Ethernet Cables
Comparison between CAT5, CAT5e, CAT6, CAT7 Cables

                            

In the context of the 100-ohm UTP (Unshielded Twisted Pair) type of cable used for Ethernet wiring the only categories of interest are Cat3, Cat4, Cat5, Cat5e, Cat6, and Cat7. CATx is an abbreviation for the category number that defines the performance of building telecommunications cabling as outlined by the Electronic Industries Association (EIA) standards. Some specifications for these categories are shown further down.

Up until the late 1980s thick or thin coaxial cable was typically used for 10-Mbps Ethernet networks, but around that time, UTP cabling became more commonly used because it was easier to install and less expensive. UTP CAT3 and CAT4 were used for a quite limited time since the emergence of 100Base-TX networks meant a quick shift to CAT5. By the year 2000, moves to gigabit (1000Base-TX) Ethernet LANs created a need for another specification, CAT5e. CAT5e is now being superseded by CAT6 cable and there is a developing standard for CAT7.

Specifications for Cat3, Cat4, Cat5, Cat5e, Cat6, Cat6A and Cat7 Cables

Category

Type

Spectral B/W

Length

LAN Applications

Notes

Cat3

UTP

16 MHz

100m

10Base-T, 4Mbps

Now mainly for telephone cables

Cat4

UTP

20 MHz

100m

16Mbps

Rarely seen

Cat5

UTP

100MHz

100m

100Base-Tx,ATM,CDDI

Common for current LANs

Cat5e

UTP

100MHz

100m

1000Base-T

Common for current LANs

Cat6

UTP

250MHz

100m

Exceeds 1000Base-T

  

Cat6A

both

500MHz

100m

10 GigE

  

Cat7

ScTP

600MHz

100m

    
TABLE 4: Industry Standards Performance Comparison at 100 MHz for Channels
  Category 5e Category 6 Category 6A Class F Class FA
Frequency Range (MHz) 1 - 100 1 - 250 1 - 500 1 - 600 1 - 1,000
Insertion Loss (dB) 24.0 21.3/21.7 20.9 20.8 20.3
NEXT Loss (dB) 30.1 39.9 39.9 62.9 65.0
PSNEXT Loss (dB) 27.1 37.1 37.1 59.9 62.0
ACR (dB) 6.1 18.6 18.6 42.1 46.1
PSACR (dB) 3.1 15.8 15.8 39.1 41.7
ACRF1 (dB) 17.4 23.3 23.3/25.5 44.4 47.4
PSACRF2 (dB) 14.4 20.3 20.3/22.5 41.4 44.4
Return Loss (dB) 10.0 12.0 12.0 12.0 12.0
PSANEXT Loss (dB) n/s n/s 60.0 n/s 67.0
PSAACRF (dB) n/s n/s 37.0 n/s 52.0
TCL (dB) n/s n/s 20.3 20.3 20.3
ELTCTL3 (dB) n/s n/s 0.5/0 3) 0 0
Propagation Delay (ns) 548 548 548 548 548
Delay Skew (ns) 50 50 50 30 30
  1. Specified as ELFEXT for category 5e/class D and category 6/class E.
  2. Specified as PSELFEXT for category 5e/class D and category 6/class E.
  3. ELTCTL is specified at 30 MHz.
  4. Table 4 is from http://www.siemon.com/us/white_papers/07-03-01-demystifying.asp