Chapter 13: Transmission Optimization Techniques

Overview

Until now, the primary focus of this book was on the creation and use of mathematical models to predict the performance of different types of local area networks (LANs) and internetworking devices. In this chapter we turn our attention to the use of several optimization techniques that, when incorporated into bridges and routers, will enhance the efficiency of inter- and intra-network transmission. In addition, we will examine the use of different types of network interface cards or adapters which, when used in a workstation, enhance its ability to transfer information onto and receive information from the network.

The techniques examined in this chapter include the use of filtering, precedence and express queuing, data compression, frame truncation , and the switched telephone network to supplement the use of leased lines during peak transmission periods. Readers should note that most remote bridge and router manufacturers provide one or more of the techniques described in this chapter. However, readers should also note that the efficiency of the implementation of each technique varies between vendors. In addition, most vendors only provide a small subset of the techniques covered in this chapter. Because the value of each technique is based on your specific networking requirements, you will have to compare the operational results of each technique against your specific communications environment to determine which techniques provide a higher level of networking capability and then use this chapter as a guide in your equipment selection process.

In examining network interface cards (NICs), our focus is on the different hardware design features and the effect of those features on the data transfer capability of the adapter. You can also use this information as a guide to facilitate your equipment selection process.