Network Infrastructure and Architecture: Designing High-Availability Networks

12

NETWORK ELEMENTS

12.1 Introduction

12.2 Networking Functions

12.2.1 Information Transfer and Regeneration Function

12.2.2 Multiplexing Function

12.2.3 Grooming Function

12.2.4 Switching Function

12.2.5 Routing Function

12.3 Networking Equipment

12.3.1 Regeneration Equipment

12.3.2 Grooming Equipment

12.3.3 Multiplexing Equipment

12.3.4 Switching Equipment

12.3.5 Routing Equipment

12.4 Summary

Key Points

References

12.1 INTRODUCTION

Whether they are corporate intranets, wireline carrier networks, or wireless networks, networks are comprised basically of nodes and transmission channels. Nodes, also known as network elements (NEs), support a variety of communication functions. Several dozen different NEs exist for the aforementioned networks. Many of these NEs reside at a particular layer of the Open Systems Interconnection Reference Model (OSIRM); others support several layers of the protocol model. (Generally, it is more cost-effective to have an NE cover multiple layers than discrete devices; this way, there is no need for multiple chassis, multiple power supplies, multiple racks with interconnecting cables, multiple network monitoring systems, and so on.) Regardless of the functional bundling, NEs are critical to proper functioning of any network.

In this chapter we look at some of the basic NEs that are commonly used to construct communication networks. Specifically, the purpose of this chapter is to review basic networking functions and contrast switching to grooming and ...