Kingston Technology KND810TX User Manual

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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.