The FTCSMA/CD network
This paper presents a new network model, FTCSMA/CD to provide fault-tolerant capability on IEEE 802.3 (CSMA/CD). This model inserts a sublayer between the LLC (logical link control) sublayer and MAC (medium access control) sublayer, in order to provide the fault tolerance function. That insertion sublayer is called ILM (Interface between LLC and MAC). The new network model adopts two channels as the communication path, but only one channel is permitted to work at a time. Though the network bandwidth of this network model is not expanded, the network model still reached the goal of network fault tolerance. Further, the network model design is based on compatibility with the existent ethernet, so that the original software in the existent network could be used in the fault-tolerant model.