Specifications

Chapter 1 Understanding Networking and IP Addressing
Introduction to Networking
Niagara Release 2.3
Niagara Networking & Connectivity Guide Revised: May 22, 2002
1–3
Types of Networks
The evolution of PC networking technology started with specialized disk servers that
ran special operating systems (OSs) supporting simultaneous file access from a group
of clients. The biggest drawback to this design is that it requires a powerful computer
dedicated to running the network operating system. Over time, this approach has
evolved into one where each PC on the network can be both client and server: Today,
individual PCs can be configured so users on other PCs can access specific areas on
their disk and use devices to which they are connected. Because any client can be a
file server and any server can be a client, the systems are considered to have peer
status.
Server-based
Networks
In a server-based network, the PCs that attempt to access the network are monitored
by a central access control manager. Typically, a PC is given all information about
the network users, which are each assigned user permissions, passwords, and access
rights to the various resources on the network according to their needs. Users can be
grouped (in user groups) to more easily manage their access privileges. The PC that
has this management function is referred to as the logon server or domain controller,
and it is possible for multiple PCs to share these server responsibilities.
Peer-to-peer
Networks
Peer-to-peer networks involve PCs that manage their own network connection on the
common media. In other words, logging onto the network and the resources that can
be accessed on the network is a function that is managed by the PC that is connecting.
All PCs are equal in priority—no one PC can prevent another PC from connecting to
the network. In a peer-to-peer network, there is little or no network security offered
—when a user logs onto the PC, they are automatically logged onto the network.
Specialized
Servers
Often, specialized servers are used to perform server level functions on a network
other than access control. These might include print servers, database servers, and
application servers. In the Microsoft world, these are referred to as member servers.
Normally, these PCs are not used as individual workstations that double as an
application server—they typically sit off on the sidelines managing their resources,
providing group connectivity.
Network Design
Networked PCs need some form of communications system that provides a fast and
reliable transport system for messaging. This section discusses the hardware, cabling,
and architecture used to support network communications.
Standard
Topologies
The physical layout or description of a network is called topology. The three most
common topologies are: bus, star, and ring. Combinations of these can also be used
to create hybrid topologies.