Ethernet Cables – Cat5 and Cat5e

Where do the terms Cat5 and Cat5e come from?

TIA Telecommunications Industry Association, TIA defined standard TIA-568-B which defines the cables and structured or modular cabling systems and termination standards for building and telecom cabling systems.

Cat5 and Cat5e Cable’s What is the difference?

  • Very simply put: The 5e cable is tested to a higher standard. A manufacturer may produce a single cable and only test some of it to the 5e standard. The physical characteristics of the cable are no different but the Cat5e’s higher specification makes it suitable for Gigabit Ethernet.
  • Whilst we are on the subject what about Cat6 ? Bandwidth is 2.5 greater at 250MhZ and that’s probably the limit with RJ45 connectors. You might be future proofing using this cable but you could also be wasting money. Also remember that Cat6 is a high tech cable and requires connectors and patch cables assembled to meet the standard.
  Category 5 Category 5e
Frequency 100 MHz 100 MHz
Attenuation (Min. at 100 MHz) 22 dB 22 dB
Characteristic Impedance 100 ohms ± 15% 100 ohms ± 15%
NEXT (Min. at 100 MHz) 32.3 dB 35.3 dB
PS-NEXT (Min. at 100 MHz) no specification 32.3 dB
ELFEXT (Min. at 100 MHz) no specification 23.8 dB
PS-ELFEXT (Min. at 100 MHz) no specification 20.8 dB
Return Loss (Min. at 100 MHz) 16.0 dB 20.1 dB
Delay Skew (Max. per 100 m) no specification 45 ns


Ethernet Cable Color Coding

There are two color coding standards. The color coding standard does not affect whether the cable is a cross-over or straight through patch cable. Color does not affect performance or use of the cable.

Standard 568A   Standard 568B
This is the most commonly used for patch cables.
1 White-Green   1 White-Orange
2 Green   2 Orange
3 White-Orange   3 White-Green
4 Blue   4 Blue
5 White-Blue   5 White-Blue
6 Orange   6 Green
7 White-Brown   7 White-Brown
8 Brown   8 Brown