Hardware Reference
In-Depth Information
Note
Most standard cables have both ends wired using the EIA 568B standard, however it is also
possible to wire them with both ends using the EIA 568A standard. As long as both ends
are wired the same in a straight-through configuration, the cable will work. Crossover cables
should have one end in an EIA 568B configuration, while the other end is in an EIA 568A
configuration, thus crossing pairs 2 and 3. It should be noted that other wiring schemes exist
for connecting UTP cables with 8P8C (RJ-45) connectors. The ones listed in this chapter are
the most common.
Most newer switches are designed so as to automatically detect whether a crossover
connection is required and configure the connection appropriately. This feature is called
Auto-MDIX (automatic medium-dependent interface crossover) and essentially negates
the need for having dedicated “uplink” ports or using crossover cables when connecting
devices together.
Constructing the Cable
Making your own network cables requires a few tools that aren't found in a typical tool-
box. Those items that you might not already have you can typically purchase for a single
price from many network-products vendors. You need the following tools and supplies to
build your own Ethernet cables:
• UTP cable (Category 5 or better)
• 8P8C (RJ-45) connectors
• Wire stripper
• 8P8C (RJ-45) crimping tool
