Appendix D Commonly Asked Questions
15
KND2410TX User’s Guide - Rev. A01 Kingston Technology Company
Appendix D Commonly Asked Questions
Class
I
vs. Class
II
100BASE-TX Fast Ethernet Repeaters
There are currently two classes of Fast Ethernet repeaters, defined as Class
I
and Class
II
.
Class
I
:
in a maximum length segment topology, only
one
Class
I
repeater may exist between any two nodes within a single
collision domain.
Class
II
:
in a maximum length segment topology,
two
Class
II
repeaters may exist between any two nodes within a single collision
domain.
Will 100BASE-TX run on Category 3 cable?
No! Category 3 (CAT 3) cabling even in short lengths generates too much near
end crosstalk for 100BASE-TX networks. The IEEE 802.3u 100BASE-TX Fast
Ethernet standard requires Category 5 100
Ω
UTP or 100
Ω
STP which
complies with ISO/IEC 11801:1995.
What is Category 5?
Category 5 (CAT 5) is a further extension of the EIA/TIA-568 cabling system
to 100 MHz. Category 5 components (i.e., UTP trunk and patch cables,
modular plug, and patch panel, etc.) are defined by EIA/TIA-568, but with the
characterizations extended to 100 MHz by TSB-36 and TSB-40. The cable
grades are categorized as follows:
•
Category 3:
up to 16 MHz
•
Category 4:
up to 20 MHz.
•
Category 5:
up to 100 MHz.
