UTP Connecting Hardware: Insertion Loss (Attenuation) and NEXT
This guide shows Insertion Loss (Attenuation) and Near-End CrossTalk (NEXT) for UTP (Unshielded Twisted Pair) Cat 3, Cat 4, Cat 5e, and Cat 6
network cables measured in decibels.
Frequency
(MHz) |
Cat 3 |
Cat 4 |
Cat 5e |
Cat 6 |
Attn
(dB) |
NEXT
(dB) |
Attn
(dB) |
NEXT
(dB) |
Attn
(dB) |
NEXT
(dB) |
Attn
(dB) |
NEXT
(dB) |
| 1.00 |
0.1 |
58.0 |
0.1 |
65 |
0.1 |
65.0 |
0.10 |
75.0 |
| 4.00 |
0.2 |
46.0 |
0.1 |
58 |
0.1 |
65.0 |
0.10 |
75.0 |
| 8.00 |
0.3 |
39.9 |
0.1 |
52 |
0.1 |
64.9 |
0.10 |
75.0 |
| 10.00 |
0.3 |
38.0 |
0.1 |
50 |
0.1 |
63.0 |
0.10 |
74.0 |
| 16.00 |
0.4 |
33.9 |
0.2 |
46 |
0.2 |
58.9 |
0.10 |
69.9 |
| 20.00 |
--- |
--- |
0.2 |
44 |
0.2 |
57.0 |
0.10 |
68.0 |
| 25.00 |
--- |
--- |
--- |
--- |
0.2 |
55.0 |
0.10 |
66.0 |
| 31.25 |
--- |
--- |
--- |
--- |
0.2 |
53.1 |
0.11 |
64.1 |
| 62.50 |
--- |
--- |
--- |
--- |
0.3 |
47.1 |
0.16 |
58.1 |
| 100.00 |
--- |
--- |
--- |
--- |
0.4 |
43.0 |
0.20 |
54.0 |
Frequency
(MHz) |
Cat 3 |
Cat 4 |
Attn
(dB) |
NEXT
(dB) |
Attn
(dB) |
NEXT
(dB) |
| 1.00 |
0.1 |
58.0 |
0.1 |
65 |
| 4.00 |
0.2 |
46.0 |
0.1 |
58 |
| 8.00 |
0.3 |
39.9 |
0.1 |
52 |
| 10.00 |
0.3 |
38.0 |
0.1 |
50 |
| 16.00 |
0.4 |
33.9 |
0.2 |
46 |
| 20.00 |
--- |
--- |
0.2 |
44 |
| 25.00 |
--- |
--- |
--- |
--- |
| 31.25 |
--- |
--- |
--- |
--- |
| 62.50 |
--- |
--- |
--- |
--- |
| 100.00 |
--- |
--- |
--- |
--- |
Frequency
(MHz) |
Cat 5e |
Cat 6 |
Attn
(dB) |
NEXT
(dB) |
Attn
(dB) |
NEXT
(dB) |
| 1.00 |
0.1 |
65.0 |
0.10 |
75.0 |
| 4.00 |
0.1 |
65.0 |
0.10 |
75.0 |
| 8.00 |
0.1 |
64.9 |
0.10 |
75.0 |
| 10.00 |
0.1 |
63.0 |
0.10 |
74.0 |
| 16.00 |
0.2 |
58.9 |
0.10 |
69.9 |
| 20.00 |
0.2 |
57.0 |
0.10 |
68.0 |
| 25.00 |
0.2 |
55.0 |
0.10 |
66.0 |
| 31.25 |
0.2 |
53.1 |
0.11 |
64.1 |
| 62.50 |
0.3 |
47.1 |
0.16 |
58.1 |
| 100.00 |
0.4 |
43.0 |
0.20 |
54.0 |
What is Insertion Loss?
Insertion Loss, also called Attenuation, represents the energy lost in the signal as the signal travels through the network cable. Insertion loss is measured in decibels (dB).
What is NEXT?
NEXT is an abbreviation for Near End Crosstalk.
Pair-to-Pair Near End Crosstalk can occur in adjacent twisted pair wires when data on one twisted pair is electromagnetically coupled back to an adjacent twisted pair causing interference.
NEXT measures the amount of signal electromagnetically transferred between adjacent twisted pairs in a network cable at the near (source) end of the cable. Near End Cross Talk (NEXT) varies by category
cable type and by frequency. Ensuring that each twisted pair is tightly twisted can reduce NEXT and allow the network cable to transmit at higher data rates.
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Warning: When using this information to perform electrical work, call a licensed electrician and consult the NEC® for safety.
All licensed electricians have passed examinations covering the National Electric Code®, know state and
local building codes, and may carry insurance to cover damages.