Changes

===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'').  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>

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.

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.

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.

 

Ethernet, Cable internet, 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.

 

There are security implications for this topology.  Since all nodes on the bus can see the transmissions of all other nodes on the bus, each connection between two nodes must be protected by a security protocol.  The most common form used on the internet is SSH (Secure Sockets), which encrypts the data in a way that only the two nodes can decrypt.  Without a security protocol, any other node on the bus could observe and record any data being transferred.  Software that watches for unencrypted data is called a '''sniffer''' and can be used to steal confidential information including, but not limited to, social security numbers, phone numbers, and credit card numbers.  Any use of the internet in which confidential information is transmitted should be protected by the use of SSH, or another secure protocol.  The HTTPS:// web protocol uses SSH, whereas HTTP:// is inherently insecure.

===Ring===

===Ring===