In computer networking, topology refers to the layout of connected devices.
This lesson introduces the standard topologies of networking.
Network topologies are categorized into the following basic types:
* bus
* ring
* star
* tree
* mesh
Bus Topology
Bus networks (not to be confused with the system bus of a computer) use a common backbone to connect all devices.
A single cable, the backbone functions as a shared communication medium that devices attach or tap into with an interface connector.
A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message.
Ring Topology
In a ring network, every device has exactly two neighbors for communication purposes.
All messages travel through a ring in the same direction (either "clockwise" or "counterclockwise").
A failure in any cable or device breaks the loop and can take down the entire network.
Star Topology
Many home networks use the star topology. A star network features a central connection point called a "hub" that may be a hub, switch or router.
Devices typically connect to the hub with Unshielded Twisted Pair (UTP) Ethernet.
Tree Topology
Tree topologies integrate multiple star topologies together onto a bus.
In its simplest form, only hub devices connect directly to the tree bus, and each hub functions as the "root" of a tree of devices.
This bus/star hybrid approach supports future expandability of the network much better than a bus (limited in the number of devices due to the broadcast traffic it generates) or a star (limited by the number of hub connection points) alone.
Mesh Topology
Mesh topologies involve the concept of routes. Unlike each of the previous topologies, messages sent on a mesh network can take any of several possible paths from ist, messages can only travel in one direction.)
Some WANs, most notably the Internet, employ mesh routing.
No comments:
Post a Comment