In a star topology, each station connects directly to a central network hub. A network relies on a protocol, which is a set of rules that govern data communications. Without this agreement between the communicating devices, no communication will take place. This set of rules include specifications that regulate the characteristics of a network, such as the access method, allowed physical topologies, types of cabling, and speed of data transfer. The Ethernet, Fast-Ethernet, Local Talk, Token Ring, and Asynchronous Transfer Mode (ATM) are all protocols that use a star topology.
The most widely used protocol; the Ethernet utilises the access method of Carrier Sense Multiple Access/Collision Detection, or CSMA/CD. Since the creation of the traditional Ethernet in 1979 at Xerox's Palo Alto Research Center, four generations have become a reality. The original Ethernet speed is at 10 megabytes per second (MBps) using the twisted pair cable, the 10Base-T, coaxial cable the 10Base5, thick Ethernet or thicknet, and fibre optic cable, the 10Base-F.
Fast Ethernet offers an increase in the transmission speed, a new standard that supports 100 Mbps. Fast Ethernet also requires the use of more expensive network hubs and network interface cables -- category 5 twisted pair or fibre optic.
Developed by Apple Computer, Inc., the Local Talk is the network protocol used for Macintosh computers. The Local Talk uses the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) method whereas a computer signals its intent to transmit prior to the actual transmission. The twisted-pair cable uses a star topology. The speed transmission of Local Talk is .23 Mbps.
Asynchronous Transfer Mode (ATM) is a network protocol that transmits data at a speed of 155 to 2,499 Mbps. The ATM protocol works with a star topology, which uses fibre optic or twisted pair cabling, and transmits data in small packets of a fixed size. ATM supports the transmission of various media, including CD-quality audio and imaging.
- "Introduction to Networking"; by Behrouz A. Forouzan; 2007