Commonly known as Ethernet . Using a pair of twisted wires reduces a type of interference called crosstalk.
Resources #
https://en.wikipedia.org/wiki/Twisted_pair
Types #
Shielded Twisted Pair (STP) #
Twisted pairs of wires surrounded by shielding to protect them from EMI.
| Name | Description |
|---|---|
| F/UTP | Foil shields the entire cable; wires are UTP |
| S/UTP | Braid screen shields entire cable; wires are UTP |
| SF/UTP | Braid screen and foil shield the entire cable; wires are UTP |
| S/FTP | Braid screen shields entire cable; foil shields each twisted pair. |
| F/FTP | Foil screen shields the entire cable; foil shields each twisted pair. |
| U/FTP | No overall shielding; each pair inside is shielded with foil. |
Unshielded Twisted Pair (UTP) #
Twisted pairs of wires without shielding; surrounded by plastic jacket. Only use in areas with low or no interference.
Category (Cat) Ratings #
| Cat Rating | Max Frequency | Max Bandwidth | Status with TIA |
| (+/-) | |||
|---|---|---|---|
| Cat 3 | 16 MHz | 16 Mbps | + |
| Cat 4 | 20 MHz | 20 Mbps | - |
| Cat 5 | 100 MHz | 100 Mbps | - |
| Cat 5e | 100 MHz | 1 Gbps | + |
| Cat 6 | 250 MHz | 10 Gbps | + |
| Cat 6a | 500 MHz | 10 Gbps | + |
| Cat 7 | 600 MHz | 10+ Gbps | - |
| Cat 7a | 1000 MHz | 40-100 Gbps | - |
| Cat 8 | 2000 MHz | 25-40 Gbps | - |
- Cat 6 is Limited to 100 meters when using 10/100/1000BaseT networks. With 10GBaseT networks Cat 6 is limited to 55 meters.
- Cat 6a cables can use the full 100-meter length with networks up to 10GBaseT.
- Cat 7a cables can theoretically support 40 Gbps at 50 meters; 100 Gbps at 15 meters.
Connectors #
Telephones used RJ-11. Current wired networks use four-pair 8 position 8 contact (8P8C), but in practice these are called RJ-45 because that’s what they look like.