Hardware Reference
In-Depth Information
As you can see, using a switch instead of a hub greatly increases the effective speed of
a network, even if all other components remain the same. Originally switches were very
expensive,somanynetworkswerebuiltusinghubsinstead.Butoncethepriceofaswitch
fell to equal or below the cost of a hub, hubs became obsolete.
Note
Both wired and wireless routers (a
router
connects a local area network to a device that
provides Internet access, such as a cable or DSL modem) typically incorporate full-duplex
10/100 (Fast Ethernet) or 10/100/1000 (Gigabit Ethernet) switches.
For more information about routers,
see
“
Routers for Internet Sharing
,
”
p.
787
(
Chapter 16
,
“
Internet Connectivity
”).
At this point the lower cost and significantly higher performance of switches mean that
you should consider replacing any hubs that might still be in use.
Additional Switch Features You Might Need
Most switches have the following standard or optional features:
•
Multispeed capability
—Switches support multiple speeds. This means you can mix
Gigabit Ethernet (1000BASE-TX), Fast Ethernet (100BASE-TX) and 10BASE-T cli-
ents on the same network, and each will run at the maximum possible speed. These
days I recommend buying only Gigabit switches, since most network adapters now
support Gigabit speeds.
•
“Extra”portsbeyondyourcurrentrequirements
—Ifyouareconnectingfourcom-
puters into a small network, you may only need a four-port switch, which is the smal-
lest generally available. But if you buy a switch with only four ports and want to add
another client PC to the network, you must add a second switch or replace the switch
with a larger one with more ports.
Instead, plan for the future by buying a switch that can handle your projected network
growth over the next year. If you plan to connect more than four workstations, buy
at least an eight-port switch. (The cost per connection drops as you buy hubs and
switches with more connections.) Even though you can easily interconnect additional
switches, it is normally more economical to use as few switches as possible.
