Network Topologies are in essence the way the network is laid out as it relates to the devices that are connected to it. If you could view all the devices connected to the network, the arrangement would suggest which type the network topology it falls within. The topologies can be described as either a physical or logical design in their defined layout. Network topologies are grouped in the following design categories, Mesh, Bus, Ring and Star Topologies.
A mesh topology comes in two varieties, Full mesh and Partial mesh. Full mesh consists of connectivity between every node on the network, meaning each has a direct path to the other. A partial mesh topology consists of the same type of ...view middle of the document...
This is because of the bus length and traffic that is broadcasted throughout it. Broadcast storms are common with this type of topology.
The Ring topology is defined exactly by its name, a ring. Within this topology every node has 2 neighbors, the one directly ahead and behind it on the ring. The data flow in this scenario is unidirectional around the ring. If a single node fails the ring fails, and the network as a whole is broken. Token ring is the most common form of this topology. Although you can still find this type of topology in some ISP’s through the use of FDDI and Sonet rings, Token ring is quickly being replaced by 802.3 Ethernet technologies.
The Star topology is designed in the shape of star. Every node in the network is connected through a centralized point. This makes the connectivity between the nodes indirect. While this type of network dedicates connectivity to each node, it also is vulnerable to complete network failure should the central point fail.
Many of today’s LAN and WAN networks share many of the features from the different topologies. Every Switch port is an arm of the star type topology. Every subnet could be defined as a bus topology, one large broadcast domain. Sonnet rings are commonly found among MANS and the Internet is one gigantic mesh topology. The important thing about topologies is to understand the theory. In order to properly design networks you must have a firm understanding of broadcasts, multicasts and routing.
The Institute of Electrical and Electronics Engineers (IEEE) specify 802.3 for the physical media characteristics of Ethernet. It defines the physical and data link layer for the media access control (MAC). It lays out the media types and their correspondent characteristics. The main advantage of Ethernet technology is its use as a communication media type between various types of communication protocols. Bandwidth speeds typically range from 10Mbs to 1Gbs. Ethernet is the most common communication method on today’s LANS.
Token Ring is the second most common protocol used in LANS today. While it will soon become obsolete,...