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Saturday, January 10, 2015

1000BASE-TX over CAT 6

1000BASE-TX over Category 6

TIA/EIA-854 : A Full Duplex Ethernet Physical Layer Specification for 1000Mb/s operating over Category 6 Balanced Twisted Pair Cabling (1000BASE-TX).
This writeups specifies a full duplex Ethernet physical layer interface for 1000Mb/s operation over a 100 meters of a Category 6 twisted pair cabling channel, referred to as 1000BASE-TX.

The purpose of this document, 1000BASE-TX, is to provide an Ethernet physical layer specification that is low complexity and can easily be implemented by many vendors. This will take advantage of the improved transmission parameters provided by Category 6 cabling.
It was believed by the members of this project that a much simpler solution for data rates of 1000Mb/s operating over a 100 meters of Category 6 UTP cabling would be a benefit to users who migrate to the higher data rates. It would eliminate the complicated requirements in the 1000BASE-T standard of canceling the effects of crosstalk and return loss, providing a solution that could operate at a much lower power level, the potential for multiple ports per chip, and could be implemented at a lower cost.  As it turned out, the ports became cheap very quickly and so no hardware vendor adopted this standard.

Key Technical Aspects

  • Performance: Cat 6 supports data transmission up to 10Gbps, making it excellent for 1000BASE-T (1Gbps) and backward compatible with 100BASE-TX.
  • Distance: You can achieve a full 100-meter (approx. 328 ft) run for 1000BASE-T.
  • Shielding (FTP/STP): Using Foiled Twisted Pair (FTP) or Shielded Twisted Pair (STP) Cat 6 ensures increased protection against Electromagnetic Interference (EMI), which is crucial for stable 10/100/1000Mbps speeds.
  • Connectors: Using high-quality Gold Plated RJ45 connectors ensures excellent conductivity and corrosion resistance.

Typical Use Cases

  • Ethernet Networking: Connecting routers, switches, and computers to achieve maximum Gigabit speeds.
  • HDMI over Cat6 Extenders: Using TX/RX (Transmitter/Receiver) kits to transmit 1080p or 4K video up to 30-60 meters
Tips for Installation
  • Cable Management: Keep the twist rate of the pairs intact close to the connector to maintain performance.
  • Termination: Utilize shielded RJ45 connectors if you are using shielded Cat 6 cables to ensure the shielding is effective.
  • Testing: Use a cable tester to ensure all 8 wires are connected properly, particularly for TX/RX setups

Ethernet Standards Table

IEEE Standard

Common Name

Maximum Data Rate

Maximum Cable Distance

IEEE 802.3ab

Gigabit Ethernet

1 Gbps

100 metres (328 ft)

IEEE 802.3bz

2.5GBASE-T / 5GBASE-T

2.5 Gbps / 5 Gbps

100 metres (328 ft)

IEEE 802.3an

10GBASE-T

10 Gbps

55 metres (180 ft)

IEEE 802.3u

Fast Ethernet

100 Mbps

100 metres (328 ft)

IEEE Power over Ethernet (PoE) on Cat6

Cat6 conductors are highly optimized for delivering concurrent remote power and data. The solid copper construction helps mitigate thermal buildup during high-wattage transfers:

  • IEEE 802.3af (PoE): Delivers up to 15.4W of DC power to basic network hardware like standard IP cameras.
  • IEEE 802.3at (PoE+): Supplies up to 30W of DC power for dual-band wireless access points and PTZ cameras.
  • IEEE 802.3bt (4PPoE / PoE++): Utilizes all four twisted pairs to deliver 60W (Type 3) to 90W/100W (Type 4) of power, designed for high-performance enterprise equipment.

Key Implementation Rules
  • The 100-Metre Channel Rule: For 1G, 2.5G, and 5G speeds, the IEEE channel model limits your total length to 90 metres of permanent solid horizontal link and 10 metres of combined stranded patch cables.
  • The 10Gbps Constraint: Moving to 10GBASE-T reduces the distance to 55 metres due to high-frequency alien crosstalk. Upgrading to a specialized StarTech Cat6a Shielded Patch Cable or full Cat6A horizontal runs is required to maintain 10Gbps across the full 100-metre distance.
  • Shielding Requirements: For dense commercial or high EMI environments, use shielded options that meet the ANSI/TIA-568.2-D cabling standards alongside IEEE-compliant active switches to guarantee full signal integrity.



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