)."

19. Advantages of Bus Topology: Simple to configure . Cable length required for this topology is the least compared to other networks . Bus topology costs very less. Linear Bus network is mostly used in small networks. Good for LAN . Easy to expand joining two cables together.

20. Disadvantages of Bus Topology: A fault in the main connection medium can cause the network to fail.  Very unsafe. Each computer receives all messages on the network. A computer can still accept messages even if its address does not match the destination address leading . Is slow under heavy load, and can prone to collision problems . Cable has a limited length.

21. Ring Topology In a ring topology each node is connected to exactly two other nodes forming a closed loop. Messages are passed along the ring in a single direction until they reach their destination.

22. Dual-ring networks contain two separate rings networks which pass messages in opposite directions. Generally, only one ring is operating at a time. This creates redundancy in the network so that if one of the rings fails backup ring will allow the network to continue to function. Dual-Ring Network

23. Advantages of Ring Topology: Very orderly network where every device has access to the token and the opportunity to transmit. Performs better than a  bus topology  under heavy network load. Does not require a central node to manage the connectivity between the computers.

24. Due to the point to point line configuration of devices with a device on either side (each device is connected to its immediate neighbor), it is quite easy to install and reconfigure since adding or removing a device requires moving just two connections. Reconfiguration for line faults of bidirectional rings can be very fast, as switching happens at a high level, and thus the traffic does not require individual rerouting.

25. Disadvantages of Ring Topology: One malfunctioning workstation can create problems for the entire network. This can be solved by using a dual ring or a switch that closes off the break . Moving, adding and changing the devices can affect the network.

26. Bandwidth is shared on all links between devices . More difficult to configure than a Star: node adjunction = Ring shutdown and reconfiguration . Communication delay is directly proportional to number of nodes in the network.

27. Point to Point Topology   A   point-to-point  connection refers to a communications connection between two nodes or endpoints. An example is a  telephone call , in which one telephone is connected with one other, and what is said by one caller can only be heard by the other.

28. Point to Multipoint Is communication which is accomplished via a distinct type of one-to-many connection, providing multiple paths from a single location to multiple locations.

29. Advantages of Point to Point Topology : This network is the simplest layout for any network, and it is pretty easy to visualize. If you can imagine a network in which there are only two nodes (say, two computers, for instance), you can easily picture a point-to-point network . As you can probably guess, information on this network goes from one point to another. This transfer of data can happen in multiple ways across the network: in a single direction (sending and receiving), in both directions (full duplex), or can only send or receive in a single direction (half duplex ). This simplistic topology is very easy to set up and maintain, and it is intended for very small networks. In fact, this type of network has a major drawback in that it can only support two nodes.

30. Disadvantages of Point to Point Topology: Though there are some situations in which this type of network may be useful, most networks will probably require more than two nodes. However, for networks that don’t, this point to point topology can be a great way to set up something simple. With only two nodes, it is very easy to maintain the layout . However, there is another drawback in that since there are only two nodes, if either of the nodes stop working, information cannot be sent across the network. For example, if there are two computers in the network and one of them breaks, you cannot send or receive messages to the broken computer .

31. In order for the network to work effectively, you must replace the broken computer–and this can be both time consuming and costly. For this reason, it is important to note that while understanding how to fix a broken point to point topology can be fairly simple, the actual application of this solution can be a hindrance due to monetary and time issues.

32. Combining the characteristics of multiple star networks along a single bus network using a root node forms the tree topology. The central node of each star network is connected to the root node of the tree creating multiple tiers on the network. Messages passing between star networks pass through the root node to their destination. Tree Topology

33. Advantages of Tree Topology: Scalable as leaf nodes can accommodate more nodes in the hierarchical chain . A point to point wiring to the central hub as each intermediate node of a tree topology represents a node in the bus topology. Other hierarchical networks are not affected if one of them gets damaged. Easier maintenance and fault finding. Expansion of Network is possible and easy.

34. Disadvantages of Tree Topology: Huge cabling is needed. A lot of maintenance is needed. backbone forms the point of failure. As more and more nodes and segments are added, the maintenance becomes difficult. Scalability of the network depends on the type of cable used.

35. Hybrid Topology A  hybrid topology  is a type of network topology that uses two or more other network   topologies , including  bus topology ,  mesh topology ,  ring topology ,  star topology , and  tree topology .

36. Advantages of Hybrid Topology:   Reliable :  Unlike other networks, fault detection and troubleshooting is easy in this type of topology. The part in which fault is detected can be isolated from the rest of network and required corrective measures can be taken, WITHOUT affecting the functioning of rest of the network.  Scalable :  Its easy to increase the size of network by adding new components, without disturbing existing architecture. 

37. Flexible:  Hybrid Network can be designed according to the requirements of the organization and by optimizing the available resources. Special care can be given to nodes where traffic is high as well as where chances of fault are high.  Effective:  Hybrid topology is the combination of two or more topologies, so we can design it in such a way that strengths of constituent topologies are maximized while there weaknesses are neutralized. For example we saw Ring Topology has good data reliability (achieved by use of tokens) and Star topology has high tolerance capability (as each node is not directly connected to other but through central device), so these two can be used effectively in hybrid star-ring topology.

38. Disadvantages of Hybrid Topology: Complexity of Design:  One of the biggest drawback of hybrid topology is its design. Its not easy to design this type of architecture and its a tough job for designers. Configuration and installation process needs to be very efficient. Costly Hub:  The hubs used to connect two distinct networks, are very expensive. These hubs are different from usual hubs as they need to be intelligent enough to work with different architectures and should be function even if a part of network is down. Costly Infrastructure:  As hybrid architectures are usually larger in scale, they require a lot of cables, cooling systems, sophisticate network devices, etc.

39. That's all, Thank you !