Wiring a Twisted Pair Ethernet Network
Laboratory Exercise # 1
OBJECTIVES AND MATERIALS
Objectives:
Following this laboratory session, students should be capable of:
1. Distinguishing between a straight-through cable, crossover cable, and rollover
cable.
2. Constructing straight-through, crossover, and rollover cables, and
3. Assessing the functionality of various UTP wiring configurations.
Materials:
PART
QUANTITY DESCRIPTION
NUMBER
6m - Category 5 UTP cable
1 - Crimping Tool / Wire stripper
9 - RJ-45 Connector
1 - UTP Cable Tester
PROCEDURES
Background
The EIA/TIA wiring standards, first published in 1991, have evolved over the years.
The current EIA/TIA-568 standard, especially the 568B version, specifies cable
dimensions and installation procedures. This standard is followed by Category 5, the
highest-quality Unshielded Twisted Pair (UTP) cable. Category 5 is tested at 100 MHz and
enables high-speed protocols like as 100 Mbps Fast Ethernet and FDDI by using 22 or 24
AWG unshielded twisted pair cable with a 100-ohm impedance.
, The IEEE established three new physical layers for 100 Mbps Fast Ethernet, with
100Base-TX being the most extensively used. Strict adherence to RJ-45 cable installation
is critical, since non-compliance might result in high-speed data transmission difficulties,
notably Near-End Crosstalk (NEXT). Signal spillover occurs as a result of NEXT, the
unintended coupling of signals between twisted pairs, resulting in distorted data or
connection failure. Even with four twisted pairs on a Cat 5 cable, compliance with the
EIA/TIA standard needs correct RJ-45 connection for best performance.
UTP (Category 5) LAN cables are widely used and consist of four twisted pairs
(eight wires). The insertion of RJ45 connections at both ends converts it into a standard
LAN cable for networking.
A
B
Figure 1 – (a) Internal Structure of UTP (Category 5), (b) UTP Cable with RJ-45
Connector
A. Straight Through (ST) - Used for connecting different devices (workstations to hubs,
switches to routers, hubs to hubs, and so on). On both ends, the cables are connected
using the same wiring layout.
Figure 2 - T-568A Straight-Through Ethernet Cable