SkipCaptcha
292
edits
Changes
Jump to navigation
Jump to search
Line 2:
Line 2: + + − + + + Line 12:
Line 16: − + − Wireless internet ([[WiFi]], [[WiMax]], etc.) must utilize this network architecture, with the wireless access point being the central node. A collision avoidance system is used to ensure that only one client is transmitting at a time. This kind of topology also has several other uses. For example, a star network may be used to isolate untrusted clients from each other using separate lines directly from each one to the router, where port security prevents communication between them.+
Slight reorganization and expansion.
==Classifications==
==Classifications==
Buses are classified by the way the links between various nodes are shared.
===Bus===
===Bus===
A bus topology has all nodes connected to the same link. The advantage of this approach is in its simplicity and cost. Contention on the link requires either control signals to arbitrate between nodes wishing to use the link at the same time, or a means of detecting (and correcting) the situation when multiple nodes attempt to transmit data on the link simultaneously (called a ''collision''). Ethernet networks use a bus topology that detects collisions and retransmits data afterwards.
A bus topology has all nodes connected to the same link. The advantage of this approach is in its simplicity and cost. Contention on the link requires either control signals to arbitrate between nodes wishing to use the link at the same time, or a means of detecting (and correcting) the situation when multiple nodes attempt to transmit data on the link simultaneously (called a ''collision''). The more nodes there are on the link, the more contention there is for access to it, and the slower the network seems to each individual node. For this reason, bus topologies are often broken down into a hierarchical mixed topology, with subsections of the network (or '''subnets''') sharing a bus, but each subnet is connected to other subnets through a router/switch.<br>
In a peer-to-peer (P2P) arrangement, each node on the bus (which may be a physical wire or a given radio frequency), can connect directly to any other node on the bus. In a "master/slave" (M/S) configuration, one node (the master) is responsible for coordinating which nodes are allowed to communicate, or may be responsible for taking the data from one node and then retransmitting it to the destination node. This resembles a star topology, except that all nodes use the same bus, although only one can be transmitting at a time. In a true star topology, the nodes can only see the central node. In a bus topology, all nodes can see the transmissions of other nodes, even if they ignore them.<br>
Ethernet and Wireless internet ([[WiFi]], [[WiMax]], etc.) use a bus topology that detects collisions and retransmits data afterwards. Before SATA hard disks, IDE cables allowed up to two hard disk drives (or floppy disk drives) per physical cable using M/S configuration. In the modern day IDE is usually used only for DVD drives.
===Ring===
===Ring===
===Star===
===Star===
A star topology has a central node which is responsible for routing all network traffic between the rest of the nodes. The rest of the nodes connect only to the central node. The advantage is that there is no contention on the links, but the central node becomes a bottleneck. The central node has a limited throughput, so if the demand is too high, the central node will no longer be able to manage the volume of traffic.<br />
A star topology has a central node which is responsible for routing all network traffic between the rest of the nodes. The rest of the nodes connect only to the central node. The advantage is that there is no contention on the links, but the central node becomes a bottleneck. The central node has a limited throughput, so if the demand is too high, the central node will no longer be able to manage the volume of traffic. Network switches act as the central node for a star topology. Network routers may act as the central node in a wired star topology while also acting as the master node on a bus topology for WiFi connections.<br />
This kind of topology also has several uses. For example, a star network may be used to isolate untrusted clients from each other using separate lines directly from each one to the router, where port security prevents communication between them.
===Mesh===
===Mesh===