Unshielded Twisted Pair (UTP) Cabling
UTP is the most common cabling type used in computer networking. It consists of eight conductors within an outer casing. Pairs of the eight conductors are twisted around each other for crosstalk cancellation, hence the name.
Solid vs Stranded
Solid core cabling uses a single solid wire per conductor. Stranded cabling uses multiple wires for each conductor. Solid core cabling is less flexible than stranded and is generally used for permanent installations and is prone to failures if it is bent repeatedly. Ethernet patch cables are most commonly constructed from stranded conductors to be more tolerant of repeated flexing.
Common Types of UTP Cables
Type | Bandwidth | Application | Notes |
CAT3 | 16 Mhz | 10BASE-T Ethernet | Unsuitable for current data networks |
CAT5 | 100 Mhz | 100BASE-T Ethernet | Common in older networks |
CAT5e | 100 Mhz | 100BASE-T Ethernet 1000BASE-T Ethernet |
Constructed the same as CAT5 but with enhanced testing standards. |
CAT6 | 250 Mhz | 10GBASE-T Ethernet | More stringent standards for crosstalk and noise than CAT5e |
Maximum Length
The maximum length for 10/100/1000BASE-T, the maximum length is 100 meters. The maximum length for 10GBASE-T is 55 meters.
Connectors
RJ45 connectors are used to terminate UTP cables, but distinct types are needed for stranded vs solid cabling. For stranded cables, a straight flat blade pierces the cable to make contact with the wires that make up the conductor. In the case of solid conductors, the blades are angled away from each other to trap the solid conductor between them.
RJ-45 Connectors
Stranded Connector Contact
Solid Conductor Contact
Standards
UTP cables can be connected according to two pin assignments; T568A and T568B. The most critical factor is that both ends use the same standard. Patch cables most commonly use the T568B standard.
Pin | T568A | T568B |
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