Hardware Reference
In-Depth Information
Figure 17.19. A typical wireless network with multiple access points.
As you can see, as users with wireless NICs move from one office to another, the roaming feature of
the NIC automatically switches from one access point to another, permitting seamless network
connectivity without wires or logging off the network and reconnecting.
Users per Access Point
The number of users per access point varies with the product; Wi-Fi access points are available in
capacities supporting anywhere from 15 to as many as 254 users. You should contact the vendor of
your preferred Wi-Fi access point device for details.
Although wired Ethernet networks are still the least expensive networks to build if you can do your
own wiring, Wi-Fi networking is now cost-competitive with wired Ethernet networks when the cost
of a professional wiring job is figured into the overall expense.
Because Wi-Fi is a true standard, you can mix and match access point and wireless NIC hardware to
meet your desired price, performance, and feature requirements for your wireless network, just as you
can for conventional Ethernet networks, provided you match up frequency bands or use dual-band
hardware.
Network Protocols
A few years ago, the second-most important choice you had to make when you created a network was
which network protocol to use because the network protocol affects which types of computers your
network can connect. Today, the choice has largely been made for you: TCP/IP has replaced other
network protocols such as IPX/SPX (used in older versions of Novell NetWare) and NetBEUI (used
in older Windows and DOS-based peer-to-peer networks and with Direct Cable Connection) because
it can be used both for Internet and LAN connectivity. TCP/IP is a universal protocol that virtually all
OSs can use.
Although data-link protocols such as Ethernet require specific types of hardware, network protocols
are software and can be installed to or removed from any computer on the network at any time, as
necessary.
Table 17.9
summarizes the differences between these protocols.
Table 17.9. Overview of Network Protocols and Suites
All the computers on any given network must use the same network protocol or protocol suite to
communicate with each other.
IP and TCP/IP
IP stands for Internet Protocol; it is the network layer of the collection of protocols (or protocol suite)
developed for use on the Internet and commonly known as TCP/IP.
Later, the TCP/IP protocols were adopted by the UNIX OSs. They have now become the most
