Twisted Pair Cables

• Two Copper conductors form a path for an electrical signal

  • Each wire carries an equal but opposite signal

• Twisted to reduced crosstalk

• Covered in plastic insulation, and an outer sheath

• Most cables contain four twisted pairs.

  • Each pair is twisted a different amount, to reduce crosstalk

• Cables have good flexibility

• Cheap cables

• Easy to install

• Supports newer protocols

• Susceptible to Interference, EMI, and Eavesdropping. 

  • The sheath around the cable is pretty thin

Plenum Space: Part of a building that provides a pathway for airflow needed by heating and air conditioning.

• Plenum rated cables can withstand heated conditions

Riser rated cables are designed for running between floors

• You can use Plenum cables for riser spaces, but you can NOT use riser cables for Plenum spaces.

Unshielded Twisted Pair (UTP): Easier to work with and less expensive than shielded cables

Shielded Twisted Pair (STP): Electrically conductive foil or braided material that is wrapped around the cable

• Reduces Cross Talk and EMI.

Drain Wire: Grounding wire included in shielded cables.

TP cables can be solid or stranded

• Solid has better conductivity, worse flexibility

• Stranded has better flexibility, worse conductivity

Use solid cables in permanent / semi-permanent installations.

Use stranded cables for patch cords and frequently moved cables.

Connector: RJ11

Specs: Connects a PC to a phone jack to establish dial up connection.

Connector: RJ45

Specs: 100 MB Ethernet

Standard: 100BASE-TX

Connector: RJ45

Specs: 100 MB / 1000 MB Ethernet

Standard: 100BASE-T / 1000BASE-T
Notes: Better EMI Protection than Cat 5.

Connector: RJ45

Specs: 10-Gbps Ethernet

Standard: 10GBASE-T
Notes: Has a solid plastic core that keeps the pairs separate and keeps the cable from being bent.

Connector: RJ45

Specs: 10-Gbps Ethernet

Standard: 10GBASE-T
Notes: Cat 6 but with better protection against EMI and crosstalk, along with better performance.

Connector: RJ45 (also GG45 and TERA)

Specs: 10-Gbps Ethernet

Standard: 10GBASE-T
Notes: Has shielding on each twisted pair AND the cable as a whole. (Outdated compared to Cat 6a)

Connector: RJ45 (also GG45 and TERA)

Specs: 40-Gbps and 2 GHz bandwidth

Standard: 10GBASE-T
Notes: Has shielded foiled twited pairs and shielding around each pair of wires within the cable to reduce near end crosstalk, along ith braiding around the group of pairs.

You can use any cable above the one required, but not below. For example, you can use a Cat 6 cable for a standard requiring Cat 5a, but not vice versa. Cat 7 is the exception. It