Practical TCP/IP and Ethernet Networking- P7: One of the great protocols that has been inherited from the Internet is TCP/IP and this is being used as the open standard today for all network and communications systems. The reasons for this popularity are not hard to find. | 42 Practical TCP IP and Ethernet Networking In LANs polling provides a deterministic media access method in which the server polls each node in succession to determine whether that node wants to access the network. In some systems the polling is done by means of software messages being passed to and fro which could slow down the process. In order to overcome this problem systems such as 100VG Any LAN employ a hardware-polling message which uses voltage levels to determine whether a node wants to be serviced. 3 Ethernet networks Objectives When you have completed study of this chapter you should be able to Describe the major hardware components of an IEEE CSMA CD network Explain the method of connection of 10Base5 10Base2 and 10BaseT networks Explain the operation of the CSMA CD protocol List the fields in the Ethernet data frames Describe the causes of Ethernet collisions and how to reduce them Demonstrate how to apply the Ethernet design rules IEEE CSMA CD Ethernet The Ethernet network concept was developed by Xerox Corporation at its Palo Alto Research Center PARC in the mid-seventies. It was based on the work done by researchers at the University of Hawaii where there were campus sites on the various islands. Its ALOHA network was set up using radio broadcasts to connect the various sites. This was colloquially known as their Ethernet since it used the ether as the transmission medium and created a network net between the sites. The philosophy was quite straightforward. Any station that wanted to broadcast to another station would do so immediately. The receiving stations then had a responsibility to acknowledge the message thus advising the original transmitting station of a successful reception of the original message. This primitive system did not rely on any detection of collisions two radio stations transmitting at the same time but rather waited for an acknowledgment back within a predefined time. The initial system installed by Xerox was .
