|
Networking media is literally and
physically the backbone of a network. Inferior quality of network
cabling results in network failures and unreliable performance.
Copper, optical fiber, and wireless networking media all require
testing to determine the quality. These tests involve certain
electrical and mathematical concepts and terms, such as signal,
wave, frequency, and noise. Understanding this vocabulary is
helpful when learning about networking, cabling, and cable
testing.
The goal of the first lesson in this module is to
provide some basic definitions so that the cable testing concepts
presented in the second lesson will be better understood.
The second lesson of this module describes the issues
relating to the testing of media used for physical layer
connectivity in local-area networks (LANs). In order for the LAN
to function properly, the physical layer medium must meet the
industry standard specifications.
Attenuation (signal deterioration)
and noise (signal interference) cause problems in networks because
the data is not recognizable when it is received. Proper
attachment of cable connectors and proper cable installation are
important. If standards are followed in these areas, attenuation
and noise levels are minimized.
After cable has been installed, it
must be tested with quality cable testers to verify that the
specifications of the TIA/EIA standards are met. This module also
describes the various important tests that are performed.
Students completing this module should be able to:
- Differentiate between sine waves
and square waves.
- Define and calculate exponents
and logarithms.
- Define and calculate decibels.
- Define basic terminology related
to time, frequency, and noise.
- Differentiate between digital
bandwidth and analog bandwidth.
- Compare and contrast noise
levels on various types of cabling.
- Define and describe the affects
of attenuation and impedance mismatch.
- Define crosstalk, near-end
crosstalk, far-end crosstalk, and power sum near-end crosstalk.
- Describe how crosstalk and
twisted pairs help reduce noise.
- Describe the ten copper cable
tests defined in TIA/EIA-568-B.
- Describe the difference between
Category 5 and Category 6 cable.
|
