Which lan topology requires the most cabling?
What is a Topology?The physical topology of a network refers to the configuration of cables, computers, and other peripherals. Physical topology should not be confused with logical topology which is the method used to pass information between workstations. Logical topology was discussed in the Protocol chapter. Show
Main Types of Physical TopologiesThe following sections discuss the physical topologies used in networks and other related topics.
Linear BusA linear bus topology consists of a main run of cable with a terminator at each end (See fig. 1). All nodes (file server, workstations, and peripherals) are connected to the linear cable. Fig. 1. Linear Bus topology Advantages of a Linear Bus Topology
Disadvantages of a Linear Bus Topology
StarA star topology is designed with each node (file server, workstations, and peripherals) connected directly to a central network hub, switch, or concentrator (See fig. 2). Data on a star network passes through the hub, switch, or concentrator before continuing to its destination. The hub, switch, or concentrator manages and controls all functions of the network. It also acts as a repeater for the data flow. This configuration is common with twisted pair cable; however, it can also be used with coaxial cable or fiber optic cable. Fig. 2. Star topology Advantages of a Star Topology
Disadvantages of a Star Topology
Tree or Expanded StarA tree topology combines characteristics of linear bus and star topologies. It consists of groups of star-configured workstations connected to a linear bus backbone cable (See fig. 3). Tree topologies allow for the expansion of an existing network, and enable schools to configure a network to meet their needs. Fig. 3. Tree topology Advantages of a Tree Topology
Disadvantages of a Tree Topology
5-4-3 RuleA consideration in setting up a tree topology using Ethernet protocol is the 5-4-3 rule. One aspect of the Ethernet protocol requires that a signal sent out on the network cable reach every part of the network within a specified length of time. Each concentrator or repeater that a signal goes through adds a small amount of time. This leads to the rule that between any two nodes on the network there can only be a maximum of 5 segments, connected through 4 repeaters/concentrators. In addition, only 3 of the segments may be populated (trunk) segments if they are made of coaxial cable. A populated segment is one that has one or more nodes attached to it . In Figure 4, the 5-4-3 rule is adhered to. The furthest two nodes on the network have 4 segments and 3 repeaters/concentrators between them. NOTE: This rule does not apply to other network protocols or Ethernet networks where all fiber optic cabling or a combination of a fiber backbone with UTP cabling is used. If there is a combination of fiber optic backbone and UTP cabling, the rule would translate to a 7-6-5 rule.The speed of networking switches is vastly improved over older technologies, and while every effort should be made to limit network segment traversal, efficient switching can allow much larger numbers of segments to be traversed with little or no impact to the network. Considerations When Choosing a Topology
Summary Chart
Which of the following network topologies requires more cabling?Disadvantages of a Star Topology
Requires more cable length than a linear topology. If the hub, switch, or concentrator fails, nodes attached are disabled.
Which type of topology has the greatest number of physical connections?only a mesh physical topology has point-to-point connections to every device, so it has more connections and is not a popular LAN technology.
What is the most popular topology that is used on modern LANs?Star topology is the most common. This is often a switch, with multiple computers connected through that switch.
Which of the following topologies has the highest redundancy level?Mesh network topology is most fault tolerant and has most redundancy.. In a mesh topology, all devices are connected directly to every other device on the network.. |